CN115425422A - Terahertz quasi-optical sum-difference network based on medium beam splitting and polarization torsion grating - Google Patents

Terahertz quasi-optical sum-difference network based on medium beam splitting and polarization torsion grating Download PDF

Info

Publication number
CN115425422A
CN115425422A CN202210871633.4A CN202210871633A CN115425422A CN 115425422 A CN115425422 A CN 115425422A CN 202210871633 A CN202210871633 A CN 202210871633A CN 115425422 A CN115425422 A CN 115425422A
Authority
CN
China
Prior art keywords
polarization
plane mirror
reflected
grating
torsion
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.)
Pending
Application number
CN202210871633.4A
Other languages
Chinese (zh)
Inventor
胡标
徐凤强
朱国峰
李�浩
李天明
汪海洋
周翼鸿
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.)
University of Electronic Science and Technology of China
Original Assignee
University of Electronic Science and Technology of China
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 University of Electronic Science and Technology of China filed Critical University of Electronic Science and Technology of China
Priority to CN202210871633.4A priority Critical patent/CN115425422A/en
Publication of CN115425422A publication Critical patent/CN115425422A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q15/00—Devices for reflection, refraction, diffraction or polarisation of waves radiated from an antenna, e.g. quasi-optical devices
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q15/00—Devices for reflection, refraction, diffraction or polarisation of waves radiated from an antenna, e.g. quasi-optical devices
    • H01Q15/02—Refracting or diffracting devices, e.g. lens, prism
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q15/00—Devices for reflection, refraction, diffraction or polarisation of waves radiated from an antenna, e.g. quasi-optical devices
    • H01Q15/14—Reflecting surfaces; Equivalent structures

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)

Abstract

The invention discloses a terahertz quasi-optical sum-difference network based on medium beam splitting and polarization torsion grating, and belongs to the technical field of quasi-optical single pulse antennas. The polarization torsion grating polarization beam splitter comprises four input ports, six plane mirrors, three medium beam splitters and two polarization torsion gratings. The invention adopts two polarization torsion gratings to replace the plane mirror of the existing quasi-optical sum-difference network, thus solving the problem that the polarization direction of a single-polarization quasi-optical Gaussian beam changes before the single-polarization quasi-optical Gaussian beam passes through the front stage sum-difference comparator to reach the rear stage sum-difference comparator; in addition, the scheme of the invention also solves the problem that the existing dual-polarization 3dB beam splitter is difficult to realize wide-bandwidth beam splitting in two polarization directions, and the problem that the dual-polarization 3dB beam splitter and the grating 3dB beam splitter are high in processing precision, and effectively improves the sum-difference radiation characteristic of a sum-difference network. The method has the advantages of small loss, large bearing power, easy processing and capability of controlling the polarization direction of the wave beam.

Description

Terahertz quasi-optical sum-difference network based on medium beam splitting and polarization torsion grating
Technical Field
The invention belongs to the technical field of quasi-optical single-pulse antennas, and particularly relates to a dielectric beam splitting terahertz quasi-optical sum-difference network which is low in loss, large in bearing power and easy to process.
Background
The monopulse radar technology is used as a precise angle measurement technology, a sum-difference beam is realized by using a special sum-difference network, the aim of controlling pointing and tracking of the beam can be theoretically achieved in a single radar pulse, and the method is the most common mode of the current radar tracking system. The sum-difference network is used as the core of the monopulse radar technology, and the performance of the sum-difference network is often determined by the performance of the monopulse antenna. In microwave and millimeter wave frequency bands, single-pulse sum-difference networks based on waveguide, microstrip line, substrate integrated waveguide and other forms have more research results, and the transmission lines have problems of large loss, difficult processing and the like in terahertz frequency bands. The quasi-optical technology is a commonly used guided wave technology in an ultrahigh frequency and high power system, and quasi-optical Gaussian beams are propagated in a space bunching mode and naturally have the characteristic of low transmission loss, so that a solution idea is provided for a sum-difference network of a terahertz frequency band.
When the quasi-optical sum-difference network adopting the quasi-optical technology is used for realizing the positioning and tracking of a target by two dimensions, the problem that a single-polarization Gaussian beam is twisted by 90 degrees in the polarization direction before reaching a rear-stage sum-difference comparator through a front-stage sum-difference comparator needs to be solved, which means that a 3dB beam splitter in the quasi-optical sum-difference network needs to realize the beam splitting effect of the quasi-optical Gaussian beam in the two polarization directions. At present, a quasi-optical sum-difference network completed by using a dual-polarization 3dB beam splitter and a grating 3dB beam splitter is preliminarily verified. The dual-polarization 3dB beam splitter utilizes quartz and double-sided grid bars to realize beam splitting in two polarization directions, but is difficult to realize wide-bandwidth beam splitting effect in the two polarization directions, and the beam splitting effect is greatly influenced by processing errors; the grating 3dB beam splitter is composed of a series of metal wires which are arranged periodically, single polarization beam splitting effect can be achieved by selecting proper grating diameter and grating period, random polarization incidence can be controlled by changing the arrangement direction of the gratings, and the defect that the processing precision of the gratings is difficult to guarantee is overcome. Therefore, a better design solution to solve the above problems is urgently needed.
Disclosure of Invention
The invention aims to provide a terahertz quasi-optical sum-difference network based on a polarization torsion grating, which has the advantages of small loss, large bearing power, easiness in processing and capability of controlling the polarization direction of a wave beam, and meanwhile, the problem that the polarization direction of a single-polarization quasi-optical Gaussian wave beam changes before the single-polarization quasi-optical Gaussian wave beam passes through a front stage sum-difference comparator to reach a rear stage sum-difference comparator is solved, and the sum-difference radiation characteristic of the sum-difference network is effectively improved.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows:
a terahertz quasi-optical sum-difference network based on polarization torsion grating comprises: an input port D1, a azimuth difference port D2, a pitch difference port D3, a matching port D4, a plane mirror J1.1, a plane mirror J1.2, a plane mirror J2.1, a plane mirror J2.2, a plane mirror J3, a plane mirror J4, a medium beam splitter S1, a medium beam splitter S2, a medium beam splitter S3, a polarization torsion grating N1 and a polarization torsion grating N2;
the plane mirror J1.1, the plane mirror J1.2, the plane mirror J2.1, the plane mirror J2.2, the plane mirror J3 and the plane mirror J4 are all plane reflectors and are used for controlling the propagation direction of the wave beam;
the medium beam splitter S1, the medium beam splitter S2, and the medium beam splitter S3 are configured to equally divide the vertically polarized beam into a transmission beam and a reflection beam with equal amplitudes, and a phase of the transmission beam = a phase of the reflection beam +90 °;
the polarization torsion grating N1 and the polarization torsion grating N2 are used for controlling the propagation direction of the wave beam and changing the polarization direction of the Gaussian wave beam;
when a vertically polarized Gaussian beam A is incident from the summing port D1, reflected by the plane mirror J1.1 and then reaches the beam splitter S1, and is equally divided into the reflected beam A 1 And a transmitted beam A 2 At this time, the beam A is reflected 1 And the transmission beam A 2 Direction of polarizationAre all vertically polarized; reflected beam A 1 After being reflected by the polarization torsion grating N2, the polarization direction of the polarization torsion grating is changed into horizontal polarization, after being reflected by the plane mirror J1.2 and the plane mirror J2.1, the polarization direction of the polarization torsion grating is changed into vertical polarization again, and the polarization torsion grating reaches the dielectric beam splitter S3 and is equally divided into the reflected beam A 11 And a transmitted beam A 12 (ii) a Reflected beam A 11 The light is output after being reflected by a plane mirror J4 and a plane mirror J2.2 in sequence for two times; transmitted beam A 12 The light is reflected by a plane mirror J3 and then output; transmitted beam A 2 After being reflected by the polarization torsion grating N1, the polarization direction of the polarization torsion grating is changed into horizontal polarization, after being reflected by the plane mirror J2.1, the polarization direction of the polarization torsion grating is changed into vertical polarization, and the polarization direction is equally divided into the reflected wave beam A through the medium beam splitter S2 21 And a transmitted beam A 22 (ii) a Reflected beam A 21 The light is reflected by a plane mirror J4 and a plane mirror J2.2 in sequence and then output; transmitted beam A 22 The light is reflected by a plane mirror J3 and then output; and finally, four beams with the same amplitude and the same direction are obtained, and the sum effect of the sum and difference network is realized.
When the vertically polarized Gaussian beam B enters from the azimuth difference port D2 and reaches the beam splitter S1, the beam is equally divided into the reflected beam B 1 And a transmission beam B 2 At this time, the beam B is reflected 1 And the transmission beam B 2 The polarization directions are vertical polarization; reflected beam B 1 After being reflected by the polarization torsion grating N1, the polarization direction of the polarization torsion grating is changed into horizontal polarization, after being reflected by the plane mirror J2.1, the polarization direction of the polarization torsion grating is changed into vertical polarization, and the polarization direction is equally divided into the reflected wave beam B by the medium beam splitter S2 11 And a transmission beam B 12 (ii) a Reflected beam B 11 The light is output after being reflected by a plane mirror J4 and a plane mirror J2.2 in sequence for two times; transmitted beam B 12 The light is reflected by a plane mirror J3 and then output; transmitted beam B 2 After being reflected by the polarization torsion grating N2, the polarization direction of the polarization torsion grating is changed into horizontal polarization, after being reflected by the plane mirror J1.2 and the plane mirror J2.1, the polarization direction of the polarization torsion grating is changed into vertical polarization again, and the polarization torsion grating reaches the dielectric beam splitter S2 and is equally divided into the reflected beams B 21 And a transmission beam B 22 (ii) a Reflected beam B 21 The light is reflected by a plane mirror J4 and a plane mirror J2.2 in sequence and then output; transmitted beam A 22 The light is reflected by a plane mirror J3 and then output; finally, the product is processedFour beams with equal amplitude and 180-degree phase difference of azimuth planes are obtained, and the difference effect of the sum-difference network on the azimuth plane is realized.
When the vertically polarized Gaussian beam C is incident from the pitch difference port D3, is reflected by the plane mirror J1.1, reaches the beam splitter S1 and is equally divided into the reflected beam C 1 And a transmitted beam C 2 At this time, the beam C is reflected 1 And the transmitted beam C 2 The polarization directions are vertical polarization; reflected beam C 1 After being reflected by the polarization torsion grating N2, the polarization direction of the polarization torsion grating is changed into horizontal polarization, the polarization is vertical to the incident plane of the incident medium beam splitter S2, and the polarization torsion grating is equally divided into reflected beams C by the medium beam splitter S2 11 And a transmitted beam C 12 (ii) a Reflected beam C 11 The light is reflected by a plane mirror J3 and then output; transmitted beam C 12 The light is output after being reflected by a plane mirror J4 and a plane mirror J2.2 in sequence for two times; transmitted beam C 2 After being reflected by the polarization torsion grating N1, the polarization direction of the polarization torsion grating is changed into vertical polarization, and the polarization torsion grating reaches the dielectric beam splitter S3 and is equally divided into reflected beams C 21 And a transmitted beam C 22 (ii) a Reflected beam C 21 The light is reflected by a plane mirror J3 and then output; transmitted beam C 22 The light is reflected by a plane mirror J4 and a plane mirror J2.2 in sequence and then output; and finally, four beams with the same amplitude and 180-degree phase difference of the pitching surfaces are obtained, and the difference effect of the sum and difference network on the pitching surfaces is realized.
Further, the plane mirror J1.1, the beam splitter S1 and the polarization torsion grating N1 are sequentially arranged and are parallel to each other, and an included angle of 45 degrees is formed between the plane mirror J1.1 and the input port; the plane mirror J1.2 is arranged in parallel with the polarization torsion N2; the plane mirror J2.1, the medium beam splitter S2, the medium beam splitter S3 and the plane mirror J3 are parallel to each other, and the medium beam splitter S2 and the medium beam splitter S3 are arranged between the plane mirror J2.1 and the plane mirror J3 in parallel; the plane mirror J2.2 and the plane mirror J4 are arranged in parallel; the included angle between the plane mirror J1.1 and the plane mirror J1.2, the included angle between the medium beam splitter S1 and the polarization torsion grating N2, the included angle between the plane mirror J2.1 and the plane mirror J2.2, the included angle between the medium beam splitter S2 and the plane mirror J4 and the included angle between the medium beam splitter S3 and the plane mirror J4 are all 90 degrees.
Further, the beam is reflected 90 ° in both the quasi-optical and the difference network.
Further, the polarization torsion grating N1 is formed by periodically arranging a plurality of metal cylinders.
Further, the material of the medium beam splitter is quartz, and the thickness d of the medium beam splitter meets the condition:
Figure BDA0003761063380000031
wherein λ 0 Is the operating wavelength,. Epsilon r Is the dielectric constant of the medium, theta i Is the angle of incidence.
Further, the distances between the plane mirror J1.1 and the medium beam splitter S1, between the medium beam splitter S1 and the polarization torsion grating N2, between the polarization torsion grating N2 and the plane mirror J1.2, between the plane mirror J2.1 and the medium beam splitter S2/S3, between the medium beam splitter S2/S3 and the plane mirror J4, and between the plane mirror J4 and the plane mirror J2.2 are all h; the distance between the dielectric beam splitter S1 and the polarization torsion grating N1 and the distance between the dielectric beam splitter S2/S3 and the plane mirror J3 are L = h-lambda 0 /4。
To achieve the sum effect of the quasi-optical sum and difference network, when the beam a is incident from the sum input port D1 and passes through the beam splitter, the beam is divided into the transmission beam a 2 And a reflected beam A 1 At this time, the transmitted beam A 2 And the reflected beam A 1 Are equal in amplitude, the transmitted beam a 2 Phase = reflected beam a 1 Phase +90 deg.. Since the distance between the plane mirror J1.1 and the beam splitter S1 is h, the distance L between the polarization torsion grating N1 and the beam splitter S1 is L = h- λ 0 /4, i.e. transmission beam A 2 The phase at the second output port will be advanced by 90 deg., at which time the reflected beam a will pass through the post-stage collimating sum-difference comparator before passing through the post-stage collimating sum-difference comparator 1 And the transmission beam A 2 The phases will be equal and the amplitudes will be equal, and similarly, the two beams will reflect the beam a after passing through the post-stage sum and difference comparator 1 And the transmission beam A 2 The beams are divided into two equal-amplitude same-direction beams by the beam splitters S2 and S3, and four equal-amplitude same-direction beams are finally radiated.
To achieve the azimuth difference effect of the quasi-optical sum and difference network, when the beam B is incident from the azimuth difference input port D2 and passes through the beam splitter, the beam is divided into the transmission beam B 2 And reflected beam B 1 At this time, the beam B is transmitted 2 And reflected beam B 1 Are equal in amplitude, the transmitted beam B 2 Phase = reflected beam B 1 Phase +90 deg.. Since the distance between the plane mirror J1.1 and the beam splitter S1 is h, the distance L between the polarization torsion grating N1 and the beam splitter S1 is L = h- λ 0 /4, i.e. transmission beam B 2 The phase at the second output port will be advanced by 90 deg., in which case the beam B is reflected before passing through the post-stage collimating sum-difference comparator 1 And the transmission beam B 2 The amplitudes are equal, the phase difference is 180 degrees, and the two wave beams reflect a wave beam B after passing through a post-stage sum-difference comparator 1 And the transmission beam B 2 The beams are divided into two equal-amplitude and same-direction beams through the beam splitters S2 and S3, and four beams with equal amplitude and 180-degree phase difference on the azimuth plane are finally radiated.
To achieve the elevation difference effect of the sum and difference network, when a beam C is incident from the elevation difference input port D3 and passes through the beam splitter, the beam is divided into a transmission beam C 2 And reflected beam C 1 At this time, the beam C is transmitted 2 And reflected beam C 1 Are equal in amplitude, transmit beam C 2 Phase = reflected beam C 1 Phase +90 deg.. Since the distance between the plane mirror J1.1 and the beam splitter S1 is h, the distance L between the polarization torsion grating N1 and the beam splitter S1 is L = h- λ 0 /4, i.e. transmission beam C 2 The phase of the second output port will be advanced by 90 deg. when the reflected beam C is passed through the post-stage sum-difference comparator 1 And the transmitted beam C 2 The phases will be equal and the amplitudes will be equal, and similarly, the two beams pass through the post-stage sum and difference comparator and the beam C is reflected 1 And the transmitted beam C 2 The beams are divided into two beams with equal amplitude and 180-degree phase difference through the beam splitters S2 and S3, and four beams with equal amplitude and 180-degree phase difference on the pitching surface are finally radiated.
The scheme of the invention adopts two polarization torsion gratings to replace the plane mirror of the original quasi-optical sum-difference network, thus solving the problem that the polarization direction of a single-polarization quasi-optical Gaussian beam changes before the single-polarization quasi-optical Gaussian beam passes through the front stage sum-difference comparator to reach the rear stage sum-difference comparator; in addition, the scheme of the invention also solves the problem that the existing dual-polarization 3dB beam splitter is difficult to realize wide-bandwidth beam splitting in two polarization directions, and also solves the problem of high processing precision of the dual-polarization 3dB beam splitter and the grating 3dB beam splitter.
Drawings
Fig. 1 is a schematic structural diagram of a terahertz quasi-optical sum-difference network based on a polarization torsion grating.
Fig. 2 is a schematic diagram of propagation paths of a gaussian beam incident from a sum port in a quasi-optical sum-difference network, where (a) is a diagram of actual propagation paths, and (b) is a diagram of propagation paths.
Fig. 3 is a schematic diagram of propagation paths of a gaussian beam incident from an azimuth difference port in a quasi-optical sum-difference network.
Fig. 4 is a schematic diagram of the propagation path of a gaussian beam incident from a pitch difference port in a quasi-optical sum-difference network.
Fig. 5 is a schematic diagram of a structure of a polarization torsion grating.
The reference numbers indicate: 1. and input ports D1,2 azimuth difference ports D2,3 elevation difference ports D3,4 matching ports D4,5 plane mirrors J1.1,6 plane mirrors J1.2,7 plane mirrors J2.1,8 plane mirrors J2.2,9 plane mirrors J3, 10 plane mirrors J4, 11 medium beam splitters S1, 12 medium beam splitters S2, 13 medium beam splitters S3, 14 polarization torsion gratings N1, 15 polarization torsion gratings N2.
Detailed Description
The technical scheme of the invention is further illustrated by the following embodiments in combination with the attached drawings.
Fig. 1 is a schematic structural diagram of a terahertz quasi-optical sum-difference network based on a polarization torsion grating, as shown in fig. 1, the quasi-optical sum-difference network includes: and an input port D1, a azimuth difference port D2, a pitch difference port D3, a matching port D4, a plane mirror J1.1, a plane mirror J1.2, a plane mirror J2.1, a plane mirror J2.2, a plane mirror J3, a plane mirror J4, a medium beam splitter S1, a medium beam splitter S2, a medium beam splitter S3, a polarization torsion grating N1 and a polarization torsion grating N2. Wherein, the plane mirror J1.1, the plane mirror J1.2, the plane mirror J2.1, the plane mirror J2.2, the plane mirror J3 and the plane mirror J4 are all plane reflecting mirrors; the dielectric beam splitter is made of quartz, the dielectric constant of the dielectric beam splitter is 3.78, and the thickness of the dielectric beam splitter is 0.15mm; the structure of the polarization torsion grating is shown in fig. 5 and is formed by periodically arranging metal cylinders, wherein the diameter a of each metal cylinder is 0.2mm, and the grating interval g is 0.275mm; the operating frequency of the quasi-optical sum and difference network is 340GHz.
The incident Gaussian beam is generated by a Gaussian feed horn, the working frequency of the Gaussian beam is 340GHz, and the radius of the beam waist of the Gaussian beam is 4.5mm.
The plane mirror J1.1, the beam splitter S1 and the polarization torsion grating N1 are sequentially arranged and are parallel to each other, and an included angle of 45 degrees is formed between the plane mirror J1.1 and the input port; the plane mirror J1.2 is arranged in parallel with the polarization torsion N2; the plane mirror J2.1, the medium beam splitter S2, the medium beam splitter S3 and the plane mirror J3 are parallel to each other, and the medium beam splitter S2 and the medium beam splitter S3 are arranged between the plane mirror J2.1 and the plane mirror J3 side by side; the plane mirror J2.2 and the plane mirror J4 are arranged in parallel; the included angle between the plane mirror J1.1 and the plane mirror J1.2, the included angle between the medium beam splitter S1 and the polarization torsion grating N2, the included angle between the plane mirror J2.1 and the plane mirror J2.2, the included angle between the medium beam splitter S2 and the plane mirror J4, and the included angle between the medium beam splitter S3 and the plane mirror J4 are all 90 degrees.
The distance h between the plane mirror J1.1 and the medium beam splitter S1, between the medium beam splitter S1 and the polarization torsion grating N2, between the polarization torsion grating N2 and the plane mirror J1.2, between the plane mirror J2.1 and the medium beam splitter S2/S3, between the medium beam splitter S2/S3 and the plane mirror J4, and between the plane mirror J4 and the plane mirror J2.2 are all 25mm; the distance L between the dielectric beam splitter S1 and the polarization torsion grating N1 and between the dielectric beam splitter S2/S3 and the plane mirror J3 is 24.78mm, namely, the distance is reduced by lambda relative to the former 0 /4。
To achieve the sum effect of the quasi-optical sum and difference network, when the beam a is incident from the sum input port D1 and passes through the beam splitter, the beam is divided into the transmission beam a 2 And a reflected beam A 1 At this time, the beam A is transmitted 2 And the reflected beam A 1 Are equal in amplitude, the transmitted beam a 2 Phase = reflected beam A1 phase +90 °. Since the distance between the plane mirror J1.1 and the beam splitter S1 is h, the distance L between the polarization torsion grating N1 and the beam splitter S1 is L = h- λ 0 /4, i.e. transmission beam A 2 The phase of the second output port is advanced by 90 DEG, and the reflected beam passes through the quasi-optical sum-difference comparatorA 1 And the transmission beam A 2 The phases will be equal and the amplitudes will be equal, and similarly, the two beams will reflect the beam a after passing through the post-stage sum and difference comparator 1 And the transmission beam A 2 The beams are divided into two equal-amplitude same-direction beams by the beam splitters S2 and S3, and four equal-amplitude same-direction beams are finally radiated.
To achieve the azimuth difference effect of the quasi-optical sum and difference network, when the beam B is incident from the azimuth difference input port D2 and passes through the beam splitter, the beam is divided into the transmission beam B 2 And reflected beam B 1 At this time, the beam B is transmitted 2 And reflected beam B 1 Are equal in amplitude, transmit beam B 2 Phase = reflected beam B 1 Phase +90 deg.. Since the distance between the plane mirror J1.1 and the beam splitter S1 is h, the distance L between the polarization torsion grating N1 and the beam splitter S1 is L = h- λ 0 /4, i.e. transmission beam B 2 The phase at the second output port will be advanced by 90 deg., in which case the beam B is reflected before passing through the post-stage collimating sum-difference comparator 1 And the transmission beam B 2 The amplitudes are equal, the phase difference is 180 degrees, and the two wave beams reflect a wave beam B after passing through a post-stage sum-difference comparator 1 And the transmission beam B 2 The beams are divided into two equal-amplitude and same-direction beams through the beam splitters S2 and S3, and four beams with equal amplitude and 180-degree phase difference on the azimuth plane are finally radiated.
To achieve the elevation difference effect of the quasi-optical sum difference network, when the beam C is incident from the elevation difference input port D3 and passes through the beam splitter, the beam is divided into the transmission beam C 2 And a reflected beam C 1 At this time, the transmitted beam C 2 And reflected beam C 1 Are equal in amplitude, the transmitted beam C 2 Phase = reflected beam C 1 Phase +90 deg.. Since the distance between the plane mirror J1.1 and the beam splitter S1 is h, the distance L between the polarization torsion grating N1 and the beam splitter S1 is L = h- λ 0 /4, i.e. transmitted beam C 2 The phase of the second output port will be advanced by 90 deg. when the reflected beam C is passed through the post-stage sum-difference comparator 1 And the transmitted beam C 2 The phases will be equal and the amplitudes will be equal, and, similarly, after the two beams pass through the final stage sum and difference comparator,reflected beam C1 and transmitted beam C 2 The beams are divided into two beams with equal amplitude and 180-degree phase difference through the beam splitters S2 and S3, and four beams with equal amplitude and 180-degree phase difference on the pitching surface are finally radiated.
The scheme of the invention adopts two polarization torsion gratings to replace the plane mirror of the original quasi-optical sum-difference network, thus solving the problem that the polarization direction of a single-polarization quasi-optical Gaussian beam changes before the single-polarization quasi-optical Gaussian beam passes through a front stage sum-difference comparator to reach a rear stage sum-difference comparator; in addition, the scheme of the invention solves the problem that the existing dual-polarization 3dB beam splitter is difficult to realize wide-bandwidth beam splitting in two polarization directions, and also solves the problem of high processing precision of the dual-polarization 3dB beam splitter and the grating 3dB beam splitter.

Claims (6)

1. A terahertz quasi-optical sum-difference network based on polarization torsion grating is characterized by comprising: an input port D1, a azimuth difference port D2, a pitch difference port D3, a matching port D4, a plane mirror J1.1, a plane mirror J1.2, a plane mirror J2.1, a plane mirror J2.2, a plane mirror J3, a plane mirror J4, a medium beam splitter S1, a medium beam splitter S2, a medium beam splitter S3, a polarization torsion grating N1 and a polarization torsion grating N2;
the plane mirror J1.1, the plane mirror J1.2, the plane mirror J2.1, the plane mirror J2.2, the plane mirror J3 and the plane mirror J4 are all plane reflectors and are used for controlling the propagation direction of the wave beam;
the medium beam splitter S1, the medium beam splitter S2 and the medium beam splitter S3 are used for equally dividing the vertically polarized beam into a transmission beam and a reflection beam with equal amplitude, and the phase of the transmission beam = the phase of the reflection beam +90 degrees;
the polarization torsion grating N1 and the polarization torsion grating N2 are used for controlling the propagation direction of the wave beam and changing the polarization direction of the Gaussian wave beam;
when a vertically polarized Gaussian beam A is incident from the summing port D1, reflected by the plane mirror J1.1 and then reaches the beam splitter S1, and is equally divided into the reflected beam A 1 And a transmitted beam A 2 At this time, the beam A is reflected 1 And the transmission beam A 2 The polarization directions are vertical polarization; reflected beam A 1 After being reflected by the polarization torsion grating N2The polarization direction of the beam is changed into horizontal polarization, and after the beam is reflected by a plane mirror J1.2 and a plane mirror J2.1, the polarization direction of the beam is changed into vertical polarization again, and the beam reaches a dielectric beam splitter S3 and is equally divided into a reflected beam A 11 And a transmitted beam A 12 (ii) a Reflected beam A 11 The light is output after being reflected by a plane mirror J4 and a plane mirror J2.2 in sequence for two times; transmitted beam A 12 The light is reflected by a plane mirror J3 and then output; transmitted beam A 2 After being reflected by the polarization torsion grating N1, the polarization direction of the polarization torsion grating is changed into horizontal polarization, after being reflected by the plane mirror J2.1, the polarization direction of the polarization torsion grating is changed into vertical polarization, and the polarization direction is equally divided into the reflected wave beam A through the medium beam splitter S2 21 And a transmitted beam A 22 (ii) a Reflected beam A 21 The light is reflected by a plane mirror J4 and a plane mirror J2.2 in sequence and then output; transmitted beam A 22 The light is reflected by a plane mirror J3 and then output; finally, four beams with the same amplitude and the same direction are obtained, and the sum effect of the sum and difference network is realized;
when the vertically polarized Gaussian beam B enters from the azimuth difference port D2 and reaches the beam splitter S1, the beam is equally divided into the reflected beam B 1 And a transmission beam B 2 At this time, the beam B is reflected 1 And the transmission beam B 2 The polarization directions are vertical polarization; reflected beam B 1 After being reflected by the polarization torsion grating N1, the polarization direction of the polarization torsion grating is changed into horizontal polarization, after being reflected by the plane mirror J2.1, the polarization direction of the polarization torsion grating is changed into vertical polarization, and the polarization direction is equally divided into the reflected wave beam B by the medium beam splitter S2 11 And a transmission beam B 12 (ii) a Reflected beam B 11 The light is output after being reflected by a plane mirror J4 and a plane mirror J2.2 in sequence for two times; transmitted beam B 12 The light is reflected by a plane mirror J3 and then output; transmitted beam B 2 After being reflected by the polarization torsion grating N2, the polarization direction of the polarization torsion grating is changed into horizontal polarization, after being reflected by the plane mirror J1.2 and the plane mirror J2.1, the polarization direction of the polarization torsion grating is changed into vertical polarization again, and the polarization torsion grating reaches the dielectric beam splitter S2 and is equally divided into the reflected beams B 21 And a transmission beam B 22 (ii) a Reflected beam B 21 The light is reflected by a plane mirror J4 and a plane mirror J2.2 in sequence and then output; transmitted beam A 22 The light is reflected by a plane mirror J3 and then output; finally, four beams with equal amplitude and 180-degree phase difference of azimuth planes are obtained, and the sum-difference network is realized in the squarePoor effect on bit plane;
when the vertically polarized Gaussian beam C is incident from the pitch difference port D3, is reflected by the plane mirror J1.1, reaches the beam splitter S1 and is equally divided into the reflected beam C 1 And a transmitted beam C 2 At this time, the beam C is reflected 1 And the transmitted beam C 2 The polarization directions are vertical polarization; reflected beam C 1 After being reflected by the polarization torsion grating N2, the polarization direction of the polarization torsion grating is changed into horizontal polarization, the polarization is vertical to the incident plane of the incident medium beam splitter S2, and the polarization torsion grating is equally divided into reflected beams C by the medium beam splitter S2 11 And a transmitted beam C 12 (ii) a Reflected beam C 11 The light is reflected by a plane mirror J3 and then output; transmitted beam C 12 The light is output after being reflected by a plane mirror J4 and a plane mirror J2.2 in sequence for two times; transmitted beam C 2 After being reflected by the polarization torsion grating N1, the polarization direction of the polarization torsion grating is changed into vertical polarization, and the polarization torsion grating reaches the dielectric beam splitter S3 and is equally divided into reflected beams C 21 And a transmitted beam C 22 (ii) a Reflected beam C 21 The light is reflected by a plane mirror J3 and then output; transmitted beam C 22 The light is reflected by a plane mirror J4 and a plane mirror J2.2 in sequence and then output; and finally, four beams with the same amplitude and 180-degree phase difference of the pitching surfaces are obtained, and the difference effect of the sum and difference network on the pitching surfaces is realized.
2. The terahertz quasi-optical sum-difference network based on the polarization torsion grating as claimed in claim 1, wherein the plane mirror J1.1, the beam splitter S1 and the polarization torsion grating N1 are sequentially arranged and parallel to each other, and form an included angle of 45 ° with the input port; the plane mirror J1.2 is arranged in parallel with the polarization torsion N2; the plane mirror J2.1, the medium beam splitter S2, the medium beam splitter S3 and the plane mirror J3 are parallel to each other, and the medium beam splitter S2 and the medium beam splitter S3 are arranged between the plane mirror J2.1 and the plane mirror J3 in parallel; the plane mirror J2.2 and the plane mirror J4 are arranged in parallel; the included angle between the plane mirror J1.1 and the plane mirror J1.2, the included angle between the medium beam splitter S1 and the polarization torsion grating N2, the included angle between the plane mirror J2.1 and the plane mirror J2.2, the included angle between the medium beam splitter S2 and the plane mirror J4 and the included angle between the medium beam splitter S3 and the plane mirror J4 are all 90 degrees.
3. The terahertz quasi-optical sum-difference network based on the polarization torsion grating as claimed in claim 2, wherein the distances between the plane mirror J1.1 and the dielectric beam splitter S1, between the dielectric beam splitter S1 and the polarization torsion grating N2, between the polarization torsion grating N2 and the plane mirror J1.2, between the plane mirror J2.1 and the dielectric beam splitter S2/S3, between the dielectric beam splitter S2/S3 and the plane mirror J4, and between the plane mirror J4 and the plane mirror J2.2 are all h; the distance between the dielectric beam splitter S1 and the polarization torsion grating N1 and the distance between the dielectric beam splitter S2/S3 and the plane mirror J3 are L = h-lambda 0 /4。
4. The terahertz quasi-optical sum-difference network based on the polarization torsion grating is characterized in that the reflection of the wave beam in the quasi-optical sum-difference network is 90 degrees.
5. The terahertz quasi-optical sum-difference network based on the polarization torsion grating as claimed in claim 4, wherein the polarization torsion grating N1 is composed of a plurality of metal cylinders which are periodically arranged.
6. The terahertz quasi-optical sum-difference network based on the polarization torsion grating as claimed in claim 4, wherein the material of the dielectric beam splitter is quartz, and the thickness d thereof satisfies the condition:
Figure FDA0003761063370000021
wherein λ 0 Is the operating wavelength,. Epsilon r Is the dielectric constant of the medium, theta i Is the angle of incidence.
CN202210871633.4A 2022-07-22 2022-07-22 Terahertz quasi-optical sum-difference network based on medium beam splitting and polarization torsion grating Pending CN115425422A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210871633.4A CN115425422A (en) 2022-07-22 2022-07-22 Terahertz quasi-optical sum-difference network based on medium beam splitting and polarization torsion grating

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210871633.4A CN115425422A (en) 2022-07-22 2022-07-22 Terahertz quasi-optical sum-difference network based on medium beam splitting and polarization torsion grating

Publications (1)

Publication Number Publication Date
CN115425422A true CN115425422A (en) 2022-12-02

Family

ID=84196555

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210871633.4A Pending CN115425422A (en) 2022-07-22 2022-07-22 Terahertz quasi-optical sum-difference network based on medium beam splitting and polarization torsion grating

Country Status (1)

Country Link
CN (1) CN115425422A (en)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2019065975A1 (en) * 2017-09-28 2019-04-04 国立研究開発法人産業技術総合研究所 Circularl polarization-type polarization diversity element, scanning element using same, and lidar
CN113206387A (en) * 2021-04-22 2021-08-03 电子科技大学 Wide-bandwidth terahertz quasi-optical sum-difference comparator

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2019065975A1 (en) * 2017-09-28 2019-04-04 国立研究開発法人産業技術総合研究所 Circularl polarization-type polarization diversity element, scanning element using same, and lidar
CN113206387A (en) * 2021-04-22 2021-08-03 电子科技大学 Wide-bandwidth terahertz quasi-optical sum-difference comparator

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
HUAN GUO等: ""A Low-Loss and Dual-Polarized Wideband Quasi-Optical Comparator at Terahertz Frequencies"", 《IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS》, vol. 21, no. 07, 28 April 2022 (2022-04-28) *
王龙: ""毫米波准光空间波束功率合成技术研究"", 《中国知网优秀硕士论文全文库信息科技辑》, no. 05, 15 May 2019 (2019-05-15) *

Similar Documents

Publication Publication Date Title
CN110571531B (en) Multi-beam phased array antenna based on parabolic cylinder reflective array
Ettorre et al. Multi-beam multi-layer leaky-wave SIW pillbox antenna for millimeter-wave applications
Wang et al. Spatial multi-polarized leaky-wave antenna based on spoof surface plasmon polaritons
Legay et al. Multiple beam antenna based on a parallel plate waveguide continuous delay lens beamformer
CN102694231A (en) Novel high-power microwave antenna
US4491845A (en) Wide angle phased array dome lens antenna with a reflection/transmission switch
CN113206387B (en) Wide-bandwidth terahertz frequency band quasi-optical sum-difference comparator
Yin et al. Frequency scanning single-ridge serpentine dual-slot-waveguide array antenna
CN115425422A (en) Terahertz quasi-optical sum-difference network based on medium beam splitting and polarization torsion grating
Bartolomei et al. Circularly polarized parallel plate waveguide multiple-beam lens-like antenna for satcom applications
Nahar et al. Wideband antenna array beam steering with free-space optical true-time delay engine
US9876284B2 (en) Multibeam source
Cruickshank et al. Reducing standing waves in quasi-optical systems by optimal feedhorn design
He et al. 140 GHz High-efficiency Low-profile Reflectarray Antenna Using Heterogeneous Design Strategy
Castillo-Tapia et al. Modulated geodesic lens antenna array
Xu et al. Leaky-wave radiation from periodically modulated spoof surface plasmon polaritons
Xie et al. RCS and side lobe reduction for OAM vortex beam of antenna array using ebg structures
CN112909513B (en) Dual-polarized waveguide slot array antenna on annular disc and combined antenna
Jiang et al. A Circularly Polarized Antenna with Low Sidelobe Based on Spoof Surface Plasmon Polariton
Song et al. High-efficiency multi-beam GRIN lens with 2-D wide-angle coverages
CN111653857B (en) High-power capacity quasi-optical dual-frequency synthesizer based on optical interference principle
Saifullah et al. Dynamic Control of Electromagnetic Waves by 2-Bit Programmable Metasurface in Dual-Band
CN117289476A (en) Circularly polarized transceiving isolation terahertz quasi-light sum and difference comparator
Sidorov et al. Shaping of Flat-Topped Element Patterns in Phased Arrays of Coupled Multimode Waveguides of Hexagonal Cross Section
Li et al. Research on a New Compound Antenna for Millimeter Wave/infrared Seeker

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination