JP2015226207A - Millimeter wave band filter - Google Patents

Millimeter wave band filter Download PDF

Info

Publication number
JP2015226207A
JP2015226207A JP2014110217A JP2014110217A JP2015226207A JP 2015226207 A JP2015226207 A JP 2015226207A JP 2014110217 A JP2014110217 A JP 2014110217A JP 2014110217 A JP2014110217 A JP 2014110217A JP 2015226207 A JP2015226207 A JP 2015226207A
Authority
JP
Japan
Prior art keywords
waveguide
electromagnetic wave
wave
forming body
wall
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP2014110217A
Other languages
Japanese (ja)
Other versions
JP6315458B2 (en
Inventor
尚志 河村
Hisashi Kawamura
尚志 河村
大谷 昭仁
Akihito Otani
昭仁 大谷
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Anritsu Corp
Original Assignee
Anritsu Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Anritsu Corp filed Critical Anritsu Corp
Priority to JP2014110217A priority Critical patent/JP6315458B2/en
Publication of JP2015226207A publication Critical patent/JP2015226207A/en
Application granted granted Critical
Publication of JP6315458B2 publication Critical patent/JP6315458B2/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Landscapes

  • Control Of Motors That Do Not Use Commutators (AREA)
  • Waveguide Connection Structure (AREA)

Abstract

PROBLEM TO BE SOLVED: To provide a millimeter wave band filter which can be easily manufactured without increasing cost by increasing the number of components or alignment work, and prevents a performance from being reduced by electromagnetic wave leakage.SOLUTION: In the millimeter wave band filter, a first waveguide 21 is moved relatively to a second waveguide 30, and an electromagnetic wave in a resonant frequency that is determined by an interval of radio wave half mirrors fixed to the waveguides is selectively passed. The second waveguide 30 includes: a first waveguide formation body 31 which forms a first waveguide 30a for receiving one end side of the first waveguide 21; and a second waveguide formation body 32 which forms a second waveguide 30b with an aperture smaller than that of the first waveguide 30a. The two waveguide formation bodies 31 and 32 are formed to be connected and disconnected in such a manner that the waveguides become concentric. A groove 60 for electromagnetic wave leakage prevention is provided on an outer wall of the first waveguide 21 in such a manner that a length (p) of the waveguide in a length direction corresponds to a 1/4 wavelength of an electromagnetic wave subjected to leakage prevention.

Description

本発明は、ミリ波帯フィルタに関する。   The present invention relates to a millimeter wave band filter.

近年、ユビキタスネットワーク社会を迎え、電波利用ニーズが高まる中、家庭内のワイヤレスブロードバンド化を実現するWPAN(ワイヤレスパーソナルエリアネットワーク)や安全・安心な運転をサポートするミリ波レーダー等のミリ波帯無線システムが利用され始めている。また、100GHz超無線システム実現への取組も積極的に行われてきている。   In recent years, with the ubiquitous network society and the increasing need for radio wave use, WPAN (wireless personal area network) that realizes wireless broadband in the home and millimeter wave radio systems such as millimeter wave radar that supports safe and secure driving Has begun to be used. In addition, efforts to realize a 100 GHz super wireless system have been actively carried out.

その一方で、60〜70GHz帯の無線システムの2次高調波評価や100GHz超の周波数帯における無線信号の評価については、周波数が高くなるにつれ測定器の雑音レベル及びミキサの変換損失が増加するとともに周波数精度が低下するため、100GHzを超える無線信号の高感度、高精度測定技術が確立されていない状況となっている。しかも、これまでの測定技術では局部発振の高調波を測定結果から分離することができず、不要発射等の厳密な測定が困難となっている。   On the other hand, for the second harmonic evaluation of the radio system in the 60-70 GHz band and the evaluation of the radio signal in the frequency band exceeding 100 GHz, the noise level of the measuring instrument and the conversion loss of the mixer increase as the frequency increases. Since the frequency accuracy is lowered, a high-sensitivity and high-precision measurement technique for wireless signals exceeding 100 GHz has not been established. Moreover, the conventional measurement techniques cannot separate the local oscillation harmonics from the measurement results, making it difficult to accurately measure unwanted emissions.

これらの技術課題を克服し、100GHz超帯域無線信号の高感度・高精度測定を実現するためには、イメージ応答及び高次高調波応答を抑制するためのミリ波帯の狭帯域なフィルタ技術の開発が必要であり、特に、可変周波数型(チューナブル)に適応可能なものが望ましい。   In order to overcome these technical issues and realize high-sensitivity and high-accuracy measurement of 100 GHz super-band radio signals, millimeter-wave narrow-band filter technology for suppressing image response and higher-order harmonic response Development is necessary, and it is particularly desirable to be adaptable to a variable frequency type (tunable).

これを実現するものとして、本願出願人は、光の分野で用いられているファブリペロー共振器をミリ波に応用し、TE10モード(単一モード)を伝搬する導波管構造の導波路の内部に対向させた一対の電波ハーフミラーの間の共振作用により、ミリ波の所望周波数成分を選択的に通過させるミリ波帯フィルタを提案している(特許文献1)。   In order to realize this, the applicant of the present application applies a Fabry-Perot resonator used in the field of light to millimeter waves, and the inside of a waveguide having a waveguide structure that propagates a TE10 mode (single mode). A millimeter-wave band filter that selectively passes a desired frequency component of millimeter waves by a resonance action between a pair of radio wave half mirrors facing each other is proposed (Patent Document 1).

上記特許文献1には、所望周波数帯域の電磁波をTE10モードで伝搬させる導波路を、第1導波管と、その第1導波管の一端側を内側に僅かに隙間のある状態で受け入れる第2導波管とで構成し、第1導波管の先端と第2導波管の内部に電波ハーフミラーを対向するように固定し、その間隔が変化するように一方の導波管に対して他方の導波管をその長手方向に相対的に移動させる構造が開示されている。   In Patent Document 1, a waveguide for propagating electromagnetic waves in a desired frequency band in the TE10 mode is received in a state where the first waveguide and one end side of the first waveguide are slightly spaced inside. It is composed of two waveguides, and a radio wave half mirror is fixed so as to be opposed to the tip of the first waveguide and the inside of the second waveguide. A structure in which the other waveguide is moved relatively in the longitudinal direction is disclosed.

上記構造のミリ波体フィルタであれば、波面変換による特性劣化がなく、電波ハーフミラーの設計に高い自由度を与えることができ、空間放射による損失が少なくて済み、しかも、一対の電波ハーフミラーの間隔を変化させることでフィルタの共振周波数を可変することができる。   With the millimeter wave filter having the above structure, there is no deterioration in characteristics due to wavefront conversion, a high degree of freedom can be given to the design of the radio wave half mirror, the loss due to spatial radiation can be reduced, and a pair of radio wave half mirrors. The resonance frequency of the filter can be varied by changing the interval.

ただし、この構造のミリ波帯フィルタを実際に製造する場合、内側の第1導波管の外周壁と、外側の第2導波管の内周壁との間に、導波管同士の長手方向の相対移動が可能なように隙間を設ける必要があるが、その隙間は、一対の電波ハーフミラーの間に形成される共振器の空間と連続しており、電波ハーフミラー間を往復する電磁波がこの隙間を介して外部に漏れることでフィルタとしての特性が低下してしまう。   However, when the millimeter wave band filter having this structure is actually manufactured, the longitudinal direction of the waveguides is between the outer peripheral wall of the inner first waveguide and the inner peripheral wall of the outer second waveguide. However, the gap is continuous with the resonator space formed between the pair of radio wave half mirrors. By leaking outside through this gap, the characteristics as a filter are degraded.

したがって、この隙間を可能な限り小さくする必要がある。例えば、導波路の口径2ミリ×1ミリ程度の導波管の場合、容認される隙間は数10μm(例えば20〜30μm)以下であるが、これは顕微鏡で確認しなくてはならない寸法である。ところが、上記構造のミリ波帯フィルタのように、第2導波路の内部に第1導波管の先端が入り込む構造では、隙間部分を外部から観察することができず、その隙間のばらつきを確認できず、双方の位置合わせが極めて困難となる。   Therefore, it is necessary to make this gap as small as possible. For example, in the case of a waveguide having a waveguide diameter of about 2 mm × 1 mm, the allowable gap is several tens μm (for example, 20 to 30 μm) or less, which is a dimension that must be confirmed with a microscope. . However, in the structure in which the tip of the first waveguide enters the second waveguide, such as the millimeter-wave band filter having the above structure, the gap portion cannot be observed from the outside, and the variation in the gap is confirmed. This is not possible, and it is extremely difficult to align the two.

この問題を解決する技術として、本願出願人は、特許文献2において、外側の第2導波管を、厚さ一定の板状部に内側の第1導波管の一端側を受け入れる口径の第1導波路を形成する角穴が厚さ方向に貫通形成された第1導波路形成体と、厚さ一定の板状部に第1導波管と同口径の第2導波路を形成する角穴が厚さ方向に貫通形成された第2導波路形成体とで構成し、第1導波路形成体と第2導波路形成体の板状部を、それぞれの角穴同士が同心に連続するように重ね合わせた状態で連結、分離可能に形成する技術を開示している。   As a technique for solving this problem, the applicant of the present invention in Patent Document 2 has a diameter of the second waveguide that receives the one end side of the first waveguide on the inner side in the plate-shaped portion having a constant thickness. A first waveguide forming body in which square holes forming one waveguide are formed penetrating in the thickness direction, and a corner for forming a second waveguide having the same diameter as the first waveguide in a plate-like portion having a constant thickness. It comprises a second waveguide formation body in which holes are formed penetrating in the thickness direction, and the plate-like portions of the first waveguide formation body and the second waveguide formation body are concentrically continuous with each other. In this way, a technology is disclosed that can be connected and separated in a superposed state.

この技術を採用することで、内側の第1導波管の外周と外側の第2導波管の第1導波路を形成する角穴との隙間を第1導波路形成体側から観察することができ、その位置合わせを正確に行うことができ、その位置合わせの後に、第2導波路形成体を第1導波路形成体に対して予め位置決めされた位置に連結すれば、第1導波路に対して第2導波路が傾くこともなく、第1導波管の導波路を含めて3つの導波路の位置合わせを正確に行うことができ、フィルタ特性を高く維持できる。   By adopting this technology, the gap between the outer periphery of the inner first waveguide and the square hole forming the first waveguide of the outer second waveguide can be observed from the first waveguide forming body side. The alignment can be performed accurately, and after the alignment, if the second waveguide forming body is connected to a position previously positioned with respect to the first waveguide forming body, the first waveguide is formed. On the other hand, the second waveguide is not inclined, and the alignment of the three waveguides including the waveguide of the first waveguide can be accurately performed, and the filter characteristics can be maintained high.

また、上記特許文献2では、上記構造により導波管間の少ない隙間を均等に設けた上で、導波管の間に形成される隙間からの電磁波の漏出を抑制するために、第1導波路形成体を挟んで第2導波路形成体と反対側に重なり、第1導波管を通過させる角穴が厚さ方向に貫通形成され、その角穴の内周に電磁波漏出防止用の所定深さの溝を周回形成するチョーク形成体を設ける技術も開示されている。   Further, in Patent Document 2, the first structure is used in order to suppress leakage of electromagnetic waves from the gap formed between the waveguides after the gaps between the waveguides are uniformly provided by the above structure. A square hole is formed in the thickness direction so as to pass through the first waveguide and overlap with the opposite side of the second waveguide formation body with the waveguide formation body interposed therebetween. There is also disclosed a technique of providing a choke forming body that forms a groove having a depth.

特開2013−138401号公報JP 2013-138401 A 特開2013−247381号公報JP 2013-247381 A

しかしながら、上記特許文献2の構造のミリ波帯フィルタにおいても、さらに解決すべき新たな課題が明らかになった。   However, even in the millimeter waveband filter having the structure of Patent Document 2, a new problem to be solved has been clarified.

即ち、上記のように外側の導波管の内壁に電磁波漏出防止用の溝を設けた構造のフィルタの特性を詳細に調べてみると、内側の導波管の先端(電波ハーフミラーが固定されている部分)から外側の導波管の内壁に設けた溝までの間(以下、不要共振器長と呼ぶ)で不要共振が生じることが認められ、その不要共振周波数が導波管の移動により変化することがわかった。   That is, when the characteristics of the filter having the structure in which the groove for preventing electromagnetic wave leakage is provided on the inner wall of the outer waveguide as described above are examined in detail, the tip of the inner waveguide (the radio wave half mirror is fixed). It is recognized that unnecessary resonance occurs between the groove and the groove provided on the inner wall of the outer waveguide (hereinafter referred to as unnecessary resonator length), and the unnecessary resonance frequency is caused by the movement of the waveguide. I found that it changed.

ここで、一対の電波ハーフミラーの間隔で決まるフィルタ自体の共振周波数(フィルタ共振周波数)は、そのミラー間隔が小さくなるほど高くなるのに対し、上記不要共振周波数はミラー間隔が小さくなるほど低くなる。つまり、ミラー間隔の変化に対し、両共振周波数の変化方向は逆向きとなり、フィルタの共振周波数を大きく動かした場合、フィルタの共振周波数と上記不要共振周波数が重なり、不要共振がフィルタ共振特性を乱すことになる。   Here, the resonance frequency (filter resonance frequency) of the filter itself determined by the interval between the pair of radio wave half mirrors increases as the mirror interval decreases, whereas the unnecessary resonance frequency decreases as the mirror interval decreases. In other words, the change direction of both resonance frequencies is opposite to the change of the mirror interval, and when the resonance frequency of the filter is moved greatly, the resonance frequency of the filter overlaps with the unnecessary resonance frequency, and the unnecessary resonance disturbs the filter resonance characteristics. It will be.

これを防ぐために、ミラー間隔が最も広い状態のときに、不要共振器長をそのミラー間隔より十分広くすることが考えられるが、上記不要共振は電磁波の波長の1/2だけでなく、その奇数倍でも発生し、高次の不要共振の影響が避けられない。また不要共振器長を極端に長くすると内側の導波管と外側の導波管とがオーバーラップする長さを大きくする必要があり、フィルタ全体が大型化してしまう。   In order to prevent this, it is conceivable to make the length of the unnecessary resonator sufficiently wider than the mirror interval when the mirror interval is the widest. However, the unnecessary resonance is not only 1/2 of the wavelength of the electromagnetic wave but also an odd number thereof. The effect of high-order unnecessary resonance is unavoidable. Further, if the length of the unnecessary resonator is made extremely long, it is necessary to increase the length of overlap between the inner waveguide and the outer waveguide, and the entire filter is increased in size.

また、上記のように、第1導波路形成体にチョーク形成体を重ね合わせる際に、その両形成体の角穴の位置が一致するように位置決めする必要があり、チョーク形成体という部品の増加およびその位置合わせという工程の増加によるコスト高を招くという問題もあった。   In addition, as described above, when the choke forming body is overlaid on the first waveguide forming body, it is necessary to position the two hole forming holes so that the positions of the square holes coincide with each other. In addition, there is a problem in that the cost is increased due to an increase in the process of alignment.

なお、チョーク形成体を別体として設けずに、電磁波漏出防止用の溝を第1導波路形成体の角穴の内周壁に設けることは可能であるが、長期に渡って電気的に安定な特性を確保するための金メッキ処理を行なう際に、上記したように深さ1mmで幅0.2mmの溝にメッキ液を進入させることは極めて困難であり、上記したような第1導波路形成体と別体チョーク形成体を設けざるを得なかった。   Although it is possible to provide a groove for preventing electromagnetic wave leakage on the inner peripheral wall of the square hole of the first waveguide forming body without providing the choke forming body as a separate body, it is electrically stable for a long time. When performing the gold plating process to ensure the characteristics, it is extremely difficult to allow the plating solution to enter the groove having a depth of 1 mm and a width of 0.2 mm as described above, and the first waveguide forming body as described above. And a separate chalk forming body had to be provided.

本発明は、上記の新たな課題を解決し、部品点数や位置合わせ作業の増加によるコスト高を招くことなく、容易に製造でき、かつ電磁波漏出による性能低下のないミリ波帯フィルタを提供することを目的としている。   The present invention solves the above-mentioned new problems, and provides a millimeter-wave band filter that can be easily manufactured without incurring high costs due to an increase in the number of parts and alignment work, and that does not deteriorate in performance due to electromagnetic leakage. It is an object.

前記目的を達成するために、本発明の請求項1のミリ波帯フィルタは、
ミリ波帯の所定周波数範囲の電磁波をTE10モードで伝搬させる口径の導波路(22)を有する第1導波管(21)と、
前記第1導波管の外径より大きく、且つ、前記所定周波数範囲の電磁波をTE10モードで伝搬させる口径を有し、前記第1導波管の一端側をその外周に隙間のある状態で受け入れる第1導波路(30a)と、該第1導波路より小さい口径の第2導波路(30b)とが同心に連続するように形成されている第2導波管(30)と、
前記所定周波数範囲の電磁波の一部を透過させ、一部を反射させる特性をもち、一方が前記第1導波管の前記一端側の導波路に固定され、他方が前記第2導波管の前記第1導波路と前記第2導波路の境界部に固定された一対の電波ハーフミラー(40A、40B)と、
前記一対の電波ハーフミラーの間隔が変化するように前記第1導波管を前記第2導波管に対して相対移動させて、前記所定周波数範囲の電磁波のうち前記一対の電波ハーフミラーの間隔で決まる共振周波数の電磁波を選択的に通過させる間隔可変手段(51)とを有し、
前記第2導波管が、
厚さ一定の板状部を有し、該板状部に前記第1導波路を形成する角穴が厚さ方向に貫通形成された第1導波路形成体(31)と、
厚さ一定の板状部を有し、該板状部に前記第2導波路を形成する角穴が厚さ方向に貫通形成された第2導波路形成体(32)とを含み、
前記第1導波路形成体と前記第2導波路形成体とが、前記角穴同士が同心に連続するように前記板状部同士を重ね合わせた状態で連結、分離可能に形成されたミリ波帯フィルタにおいて、
前記第2導波管の前記第1導波路の内壁に対向する前記第1導波管の外壁には、導波路の長手方向に沿った長さが漏出防止対象の電磁波の1/4波長相当となる溝(60)が形成され、該溝によって前記第1導波管の外壁と前記第2導波管の前記第1導波路の内壁との隙間からの電磁波漏出を防止することを特徴する。
In order to achieve the above object, the millimeter waveband filter according to claim 1 of the present invention comprises:
A first waveguide (21) having a waveguide (22) having a diameter for propagating electromagnetic waves in a predetermined frequency range in the millimeter wave band in a TE10 mode;
It has a diameter larger than the outer diameter of the first waveguide and propagates the electromagnetic wave in the predetermined frequency range in the TE10 mode, and accepts one end of the first waveguide with a gap on the outer periphery thereof. A second waveguide (30) formed such that the first waveguide (30a) and the second waveguide (30b) having a smaller diameter than the first waveguide are concentrically continuous;
The electromagnetic wave has a characteristic of transmitting a part of the electromagnetic wave in the predetermined frequency range and reflecting a part thereof, one of which is fixed to the waveguide on the one end side of the first waveguide and the other of the second waveguide. A pair of radio wave half mirrors (40A, 40B) fixed to the boundary between the first waveguide and the second waveguide;
The first waveguide is moved relative to the second waveguide so that the distance between the pair of radio wave half mirrors changes, and the distance between the pair of radio wave half mirrors among the electromagnetic waves in the predetermined frequency range. And an interval variable means (51) for selectively passing an electromagnetic wave having a resonance frequency determined by
The second waveguide is
A first waveguide forming body (31) having a plate-like portion having a constant thickness and having a square hole penetrating the plate-like portion forming the first waveguide in the thickness direction;
A second waveguide forming body (32) having a plate-like portion having a constant thickness, and a square hole forming the second waveguide is formed in the plate-like portion in the thickness direction;
The millimeter wave formed so that the first waveguide forming body and the second waveguide forming body can be connected and separated in a state where the plate-like portions are overlapped so that the square holes are concentrically continuous. In the band filter,
The outer wall of the first waveguide facing the inner wall of the first waveguide of the second waveguide has a length along the longitudinal direction of the waveguide corresponding to a quarter wavelength of the electromagnetic wave to be prevented from leaking. A groove (60) is formed, and the groove prevents leakage of electromagnetic waves from a gap between the outer wall of the first waveguide and the inner wall of the first waveguide of the second waveguide. .

このように、本発明のミリ波帯フィルタは、第2導波管を、板状部を厚さ方向に貫通する角穴により第1導波管の一端側を受け入れるための第1導波路を形成する第1導波路形成体と、第1導波路より小さい口径で板状部を厚さ方向に貫通する角穴により第2導波路を形成する第2導波路形成体とを含む構成とし、これら二つの導波路形成体を角穴同士が同心となるように連結、分離可能に形成するとともに、電磁波漏出防止用の溝を、内側の第1導波管の外壁にその導波路の長手方向に沿った長さが漏出防止対象の電磁波の1/4波長相当となるように設けている。   As described above, the millimeter-wave band filter of the present invention includes the first waveguide for receiving the one end side of the first waveguide by the square hole penetrating the plate-like portion in the thickness direction. A configuration including a first waveguide forming body to be formed and a second waveguide forming body that forms a second waveguide by a square hole that penetrates the plate-like portion in the thickness direction with a smaller aperture than the first waveguide; These two waveguide forming bodies are formed so that the square holes are concentrically connected and separated, and a groove for preventing electromagnetic wave leakage is formed on the outer wall of the inner first waveguide in the longitudinal direction of the waveguide. Is provided so that the length along the line corresponds to a quarter wavelength of the electromagnetic wave to be prevented from leaking.

このため、従来のように、チョーク形成体を別個に用意する必要がなくなり、部品点数および作業工数を大幅に減少させることができ、部品点数や位置合わせ作業の増加によるコスト高を招くことなく、容易に製造でき、かつ電磁波漏出による性能低下のないミリ波帯フィルタを実現できる。   For this reason, unlike the conventional case, there is no need to prepare a separate choke forming body, the number of parts and work man-hours can be greatly reduced, without incurring high costs due to an increase in the number of parts and alignment work, It is possible to realize a millimeter wave band filter that can be easily manufactured and does not deteriorate in performance due to electromagnetic leakage.

本発明の実施形態の構成を示す図The figure which shows the structure of embodiment of this invention 電波ハーフミラーの構造例を示す図Diagram showing a structural example of a radio wave half mirror 導波管の位置決め作業の説明図Illustration of waveguide positioning work 隙間に対して電磁波漏出防止の溝の長さ方向を変えた場合のモデル図Model diagram when the length direction of the electromagnetic wave leakage prevention groove is changed with respect to the gap 隙間を伝搬する電磁波の伝搬方向と電磁波漏出防止用の溝の長さ方向が直交するモデルのシミュレーション結果Simulation results of a model in which the propagation direction of the electromagnetic wave propagating through the gap is orthogonal to the length direction of the groove for preventing electromagnetic wave leakage 隙間を伝搬する電磁波の伝搬方向と電磁波漏出防止用の溝の長さ方向が平行なモデルのシミュレーション結果Simulation results of a model in which the propagation direction of the electromagnetic wave propagating through the gap is parallel to the length direction of the groove for preventing electromagnetic wave leakage 第1導波管の別の構造例を示す図The figure which shows another structural example of a 1st waveguide

以下、図面に基づいて本発明の実施の形態を説明する。
図1は、本発明のミリ波帯フィルタ20の基本構造を示している。
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a basic structure of a millimeter wave band filter 20 of the present invention.

図1の(a)の側面図に示すように、このミリ波帯フィルタ20は、第1導波管21、第2導波管30、一対の電波ハーフミラー40A、40Bおよび支持機構50を有している。   As shown in the side view of FIG. 1A, the millimeter wave band filter 20 includes a first waveguide 21, a second waveguide 30, a pair of radio wave half mirrors 40A and 40B, and a support mechanism 50. doing.

第1導波管21は、その本体をなす角筒部21aとその一端側に設けられたフランジ21bとを有し、角筒部21aの内部は、ミリ波帯の所定周波数範囲(例えば110〜140GHz)の電磁波をTE10モード(単一モード)で伝搬させる口径(例えば2.032mm×1.016mm)の導波路22が一端側から他端側に連続して形成されている。   The first waveguide 21 has a rectangular tube portion 21a that forms a main body thereof and a flange 21b provided on one end thereof, and the inside of the rectangular tube portion 21a has a predetermined frequency range (for example, 110 to 110 mm) in the millimeter wave band. A waveguide 22 having a diameter (for example, 2.032 mm × 1.016 mm) for propagating an electromagnetic wave of 140 GHz in the TE10 mode (single mode) is continuously formed from one end side to the other end side.

第2導波管30は、第1導波管21の角筒部21aの外径より僅か(例えば縦横ともに30μmずつ)に大きく、且つ、前記所定周波数範囲の電磁波をTE10モードで伝搬させる口径を有し、第1導波管21の角筒部21aの先端をその外周にほぼ一定の隙間のある状態で同心に受け入れる第1導波路30aと、第1導波路30aの口径より小さい(ここでは第1導波管21の導波路22と同口径とする)第2導波路30bとが同心で且つ捩れのない状態で連続するように形成されている。   The second waveguide 30 is slightly larger than the outer diameter of the rectangular tube portion 21a of the first waveguide 21 (for example, 30 μm in both vertical and horizontal directions), and has a diameter for propagating electromagnetic waves in the predetermined frequency range in the TE10 mode. A first waveguide 30a that concentrically receives the tip of the rectangular tube portion 21a of the first waveguide 21 with a substantially constant gap on the outer periphery thereof, and smaller than the aperture of the first waveguide 30a (here, The second waveguide 30b (having the same diameter as the waveguide 22 of the first waveguide 21) is formed so as to be concentric and continuous without being twisted.

ここで、第1導波管21の角筒部21aの外形は、導波路22の口径に肉厚分(例えば0.3mm)を加えた寸法であり、第2導波管30の第1導波路30aの口径は、第1導波管21の角筒部21aの外形寸法に、導波管同士の移動に必要な隙間(例えば30μm)を加えた寸法に設定されている。   Here, the outer shape of the rectangular tube portion 21 a of the first waveguide 21 is a dimension obtained by adding a thickness (for example, 0.3 mm) to the diameter of the waveguide 22, and the first guide of the second waveguide 30. The diameter of the waveguide 30a is set to a dimension obtained by adding a gap (for example, 30 μm) necessary for movement between the waveguides to the outer dimension of the rectangular tube portion 21a of the first waveguide 21.

そして、第1導波管21の角筒部21aの先端部には、前記所定周波数範囲の電磁波の一部を透過させ、一部を反射させる特性をもつ電波ハーフミラー40Aが導波路22を塞ぐ状態で固定され、その電波ハーフミラー40Aと対をなす電波ハーフミラー40Bが第2導波管30の第1導波路30aと第2導波路30bの境界(図の例では第2導波路30bの先端)に固定されている。   A radio wave half mirror 40A having a characteristic of transmitting a part of the electromagnetic wave in the predetermined frequency range and reflecting a part of the electromagnetic wave in the predetermined frequency range closes the waveguide 22 at the distal end of the rectangular tube part 21a of the first waveguide 21. The radio wave half mirror 40B which is fixed in a state and forms a pair with the radio wave half mirror 40A is a boundary between the first waveguide 30a and the second waveguide 30b of the second waveguide 30 (in the example of the figure, the second waveguide 30b It is fixed to the tip.

一対の電波ハーフミラー40A、40Bは、例えば図2に示しているように、固定される導波路22、30bの口径に対応した大きさの長方形で電磁波に対する反射性を有する金属製の基板41と、その基板41の中央部に基板長辺方向に所定高さで伸び、電磁波に対する透過性を有するスリット42とを有し、基板41の外周が各導波路22、30bの内壁または先端縁に接触する状態で各導波路の先端部に固定されていて、基板41の厚さ、スリット42の高さ、長さ等に対応した透過率で電磁波を透過させる。   For example, as shown in FIG. 2, the pair of radio wave half mirrors 40A and 40B is a rectangle having a size corresponding to the diameter of the waveguides 22 and 30b to be fixed, and a metal substrate 41 having reflectivity for electromagnetic waves. The substrate 41 has a slit 42 that extends at a predetermined height in the long side direction of the substrate 41 and is transparent to electromagnetic waves, and the outer periphery of the substrate 41 contacts the inner wall or the tip edge of each of the waveguides 22 and 30b. In this state, the electromagnetic wave is transmitted at a transmittance corresponding to the thickness of the substrate 41, the height and the length of the slit 42, and the like.

なお、ここでは、スリット42の高さを一定としているが、これは基本構造例であり、スリット形状はこの例に限定されない。電波ハーフミラーとして要求される特性は前記所定周波数範囲の電磁波に対する透過率がほぼ一定となることであり、その特性が得られるように、スリット42の形状を変化させることができる。例えば、スリット42の中央部の高さが両端部の高さより小となるリッジ形にし、基板41の厚さ、スリット42の中央部の高さと幅、両端部の高さと幅を選ぶことで、前記所定周波数範囲の電磁波に対する透過率の平坦化が可能である。   Here, the height of the slit 42 is constant, but this is a basic structure example, and the slit shape is not limited to this example. The characteristic required for the radio wave half mirror is that the transmittance with respect to the electromagnetic wave in the predetermined frequency range is substantially constant, and the shape of the slit 42 can be changed so as to obtain the characteristic. For example, by making the ridge shape in which the height of the central portion of the slit 42 is smaller than the height of both end portions, by selecting the thickness of the substrate 41, the height and width of the central portion of the slit 42, the height and width of both end portions, The transmittance for electromagnetic waves in the predetermined frequency range can be flattened.

このような構造をもつミリ波帯フィルタ20では、互いに対向する一対の電波ハーフミラー40A、40Bの間隔を半波長として共振する平面型のファブリペロー共振器が成され、その共振周波数を中心とする周波数成分だけが選択的に通過できる状態となる。   In the millimeter wave band filter 20 having such a structure, a planar Fabry-Perot resonator that resonates with the interval between the pair of radio wave half mirrors 40A and 40B facing each other as a half wavelength is formed, and the resonance frequency is the center. Only the frequency component can be selectively passed.

しかも、各導波路22、30a、30bは、ミリ波帯において極めて低損失の閉鎖型の伝送路としての導波管構造で形成され、進行方向に直交する平面にのみ電界が存在するTE波を用いるから、波面変換などの処理は不要で、共振器で抽出された信号成分のみをTE10モードで極めて低損失に出力させることができる。   In addition, each of the waveguides 22, 30a, and 30b is formed with a waveguide structure as a closed transmission line with extremely low loss in the millimeter wave band, and a TE wave in which an electric field exists only in a plane orthogonal to the traveling direction. Since it is used, processing such as wavefront conversion is unnecessary, and only the signal component extracted by the resonator can be output in the TE10 mode with extremely low loss.

なお、第1導波管21と第2導波管30は、それらが有する導波路22、30a、30bが同心でねじれの無い状態で連続し、且つ一対の電波ハーフミラー40A、40Bが平行に対向した姿勢を保ちつつ、その間隔を可変させることができる支持機構50によって支持されている。この支持機構50は、両導波管21、30を堅固に支持するとともに、一対の電波ハーフミラー40A、40Bの間隔が変化するように両導波管21、30を導波路の長さ方向に沿って相対移動させる間隔可変手段51を含むが、その構成は任意である。   The first waveguide 21 and the second waveguide 30 are continuous with the waveguides 22, 30 a, 30 b included in the first waveguide 21 and the second waveguide 30 being concentric, and the pair of radio wave half mirrors 40 </ b> A, 40 </ b> B are parallel to each other. It is supported by the support mechanism 50 which can change the space | interval, maintaining the opposing attitude | position. The support mechanism 50 firmly supports both the waveguides 21 and 30 and moves both the waveguides 21 and 30 in the length direction of the waveguide so that the distance between the pair of radio wave half mirrors 40A and 40B changes. Although the interval variable means 51 for relatively moving along is included, the configuration is arbitrary.

このように、TE10モードのみを伝送する導波路が連続し、その内部に平面型の一対の電波ハーフミラー40A、40Bで形成された共振器を設けた構造であるから、平面波を入射するための特別な工夫が必要なくなり、また電波ハーフミラーも平面波を透過させる必要がなく任意の形状をとることができる。   As described above, since the waveguide for transmitting only the TE10 mode is continuous and the resonator formed by the pair of planar radio wave half mirrors 40A and 40B is provided therein, the plane wave is incident. No special device is required, and the radio wave half mirror does not need to transmit a plane wave and can take any shape.

また、フィルタ全体としてほぼ密閉型となり、外部空間への放射による損失が少なく、ミリ波帯において、極めて高い選択特性を実現できる。   Further, the filter as a whole is almost hermetically sealed so that there is little loss due to radiation to the external space, and extremely high selection characteristics can be realized in the millimeter wave band.

そして、この実施形態のミリ波帯フィルタ20では、図1の(b)に示しているように、第2導波管30を、厚さ一定の板状で第1導波路30aを形成する角穴が一面31a側から反対面31b側に貫通形成された第1導波路形成体31と、厚さ一定の板状で第2導波路30bを形成する角穴が一面32a側から反対面32b側に貫通形成された第2導波路形成体32とを、それら角穴同士が同心に連続するように重ね合わせた状態でネジ止めなどにより連結、分離可能に形成されている。図中、符号31cはネジ締付用穴、32cはネジ貫通用穴、符号39は連結用のネジである。   In the millimeter-wave band filter 20 of this embodiment, as shown in FIG. 1B, the second waveguide 30 is formed into a plate having a constant thickness, and the angle at which the first waveguide 30a is formed. The first waveguide forming body 31 having a hole penetrating from the one surface 31a side to the opposite surface 31b side, and the square hole forming the second waveguide 30b with a constant thickness from the one surface 32a side to the opposite surface 32b side The second waveguide forming body 32 formed so as to penetrate through the two is formed so as to be connected and separated by screwing or the like in a state where the square holes are overlapped so as to be concentric. In the figure, reference numeral 31c is a screw tightening hole, 32c is a screw penetration hole, and 39 is a connecting screw.

なお、ここでは、最も簡単な形状例として、第1導波路形成体31と第2導波路形成体32が厚さ一定の板体の例を示しているが、導波路30a、30bを形成する角穴が貫通形成されている部分だけが厚さ一定の板状部で、その板状部同士を重ね合わせた状態で連結、分離できる形状であればよく、外周部の形状は任意である。   Here, as an example of the simplest shape, an example in which the first waveguide forming body 31 and the second waveguide forming body 32 are plate bodies having a constant thickness is shown, but the waveguides 30a and 30b are formed. Only the portion where the square hole is formed through is a plate-like portion having a constant thickness, and any shape that can be connected and separated in a state where the plate-like portions are overlapped with each other may be used, and the shape of the outer peripheral portion is arbitrary.

このように第2導波管30が、単一口径の導波路が厚さ方向に貫通形成された板状体同士を重ね合わせて一体的に連結した構造であるから、異口径の第1導波路30a、第2導波路30bをそれぞれ別部材に正確に製作することができ、また、それらが同心に連続する状態で重なり合う位置を容易に特定することができ、高精度な第2導波管30を実現できる。また、第1導波路30aと第2導波路30bの境界に電波ハーフミラー40Bを固定する作業も板体の表面で行えるから極めて容易に行え、正しい姿勢に固定できる。   As described above, the second waveguide 30 has a structure in which the single-diameter waveguides are formed by penetrating and integrally connecting the plate-like bodies formed by penetrating the single-diameter waveguide in the thickness direction. The waveguide 30a and the second waveguide 30b can be accurately manufactured as separate members, respectively, and the overlapping position of the waveguide 30a and the second waveguide 30b can be easily specified in a state where they are concentrically continuous. 30 can be realized. In addition, the work of fixing the radio wave half mirror 40B to the boundary between the first waveguide 30a and the second waveguide 30b can be performed on the surface of the plate body, which is extremely easy and can be fixed in the correct posture.

また、第2導波路形成体32を第1導波路形成体31に固定する前に、第1導波管21と第1導波路形成体31とを支持機構50に支持させた状態で、第1導波路形成体31の反対面31b側から角穴部分を顕微鏡等で観察すれば、第1導波管21の角筒部21aの外壁と第1導波路30aの内壁との隙間を容易に確認できる。   In addition, the first waveguide 21 and the first waveguide forming body 31 are supported by the support mechanism 50 before the second waveguide forming body 32 is fixed to the first waveguide forming body 31. If the square hole portion is observed with a microscope or the like from the opposite surface 31b side of the one waveguide forming body 31, a gap between the outer wall of the rectangular tube portion 21a of the first waveguide 21 and the inner wall of the first waveguide 30a can be easily obtained. I can confirm.

例えば、図3の(a)のように、第1導波路30aに対して第1導波管21の角筒部21aが傾き(捩れ)、偏心している画像が観察された場合、支持機構50により、第1導波管21の第1導波路形成板31に対する中心位置および角度を合わせ、図3の(b)のように、両者の隙間が全周にわたって均一となる(同心で捩れがない状態)ように位置決めする。これによって、導波管同士の接触が防止でき、磨耗のない状態で周波数可変を円滑に行うことができる。そして、この位置決めの後に、第2導波路形成体32を第1導波路形成体31の予め特定された位置に固定すれば、第1導波管21の導波路を含めて3つの連続した導波路を正確に同心配列できる。   For example, as shown in FIG. 3A, when an image in which the rectangular tube portion 21a of the first waveguide 21 is tilted (twisted) and eccentric with respect to the first waveguide 30a is observed, the support mechanism 50 is used. Thus, the center position and the angle of the first waveguide 21 with respect to the first waveguide forming plate 31 are matched, and as shown in FIG. 3B, the gap between them becomes uniform over the entire circumference (concentric and no twisting). Position). As a result, contact between the waveguides can be prevented, and the frequency can be changed smoothly without wear. After the positioning, if the second waveguide forming body 32 is fixed at a predetermined position of the first waveguide forming body 31, three continuous guides including the waveguide of the first waveguide 21 are provided. Waveguides can be accurately concentrically arranged.

上記のように第1導波管21を第2導波管30に対して相対的に移動させる構造では、第1導波管21の角筒部21aの外周壁と第2導波管30の第1導波路30aの内周壁との間に隙間が必要となるが、この隙間は、構造上、一対の電波ハーフミラー40A、40Bの間に形成される共振器と連続しているので、共振器内の電磁波がこの隙間から漏出して、フィルタとしての損失低下を招く。このため、前記したように少ない隙間で導波管同士の位置調整が行える構造を採用しているが、たとえ前記したように20〜30μm程度の隙間に抑えても電磁波の漏出を完全に防ぐことはできない。   In the structure in which the first waveguide 21 is moved relative to the second waveguide 30 as described above, the outer peripheral wall of the rectangular tube portion 21a of the first waveguide 21 and the second waveguide 30 A gap is required between the first waveguide 30a and the inner wall of the first waveguide 30a. This gap is structurally continuous with the resonator formed between the pair of radio wave half mirrors 40A and 40B. The electromagnetic wave in the vessel leaks from this gap, resulting in a loss reduction as a filter. For this reason, as described above, the structure that can adjust the position of the waveguides with a small gap is adopted, but even if it is suppressed to a gap of about 20 to 30 μm as described above, the leakage of electromagnetic waves is completely prevented. I can't.

この電磁波漏出を防止する方法として、前記した特許文献1、2では、外側の第2導波管30の内壁に、導波路の長さ方向と直交する方向に漏出対象の電磁波の波長の1/4相当の深さで溝を設けているが、この従来方法では、前記したように不要共振による特性低下や部品およびその位置合わせ作業の増加によるコスト高が避けられない。   As a method for preventing the leakage of electromagnetic waves, in Patent Documents 1 and 2 described above, the wavelength of the electromagnetic wave to be leaked in the direction perpendicular to the length direction of the waveguide is formed on the inner wall of the outer second waveguide 30. Although the grooves are provided at a depth corresponding to 4, this conventional method inevitably increases the cost due to the deterioration of characteristics due to unnecessary resonance and the increase of parts and their alignment operations.

この不要共振の問題は、内側の第1導波管21の角筒部21a側に電磁波漏出防止用の溝を設けること解決可能と思われるが、前記したように電磁波漏出防止用の溝として必要な深さはほぼ1mm程度であり、これを従来装置のように導波路の長さ方向に直交する向きに設けることは、第1導波管21の角筒部21aの内径寸法(ほぼ2mm×1mm)から考えて実現困難である。   This unnecessary resonance problem can be solved by providing a groove for preventing electromagnetic wave leakage on the rectangular tube portion 21a side of the inner first waveguide 21, but as described above, it is necessary as a groove for preventing electromagnetic wave leakage. The depth is about 1 mm. Providing it in a direction orthogonal to the length direction of the waveguide as in the conventional device is that the inner diameter of the rectangular tube portion 21a of the first waveguide 21 (approximately 2 mm × 1 mm) is difficult to realize.

そこで、発明者らは、溝の電磁波漏出防止作用を示す長さ方向を導波路の長さ方向に合わせることができないかを検討した。   Therefore, the inventors have examined whether the length direction of the groove that prevents electromagnetic wave leakage can be matched with the length direction of the waveguide.

図4の(a)は、30μmの隙間gが形成する導波路に直交するように長さ(深さ)p=1.1mm、幅q=0.3mmの溝を設けた従来モデルであり、図4の(b)は、30μmの隙間gが形成する導波路に沿って長さp=1.1mm、深さq=0.2mmの溝を設けた検討モデルである。従来モデルの透過特性は図5のように得られ、検討モデルの透過特性は図6のように得られた。   FIG. 4A shows a conventional model in which a groove having a length (depth) p = 1.1 mm and a width q = 0.3 mm is provided so as to be orthogonal to the waveguide formed by the gap g of 30 μm. FIG. 4B is a study model in which a groove having a length p = 1.1 mm and a depth q = 0.2 mm is provided along a waveguide formed by a gap g of 30 μm. The transmission characteristics of the conventional model were obtained as shown in FIG. 5, and the transmission characteristics of the study model were obtained as shown in FIG.

70〜120GHzの範囲で両者を比較すると、従来モデルは検討モデルに対して大きな減衰が得られ、特に94GHzでは急峻に減衰していることがわかる。しかしながら、検討モデルにおいても、上記周波数範囲でほぼ10dBの減衰が得られており、この減衰量で不十分であれば、同一形状の溝を導波路の長さ方向に沿って複数段形成することで対応できる。この結果から、電磁波漏出防止用の溝については、その電磁波漏出防止作用を示す長さ方向を導波路の長さ方向に合わせて形成することが可能であることが確認でき、この技術は、肉厚が0.3mm程度の第1導波管21であれば十分適用できる。   Comparing the two in the range of 70 to 120 GHz, it can be seen that the conventional model is greatly attenuated with respect to the model to be examined, and particularly at 94 GHz, it is steeply attenuated. However, even in the study model, attenuation of about 10 dB is obtained in the above frequency range, and if this attenuation is insufficient, a plurality of grooves having the same shape are formed along the length direction of the waveguide. It can respond. From this result, it can be confirmed that the groove for preventing electromagnetic wave leakage can be formed by matching the length direction showing the electromagnetic wave leakage preventing action with the length direction of the waveguide. The first waveguide 21 having a thickness of about 0.3 mm is sufficiently applicable.

図1に示したミリ波帯フィルタ20は上記検討技術を採用したものであり、第2導波管30の第1導波路形成体31の内壁に隙間を挟んで対向する第1導波管21の角筒部21aの先端に近い上下(長辺側)の外壁に、電磁波漏出防止用の溝60を、その電磁波漏出防止作用を示す長さ方向が導波路の長さ方向と一致するように設けている。   The millimeter wave band filter 20 shown in FIG. 1 employs the above-described study technique, and the first waveguide 21 is opposed to the inner wall of the first waveguide forming body 31 of the second waveguide 30 with a gap therebetween. A groove 60 for preventing electromagnetic wave leakage is formed on the upper and lower (longer side) outer walls close to the tip of the rectangular tube portion 21a so that the length direction showing the electromagnetic wave leakage preventing action coincides with the length direction of the waveguide. Provided.

つまり、電磁波漏出防止作用を示す長さp=1mm程度の溝60を、深さ0.2mm程度で形成している。このような向きに設けた場合であっても、溝60のハーフミラーに近い方のエッジから遠い方のエッジまで伝搬して戻ってくる電磁波の位相がλ/2変化して入出力が相殺する(漏出電磁波に対してインピーダンスが非常に高くなるチョーク効果を示す)ため、電磁波漏出効果が得られる。   That is, the groove 60 having a length p = 1 mm and showing an electromagnetic wave leakage preventing action is formed with a depth of about 0.2 mm. Even in such a case, the phase of the electromagnetic wave propagating back from the edge closer to the half mirror of the groove 60 to the far edge changes by λ / 2, and the input and output cancel each other. (A choke effect in which the impedance becomes very high with respect to the leaked electromagnetic wave is exhibited), so that an electromagnetic wave leakage effect is obtained.

この溝60による電磁波漏出防止効果は、前記検討モデルから10dB程度の減衰と予想されるが、図1の(a)、(b)に点線で示しているように溝60を導波路の長さ方向に沿って複数段(図1では2段示しているが導波管の重なる長さを延長して3段以上設けてもよい)並べることで、より大きな減衰量を得ることができる。   The electromagnetic wave leakage prevention effect by the groove 60 is expected to be about 10 dB attenuation from the above examination model. However, as shown by the dotted lines in FIGS. 1A and 1B, the groove 60 is the length of the waveguide. By arranging a plurality of stages along the direction (two stages are shown in FIG. 1, three or more stages may be provided by extending the overlapping length of the waveguides), a larger attenuation can be obtained.

また、ここでは、電磁波漏出防止効果が高い第1導波管21の角筒部21aの上下(長辺側)の外壁に溝60を設けているが、第1導波路形成体31の左右(短辺側)の内壁に対向する左右(短辺側)の外壁にも溝を設けることができる。   Further, here, the grooves 60 are provided on the upper and lower (longer side) outer walls of the rectangular tube portion 21a of the first waveguide 21 having a high electromagnetic wave leakage prevention effect. Grooves can also be provided on the left and right (short side) outer walls facing the inner wall on the short side.

このように、実施形態のミリ波体フィルタ20では、第1導波路形成体31の内壁に隙間を挟んで対向する第1導波管21の角筒部21aの外壁に、電磁波漏出作用を示す長さ、即ち、漏出対象の電磁波の波長の1/4相当の長さ方向が導波路の長さ方向と一致するように形成された溝60によりその隙間からの電磁波漏出を防止している。   Thus, in the millimeter wave body filter 20 of the embodiment, the electromagnetic wave leakage action is shown on the outer wall of the rectangular tube portion 21a of the first waveguide 21 facing the inner wall of the first waveguide forming body 31 with the gap therebetween. Leakage of electromagnetic waves from the gap is prevented by the groove 60 formed so that the length, that is, the length direction corresponding to ¼ of the wavelength of the electromagnetic wave to be leaked coincides with the length direction of the waveguide.

このため、従来装置のように、チョーク形成体を別個に用意する必要がなくなり、部品点数および作業工数を大幅に減少させることができ、部品点数や位置合わせ作業の増加によるコスト高を招くことなく、容易に製造でき、かつ電磁波漏出による性能低下のないミリ波帯フィルタを実現できる。   For this reason, unlike the conventional apparatus, it is not necessary to prepare a separate choke forming body, the number of parts and the number of work steps can be greatly reduced, and the cost is not increased due to an increase in the number of parts and alignment work. Therefore, it is possible to realize a millimeter-wave band filter that can be easily manufactured and that does not deteriorate in performance due to electromagnetic leakage.

また、ミラー間隔の変化に対して不要共振器長が不変となり、その距離をミラー間隔に対して十分小さくすることで、不要共振によるフィルタの共振特性の乱れを防止できる。   Further, the length of the unnecessary resonator does not change with respect to the change in the mirror interval, and by making the distance sufficiently small with respect to the mirror interval, it is possible to prevent disturbance of the resonance characteristics of the filter due to unnecessary resonance.

なお、第1導波管21の角筒部21aの外壁に設けた溝60の開口の大きさはほぼ1mm×導波管幅(2mm程度)と広く、深さは前記例で0.2mm程度と浅いため、長期に渡って電気的に安定な特性を確保するための金メッキ処理を行なう際に、容易にメッキ液を進入させることができる。   The opening of the groove 60 provided on the outer wall of the rectangular tube portion 21a of the first waveguide 21 is as wide as approximately 1 mm × waveguide width (approximately 2 mm), and the depth is approximately 0.2 mm in the above example. Therefore, the plating solution can be easily introduced when performing the gold plating process for securing electrically stable characteristics over a long period of time.

また、第1導波管21の本体をなす角筒部21aの肉厚としては、電磁波漏出防止作用を示す長さと無関係にその溝を形成できる程度の深さ分を見込めばよく、限られた口径の第1導波管であっても十分実現できる。   Further, the thickness of the rectangular tube portion 21a forming the main body of the first waveguide 21 is limited as long as the depth enough to allow the groove to be formed regardless of the length exhibiting the electromagnetic wave leakage preventing action is limited. Even a first waveguide having a diameter can be sufficiently realized.

なお、上記実施形態のミリ波帯フィルタ20では、第1導波管21を方形導波管とし、第2導波管30に内挿される角筒部21aの外壁に深さ0.2mm程度の溝60を形成しているため、最低限必要な肉厚として0.3mm程度が必要となり、この肉厚の増加により、第1導波管21の角筒部21aの内径と第2導波管30の第1導波路30aの内径との差が大きくなり、伝搬可能な下限周波数の差が大きくなり、実際にフィルタとして使用できる周波数帯域の下限側が制限されることになる。   In the millimeter waveband filter 20 of the above embodiment, the first waveguide 21 is a rectangular waveguide, and the outer wall of the rectangular tube portion 21a inserted into the second waveguide 30 has a depth of about 0.2 mm. Since the groove 60 is formed, a minimum required thickness of about 0.3 mm is required. Due to the increase in the thickness, the inner diameter of the rectangular tube portion 21a of the first waveguide 21 and the second waveguide are increased. The difference between the first waveguide 30a and the inner diameter of the first waveguide 30a increases, the difference in the lower limit frequency that can be propagated increases, and the lower limit side of the frequency band that can actually be used as a filter is limited.

ここで、第1導波管21の角筒部21aの内径を所望周波数帯の下限に合わせると、第1導波路30aの内径がその所望周波数帯の下限に対してかなり低い周波数に合ってしまい、別モードの伝搬が発生する恐れがある。逆に、第1導波路30aの内径を所望周波数帯の下限に合わせると、第1導波管21の角筒部21aの内径がその所望周波数帯の下限に対してかなり高い周波数に合ってしまい、所望周波数帯の伝搬が行なえない。   Here, when the inner diameter of the rectangular tube portion 21a of the first waveguide 21 is adjusted to the lower limit of the desired frequency band, the inner diameter of the first waveguide 30a matches a considerably lower frequency than the lower limit of the desired frequency band. There is a risk of propagation in another mode. On the other hand, when the inner diameter of the first waveguide 30a is adjusted to the lower limit of the desired frequency band, the inner diameter of the rectangular tube portion 21a of the first waveguide 21 matches a considerably higher frequency than the lower limit of the desired frequency band. , Propagation in the desired frequency band cannot be performed.

このような問題が発生する場合には、内側の第1導波管21として、小口径であっても低域まで通過特性が延びている導波管を用いればよい。   When such a problem occurs, a waveguide whose pass characteristics extend to a low frequency range may be used as the inner first waveguide 21 even with a small diameter.

例えば、導波管の長辺側の両内壁中央から互いに近づく方向に突出する突出部が長さ方向に連続して形成されていて、図7のように、導波路の断面形状が略H状となる所謂リッジ型導波管を用いることが考えられる。   For example, protrusions protruding in the direction approaching each other from the center of both inner walls on the long side of the waveguide are formed continuously in the length direction, and the cross-sectional shape of the waveguide is substantially H-shaped as shown in FIG. It is conceivable to use a so-called ridge-type waveguide.

このリッジ型導波管の場合、導波路22の中央部22aの幅w1と高さh1および両側部22b、22cの幅w2と高さh2を選ぶことで、標準の方形導波管の導波路の断面形状より小さい断面形状で、同等の周波数範囲の電磁波をTE10モードで伝搬できる。   In the case of this ridge-type waveguide, by selecting the width w1 and height h1 of the central portion 22a of the waveguide 22 and the width w2 and height h2 of the side portions 22b and 22c, the waveguide of a standard rectangular waveguide is selected. Electromagnetic waves in the same frequency range can be propagated in the TE10 mode with a smaller cross-sectional shape.

20……ミリ波帯フィルタ、21……第1導波管、22……導波路、30……第2導波管、30a……第1導波路、30b……第2導波路、31……第1導波路形成体、32……第2導波路形成体、40A、40B……電波ハーフミラー、50……支持機構、51……間隔可変手段、60……溝   20... Millimeter wave filter, 21... First waveguide, 22... Waveguide, 30... Second waveguide, 30 a... First waveguide, 30 b. ... 1st waveguide formation body, 32 ... 2nd waveguide formation body, 40A, 40B ... Radio wave half mirror, 50 ... Support mechanism, 51 ... Space variable means, 60 ... Groove

Claims (1)

ミリ波帯の所定周波数範囲の電磁波をTE10モードで伝搬させる口径の導波路(22)を有する第1導波管(21)と、
前記第1導波管の外径より大きく、且つ、前記所定周波数範囲の電磁波をTE10モードで伝搬させる口径を有し、前記第1導波管の一端側をその外周に隙間のある状態で受け入れる第1導波路(30a)と、該第1導波路より小さい口径の第2導波路(30b)とが同心に連続するように形成されている第2導波管(30)と、
前記所定周波数範囲の電磁波の一部を透過させ、一部を反射させる特性をもち、一方が前記第1導波管の前記一端側の導波路に固定され、他方が前記第2導波管の前記第1導波路と前記第2導波路の境界部に固定された一対の電波ハーフミラー(40A、40B)と、
前記一対の電波ハーフミラーの間隔が変化するように前記第1導波管を前記第2導波管に対して相対移動させて、前記所定周波数範囲の電磁波のうち前記一対の電波ハーフミラーの間隔で決まる共振周波数の電磁波を選択的に通過させる間隔可変手段(51)とを有し、
前記第2導波管が、
厚さ一定の板状部を有し、該板状部に前記第1導波路を形成する角穴が厚さ方向に貫通形成された第1導波路形成体(31)と、
厚さ一定の板状部を有し、該板状部に前記第2導波路を形成する角穴が厚さ方向に貫通形成された第2導波路形成体(32)とを含み、
前記第1導波路形成体と前記第2導波路形成体とが、前記角穴同士が同心に連続するように前記板状部同士を重ね合わせた状態で連結、分離可能に形成されたミリ波帯フィルタにおいて、
前記第2導波管の前記第1導波路の内壁に対向する前記第1導波管の外壁には、導波路の長手方向に沿った長さが漏出防止対象の電磁波の1/4波長相当となる溝(60)が形成され、該溝によって前記第1導波管の外壁と前記第2導波管の前記第1導波路の内壁との隙間からの電磁波漏出を防止することを特徴するミリ波帯フィルタ。
A first waveguide (21) having a waveguide (22) having a diameter for propagating electromagnetic waves in a predetermined frequency range in the millimeter wave band in a TE10 mode;
It has a diameter larger than the outer diameter of the first waveguide and propagates the electromagnetic wave in the predetermined frequency range in the TE10 mode, and accepts one end of the first waveguide with a gap on the outer periphery thereof. A second waveguide (30) formed such that the first waveguide (30a) and the second waveguide (30b) having a smaller diameter than the first waveguide are concentrically continuous;
The electromagnetic wave has a characteristic of transmitting a part of the electromagnetic wave in the predetermined frequency range and reflecting a part thereof, one of which is fixed to the waveguide on the one end side of the first waveguide and the other of the second waveguide. A pair of radio wave half mirrors (40A, 40B) fixed to the boundary between the first waveguide and the second waveguide;
The first waveguide is moved relative to the second waveguide so that the distance between the pair of radio wave half mirrors changes, and the distance between the pair of radio wave half mirrors among the electromagnetic waves in the predetermined frequency range. And an interval variable means (51) for selectively passing an electromagnetic wave having a resonance frequency determined by
The second waveguide is
A first waveguide forming body (31) having a plate-like portion having a constant thickness and having a square hole penetrating the plate-like portion forming the first waveguide in the thickness direction;
A second waveguide forming body (32) having a plate-like portion having a constant thickness, and a square hole forming the second waveguide is formed in the plate-like portion in the thickness direction;
The millimeter wave formed so that the first waveguide forming body and the second waveguide forming body can be connected and separated in a state where the plate-like portions are overlapped so that the square holes are concentrically continuous. In the band filter,
The outer wall of the first waveguide facing the inner wall of the first waveguide of the second waveguide has a length along the longitudinal direction of the waveguide corresponding to a quarter wavelength of the electromagnetic wave to be prevented from leaking. A groove (60) is formed, and the groove prevents leakage of electromagnetic waves from a gap between the outer wall of the first waveguide and the inner wall of the first waveguide of the second waveguide. Millimeter wave filter.
JP2014110217A 2014-05-28 2014-05-28 Millimeter wave band filter Active JP6315458B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2014110217A JP6315458B2 (en) 2014-05-28 2014-05-28 Millimeter wave band filter

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2014110217A JP6315458B2 (en) 2014-05-28 2014-05-28 Millimeter wave band filter

Publications (2)

Publication Number Publication Date
JP2015226207A true JP2015226207A (en) 2015-12-14
JP6315458B2 JP6315458B2 (en) 2018-04-25

Family

ID=54842694

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2014110217A Active JP6315458B2 (en) 2014-05-28 2014-05-28 Millimeter wave band filter

Country Status (1)

Country Link
JP (1) JP6315458B2 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114521305A (en) * 2019-10-18 2022-05-20 梅塔苏姆公司 Multilayer filter, arrangement and method for producing the same

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR958781A (en) * 1950-03-17
JP2013247381A (en) * 2012-05-23 2013-12-09 Anritsu Corp Millimeter wave band filter and manufacturing method thereof
JP2015201732A (en) * 2014-04-07 2015-11-12 アンリツ株式会社 Millimeter wave band filter

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR958781A (en) * 1950-03-17
JP2013247381A (en) * 2012-05-23 2013-12-09 Anritsu Corp Millimeter wave band filter and manufacturing method thereof
JP2015201732A (en) * 2014-04-07 2015-11-12 アンリツ株式会社 Millimeter wave band filter

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114521305A (en) * 2019-10-18 2022-05-20 梅塔苏姆公司 Multilayer filter, arrangement and method for producing the same
CN114521305B (en) * 2019-10-18 2023-07-18 梅塔苏姆公司 Multilayer filter, arrangement and method for producing the same

Also Published As

Publication number Publication date
JP6315458B2 (en) 2018-04-25

Similar Documents

Publication Publication Date Title
US9397378B2 (en) Waveguide-type image rejection filter and single-sideband receiver, frequency divider, and sideband-separating receiver using the same filter
JP5499080B2 (en) Millimeter wave band filter and manufacturing method thereof
JP4154535B2 (en) Twisted waveguide and radio equipment
KR101133743B1 (en) Probe and antenna
JP5442804B2 (en) Millimeter wave band filter
JP6315458B2 (en) Millimeter wave band filter
US20130135062A1 (en) Radio-wave half mirror for millimeter waveband and method of smoothing transmittance
JP5978180B2 (en) Millimeter wave filter and method for preventing leakage of electromagnetic wave
US8970321B2 (en) Millimeter waveband filter and method of increasing rejection band attenuation
JP6220705B2 (en) Millimeter wave band filter
JP2011176726A (en) Corner waveguide
JP6315451B2 (en) Millimeter wave band filter
JP2016092551A (en) Millimeter wave transmission line conversion structure
JP6209494B2 (en) Millimeter wave band filter
JP2016019016A (en) Millimeter wave band filter
US9385410B2 (en) Radio wave half mirror for millimeter wave band and method of flattening transmittance thereof
JP2015056721A (en) Millimeter wave band filter and wide area attenuation method for millimeter wave band
JP5781474B2 (en) Millimeter-wave band filter and resonance frequency variable method thereof
JP6220722B2 (en) Radio wave half mirror for millimeter wave band and method for flattening its transmission coefficient
JP2015133580A (en) plane transmission line waveguide converter
JP2002100903A (en) Dielectric line device and communication apparatus

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20160905

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20170829

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20171027

A02 Decision of refusal

Free format text: JAPANESE INTERMEDIATE CODE: A02

Effective date: 20171121

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20180220

RD03 Notification of appointment of power of attorney

Free format text: JAPANESE INTERMEDIATE CODE: A7423

Effective date: 20180222

RD04 Notification of resignation of power of attorney

Free format text: JAPANESE INTERMEDIATE CODE: A7424

Effective date: 20180223

A911 Transfer to examiner for re-examination before appeal (zenchi)

Free format text: JAPANESE INTERMEDIATE CODE: A911

Effective date: 20180227

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20180320

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20180320

R150 Certificate of patent or registration of utility model

Ref document number: 6315458

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R150

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250