WO2016161795A1

WO2016161795A1 - Filter

Info

Publication number: WO2016161795A1
Application number: PCT/CN2015/092732
Authority: WO
Inventors: 蔡凌云
Original assignee: 中兴通讯股份有限公司
Priority date: 2015-04-08
Filing date: 2015-10-23
Publication date: 2016-10-13
Also published as: CN106159393A

Abstract

A filter. A four-pass band filter is designed by cascading two one-half wavelength resonators, a loaded ring-shaped quarter wavelength resonator and a three-quarter wavelength resonator, cascade connection of the two coupling incentive one-half wavelength resonators being adjustable, and two loaded quarter wavelength interdigital coupling resonators; and the four-pass band filter is high in out-of-band rejection ability, simple in structure, small in size, convenient in integration with a circuit board of a mobile phone and a CPE, low in cost, easy in batch production, etc., and is applicable to multiple terminal systems. The filter has a better out-of-band rejection ability, and can meet the characteristics of miniaturization and pass band controllability.

Description

一种滤波器a filter

技术领域Technical field

本文属于但不限于无线通信技术领域，具体涉及一种滤波器。This document belongs to but not limited to the field of wireless communication technologies, and in particular relates to a filter.

背景技术Background technique

在一个通信***中，有源电路的输入输出端之间普遍存在各级滤波器，各滤波器有各自不同的功能，它的性能好坏直接关系整个***的通信质量。滤波器的功能包括减小来自天线端的本机振荡器的功率泄漏；削弱同时存在的不同通信***间的干扰；避免由于发射端输出信号泄漏而使接收器前端饱和；滤除如镜频一类的干扰信号。随着无线通信***的快速发展，对低插损、陡峭的上升下降沿衰减、平坦的群时延、小型化的多通带滤波器提出更高的要求。In a communication system, there are various levels of filters between the input and output of the active circuit. Each filter has its own different function, and its performance is directly related to the communication quality of the whole system. The function of the filter includes reducing the power leakage of the local oscillator from the antenna end; weakening the interference between different communication systems at the same time; avoiding saturation of the receiver front end due to leakage of the output signal of the transmitting end; filtering out such as image frequency Interference signal. With the rapid development of wireless communication systems, higher requirements are placed on low insertion loss, steep rise and fall edge attenuation, flat group delay, and miniaturized multi-passband filters.

通过增加滤波器阶数可提高滤波器的频率选择性但会导致滤波器体积增大，插损增加；通过在阻带引入对称的传输零点可实现滤波器高选择性，又会使得电路复杂、调试难度大。By increasing the filter order, the frequency selectivity of the filter can be increased, but the filter volume is increased and the insertion loss is increased. By introducing a symmetric transmission zero point in the stop band, the filter can be highly selective, and the circuit can be complicated. The debugging is difficult.

近年来，滤波器的研究在不断地取得新进展，微型封装、性能好、低成本、易于安装使用的滤波器，在无线终端通信中一直是重点。随着多频段、多标准的无线通信技术的发展，相邻频段的频率选择干扰，这就需要让有用的信号通过，对干扰信号进行抑制以提高***的性能。因此，如何设计性能优越的多通带滤波器就显得非常必要。相关技术中实现多通带滤波器的常用方法有很多种，包括：In recent years, research on filters has been continuously making new progress. Micro-packages, good performance, low cost, and easy to install and use filters have always been the focus of wireless terminal communication. With the development of multi-band, multi-standard wireless communication technologies, the frequency of adjacent frequency bands is selected to interfere, which requires the use of useful signals to suppress the interference signals to improve system performance. Therefore, how to design a multi-passband filter with superior performance is very necessary. There are many common methods for implementing multi-passband filters in the related art, including:

使用四个单通带滤波器分别对信号进行处理，选出对应的频段信号；The signals are processed by using four single-passband filters to select corresponding frequency band signals;

在一个通带的滤波器基础上加入内嵌带阻单元：使用两阶或三阶的阶梯阻抗谐振器来设计带阻滤波器；Adding an in-line band-stop unit to a passband filter: designing a band-stop filter using a two- or third-order stepped-impedance resonator;

使用复合左/右手材料传输线代替传统的微带传输线；Replace the traditional microstrip transmission line with a composite left/right hand material transmission line;

使用嵌线、马刺线和常规微带线三种平面结构获得双阻带响应。 The double stopband response is obtained using three planar structures of ruled lines, spur lines, and conventional microstrip lines.

上述各种方法主要缺陷是集成度不够，频率带宽难以控制，加工较为复杂，不便于扩展以实现多阻带特性，实际上并不符合需求。The main drawbacks of the above various methods are insufficient integration, difficulty in controlling the frequency bandwidth, complicated processing, and inconvenient expansion to achieve multi-stopband characteristics, which actually does not meet the requirements.

发明内容Summary of the invention

以下是对本文详细描述的主题的概述。本概述并非是为了限制权利要求的保护范围。The following is an overview of the topics detailed in this document. This Summary is not intended to limit the scope of the claims.

本发明实施例提供一种滤波器，以解决如何实现结构紧凑、通带的可控性的滤波器的技术问题。Embodiments of the present invention provide a filter to solve the technical problem of how to implement a compact, passband controllability filter.

本发明实施例提供了一种滤波器，其中，包括：上层微带结构、中间介质基板和底层金属地板，其中，An embodiment of the present invention provides a filter, including: an upper layer microstrip structure, an intermediate medium substrate, and a bottom metal floor, wherein

上层微带结构包括：外环微带线、内环微带线和中心的内嵌半圆贴片，其中，The upper microstrip structure includes: an outer ring microstrip line, an inner ring microstrip line, and a center embedded semicircular patch, wherein

所述外环微带线，由两个二分之一波长谐振器通过缝隙耦合组成；The outer ring microstrip line is composed of two half-wavelength resonators through a slot coupling;

所述内环微带线，由一个环形四分之一波长谐振器和一个四分之三波长谐振器级组成，所述内环微带线嵌入所述外环微带线内；The inner ring microstrip line is composed of an annular quarter wave resonator and a three-quarter wavelength resonator stage, and the inner ring microstrip line is embedded in the outer ring microstrip line;

所述中心的内嵌半圆贴片，由两个四分之一波长谐振器组成，内嵌半圆贴片嵌入所述内环微带线内，所述内嵌半圆贴片的两个四分之一波长谐振器相互交叉排列组合成交指耦合结构；The central embedded semicircular patch consists of two quarter-wave resonators embedded in the inner ring microstrip line, and the two quarters of the embedded semicircular patch a wavelength resonator is arranged to cross each other to form a coupling structure;

所述底层金属地板上开有两个槽带，通过短路柱连接所述内环微带环和所述槽带，由所述内环微带线上的电流通过所述短路柱激励耦合起两个加载的二分之一波长的槽型谐振器。The bottom metal floor is provided with two groove strips, and the inner ring microstrip ring and the groove strip are connected by a shorting column, and the current on the inner ring microstrip line is excited and coupled through the shorting column. One loaded half-wavelength slot resonator.

可选地，上述滤波器还具有下面特点：所述内环微带线和所述外环微带线之间存在间隙。Optionally, the above filter further has the following feature: a gap exists between the inner ring microstrip line and the outer ring microstrip line.

可选地，上述滤波器还具有下面特点：Optionally, the above filter also has the following features:

所述四分之一波长谐振器和所述四分之三波长谐振器从所述间隙起分别到达开路端进行缝隙耦合。The quarter-wave resonator and the three-quarter wavelength resonator respectively reach the open end from the gap to perform slot coupling.

可选地，上述滤波器还具有下面特点： Optionally, the above filter also has the following features:

所述内环微带线是通过加载得到的。The inner loop microstrip line is obtained by loading.

所述中心的内嵌半圆贴片和所述内环微带线之间存在间隙。There is a gap between the center embedded semicircular patch and the inner ring microstrip line.

所述中心的内嵌半圆贴片是通过加载得到的。The center embedded semicircular patch is obtained by loading.

可选地，上述滤波器还具有下面特点：所述短路柱可移动地连接所述内环微带环和所述槽带。Optionally, the above filter further has the following feature: the shorting post movably connects the inner ring microstrip ring and the slot strip.

综上，本发明实施例提供一种滤波器，带外抑制能力强，结构简单，体积小巧，便于与手机电路板、CPE集成，并且成本低，易于批量生产等，能够适用于多种终端***。具有较好的带外抑制，能够满足小型化、通带可控的特性。In summary, the embodiments of the present invention provide a filter with strong out-of-band rejection capability, simple structure, small size, easy integration with a mobile phone circuit board and CPE, low cost, easy mass production, and the like, and can be applied to various terminal systems. . It has better out-of-band rejection and can meet the characteristics of miniaturization and passband controllability.

在阅读并理解了附图和详细描述后，可以明白其他方面。Other aspects will be apparent upon reading and understanding the drawings and detailed description.

附图概述BRIEF abstract

图1为本发明实施例的滤波器的俯视图；1 is a top plan view of a filter according to an embodiment of the present invention;

图2为本发明实施例的滤波器的侧视图；2 is a side view of a filter according to an embodiment of the present invention;

图3为本发明实施例的滤波器的上层图；3 is a top layer diagram of a filter according to an embodiment of the present invention;

图4为本发明实施例的滤波器的下层图；4 is a lower layer diagram of a filter according to an embodiment of the present invention;

图5为本发明实施例的滤波器效果的示意图。FIG. 5 is a schematic diagram of the effect of a filter according to an embodiment of the present invention.

本发明的实施方式Embodiments of the invention

下文中将结合附图对本申请的实施例进行详细说明。需要说明的是，在不冲突的情况下，本申请中的实施例及实施例中的特征可以相互任意组合。Embodiments of the present application will be described in detail below with reference to the accompanying drawings. It should be noted that, in the case of no conflict, the features in the embodiments and the embodiments in the present application may be arbitrarily combined with each other.

本发明实施例利用两个二分之一波长谐振器、一个加载环形四分之一波长谐振器和一个四分之三波长谐振器级联、两个耦合激励的二分之一波长谐振器级联可调、两个加载的四分之一波长交指耦合谐振器来设计四通带滤波器。表层的电磁波通过短路柱到达底层激励起槽带谐振器，且短路柱的位置根据需要的频率可选择，从而形成四个通带，每个通带的两侧都可以产生一个传输零点，采用环形结构，尺寸更小，加工更容易。Embodiments of the present invention utilize two two-wavelength resonators, one loaded annular quarter-wave resonator and one three-quarter wavelength resonator cascade, two coupled-excited half-wave resonator stages A four-passband filter is designed with a tunable, two-loaded quarter-wave interdigital coupling resonator. The electromagnetic wave of the surface layer passes through the short-circuited column to reach the bottom layer of the excitation grooved resonator, and the position of the short-circuited column According to the required frequency, four pass bands can be formed, and a transmission zero can be generated on both sides of each pass band. The ring structure is adopted, and the size is smaller and the processing is easier.

本实施例的小型化四通带滤波器包括：上层微带结构、中间介质基板和底层金属地板，其中，The miniaturized four-passband filter of the embodiment includes: an upper microstrip structure, an intermediate dielectric substrate, and a bottom metal floor, wherein

上层的微带结构包括：外环微带线、内环微带线和中心的内嵌半圆贴片。其中，The upper microstrip structure includes an outer ring microstrip line, an inner ring microstrip line, and a center embedded semicircular patch. among them,

在外环微带线的2个二分之一波长谐振器通过缝隙耦合，控制第一个通带；The two one-half-wavelength resonators on the outer ring microstrip line are coupled through the gap to control the first pass band;

第二个环(即内环微带线)和第一个环(即外环微带线)之间存在间隙，第二个环是一个加载环形四分之一波长谐振器和一个四分之三波长谐振器级联，并分别到达开路端进行缝隙耦合，嵌入所述圆环结构内，通过优化其长度会产生两个传输零点，控制第3个通带；There is a gap between the second ring (ie, the inner ring microstrip line) and the first ring (ie, the outer ring microstrip line), and the second ring is a loaded annular quarter-wave resonator and a quarter. The three-wavelength resonators are cascaded and respectively reach the open end for slot coupling, embedded in the ring structure, and two transmission zero points are generated by optimizing the length thereof to control the third pass band;

中心的内嵌半圆贴片，它和第二个环之间存在间隙，是两个四分之一波长谐振器嵌入第二个圆环结构内通过加载得到的，可以产生两个传输零点和一个传输极点，所述内嵌半圆贴片的两个四分之一波长谐振器相互交叉排列组合成交指耦合结构，相当于一个π型电容器，实现级间的电磁耦合，控制第四个通带。The center of the embedded semi-circular patch, there is a gap between the second ring and the second ring resonator is embedded in the second ring structure by loading, can generate two transmission zeros and one The transmission pole, the two quarter-wave resonators of the embedded semi-circular patch are arranged in cross-correlation with each other to form a coupling-coupling structure, which is equivalent to a π-type capacitor, realizes electromagnetic coupling between the stages, and controls the fourth pass band.

上层微带结构通过第二个微带环和短路柱到达底层是金属地板，在底层金属地板上开槽，表层的电流通过短路柱激励耦合起两个加载的二分之一波长的槽型谐振器，他们之间构成耦合结构，用于实现级间信号的耦合，控制第2个通带。The upper microstrip structure passes through the second microstrip ring and the shorting post to the bottom layer is a metal floor, and the bottom metal floor is slotted, and the surface current is excited by the shorting column to couple the two loaded half wavelength groove resonances. They form a coupling structure between them to realize the coupling of the signals between the stages and control the second pass band.

可以通过调节短路柱的位置，实现需要的谐振频率。输入和输出端口分别连接在第一个环谐振器上，第一、二个环和中心内嵌半圆贴片之间的间隙耦合形成电磁耦合，通过调节每个微带线的长度，可以灵活的调整各个谐振器的谐振频率。The required resonant frequency can be achieved by adjusting the position of the shorting post. The input and output ports are respectively connected to the first ring resonator, and the gap between the first and second rings and the central embedded semicircular patch is coupled to form an electromagnetic coupling, which can be flexibly adjusted by adjusting the length of each microstrip line. Adjust the resonant frequency of each resonator.

图1为本发明实施例的滤波器的俯视图，图2为本发明实施例的滤波器的侧视图，图3为本发明实施例的滤波器的上层图，图4为本发明实施例的滤波器的下层图，图5为本发明实施例的滤波器效果的示意图。 1 is a plan view of a filter according to an embodiment of the present invention, FIG. 2 is a side view of a filter according to an embodiment of the present invention, FIG. 3 is an upper layer diagram of a filter according to an embodiment of the present invention, and FIG. 4 is a filter according to an embodiment of the present invention; The lower layer diagram of the device, FIG. 5 is a schematic diagram of the filter effect of the embodiment of the present invention.

如图2所示，本实施例的滤波器包括：上层微带结构、中间介质基板6和底层金属地板5。As shown in FIG. 2, the filter of this embodiment includes an upper microstrip structure, an intermediate dielectric substrate 6, and an underlying metal floor 5.

上层的微带结构包括：输入端口11、输出端口22、两个二分之一波长谐振器、一个加载环形四分之一波长谐振器和一个四分之三波长谐振器级联。其中，在外环微带线的一个二分之一波长谐振器由微带线311、312、313、315、316、317、32组成，左右两边中心对称形成两个二分之一波长谐振器；第二个环是通过第一个环加载得到的，它是一个加载环形四分之一波长谐振器和一个四分之三波长谐振器级联，环形四分之一波长谐振器由微带线321组成，环形四分之三波长谐振器由微带322、323组成；中心半圆贴片331、332内嵌在第二个环上加载得到的，它和第二个环之间存在间隙，是两个四分之一波长谐振器。下层贴片是金属地板5，表层的电流通过第二个环和短路柱34到达下层，在金属地板5上开槽通过上层短路柱激励形成两个对称加载的二分之一波长耦合谐振器，他们分别为槽带41、42。The upper microstrip structure includes an input port 11, an output port 22, two half-wavelength resonators, a loaded annular quarter-wave resonator, and a three-quarter-wavelength resonator cascade. Wherein, a half-wavelength resonator in the outer ring microstrip line is composed of

microstrip lines

311, 312, 313, 315, 316, 317, 32, and the left and right sides are symmetric with respect to each other to form two half-wavelength resonators. The second loop is obtained by the first loop loading, which is a loaded circular quarter-wave resonator and a three-quarter-wavelength resonator cascade, and the annular quarter-wave resonator is microstriped. The line 321 is composed of a ring-shaped three-quarter wavelength resonator composed of

microstrips

322 and 323; the central

semi-circular patches

331, 332 are embedded in the second ring, and there is a gap between the ring and the second ring. It is two quarter-wave resonators. The lower patch is a metal floor 5, the current of the surface layer reaches the lower layer through the second ring and the shorting column 34, and the metal floor 5 is slotted by the upper short-circuiting column to form two symmetrically loaded one-half wavelength coupling resonators. They are slotted

belts

41 and 42, respectively.

其中，微带线313是一个开路枝节，经过1/4波长通过微带线312、311阻抗变换后到达输入端口11处相当于短路，从而在第一通带右边产生一个传输零点；微带线317是一个开路枝节，经过1/4波长通过微带线316、315阻抗变换后到达输入端口11处相当于短路，从而在第一通带左边产生一个传输零点。微带线321是一个开路枝节，经过1/4波长通过微带线32到达输入端口11处相当于短路，从而在第3个通带右侧产生一个传输零点；微带线322是一个开路枝节，经过3/4波长通过微带线323的到达微带32处相当于短路，从而在第3个通带左侧产生一个传输零点。Wherein, the microstrip line 313 is an open branch, which is equivalent to a short circuit after reaching the input port 11 through the impedance transformation of the

microstrip lines

312 and 311 after 1/4 wavelength, thereby generating a transmission zero point on the right side of the first pass band; the microstrip line 317 is an open branch, which is equivalent to a short circuit after reaching the input port 11 through the impedance transformation of the

microstrip lines

316 and 315 through the 1/4 wavelength, thereby generating a transmission zero point on the left side of the first pass band. The microstrip line 321 is an open stub, which is equivalent to a short circuit through the microstrip line 32 to the input port 11 through 1/4 wavelength, thereby generating a transmission zero point on the right side of the third pass band; the microstrip line 322 is an open branch The passage of the 3/4 wavelength through the microstrip line 323 to the microstrip 32 is equivalent to a short circuit, thereby generating a transmission zero point on the left side of the third pass band.

底层开槽41的电磁场是表层第二个环通过短路柱34激励起的，通过第三个通带激励起第二个通带，从开槽41通过短路柱34再分别经过微带线321和322、323后到达微带32，在端口11处，分别经过了3/4和5/4个波长的微带线，从开路变为短路，从而在第2个通带右侧和左侧分别产生一个传输零点。当短路柱34移动到不同的位置，得到的谐振频率也会不同，当短路柱34移动到微带312处时，加载到微带313处的电磁波通过微带312后往微带311处传输，同时也会通过短路柱34传到底层的开槽41，当开槽41的长度大于微带311时，那么开槽41形成的第一个通带的传输零点，而表层的第一个环将形成第二个通带的传输零点。The electromagnetic field of the bottom layer slot 41 is that the second ring of the surface layer is excited by the shorting column 34, and the second pass band is excited by the third pass band, and the microstrip line 321 is passed from the slot 41 through the shorting column 34 and After 322 and 323, the microstrip 32 is reached. At the port 11, the microstrip lines of 3/4 and 5/4 wavelengths respectively pass through the open circuit to the short circuit, so that the right side and the left side of the second pass band respectively Generate a transmission zero. When the shorting post 34 moves to a different position, the resulting resonant frequency will also be different. When the shorting post 34 moves to the microstrip 312, the electromagnetic wave loaded to the microstrip 313 passes through the microstrip 312 and is transmitted to the microstrip 311. At the same time, it is also transmitted to the underlying slot 41 through the shorting post 34. When the length of the slot 41 is larger than the microstrip 311, then the first passband formed by the slot 41 has a zero transmission point, and the first layer of the surface layer The loops will form the transmission zero of the second passband.

从交指耦合的末端开路经过1/4波长通过微带331、33、32阻抗变换后，在馈电端口位置相当于短路，其等效总长度是第四个通带上侧零点频率所对应的1/4波长，从而在第四个通带的右侧产生一个传输零点。通过调节每个环带的长度可以优化四个通带的传输零点位置，得到需要的四通带滤波器。After the end of the interdigital coupling is opened by the 1/4 wavelength through the

microstrips

331, 33, 32 impedance transformation, the position of the feeding port is equivalent to a short circuit, and the equivalent total length is corresponding to the frequency of the upper zero point of the fourth passband. The 1/4 wavelength, resulting in a transmission zero on the right side of the fourth passband. By adjusting the length of each annulus, the transmission zero position of the four passbands can be optimized to obtain the required four-passband filter.

第一通带的谐振频率是由外环长度决定的，如果在微带313和微带317加载奇模激励，那么中心位置处的电压值为零，即在加载微带32处的电压值为零，相当于该处接地，所以加载的第二个环对奇模的谐振频率不会产生影响。如果在微带313和微带317加载偶模激励，那么在加载微带32处就有电流流过，并且到达第二个微带环，再由第二个环带分别通过微带321，微带323、322再通过短路柱34到达底层，从而激励起槽带41、42的感应电流。另一方面，电流从微带32流过后经过微带33到达中心半圆贴片331、332。短路柱34的位置可以移动，当到达微带32处时，第一个环加载的耦合激励，电流也流过短路柱34到达底层的槽带，从而激励起感应电流，此时的通带频率就会发生变化，由槽带的长度决定。这样偶模激励时谐振频率将由第一个环的长度、微带32、第二个环的长度、底层槽带长度、微带33长度、中心半圆贴片半径共同决定。从而，可以通过奇偶模定理调节第一个微带环、第二个微带环、内嵌半圆贴片、槽带的长度，从而得到第一、第二、第三、第四个通带的谐振频率。The resonant frequency of the first passband is determined by the length of the outer loop. If the odd-mode excitation is applied to the microstrip 313 and the microstrip 317, the voltage at the center is zero, ie, the voltage at the microstrip 32 is loaded. Zero is equivalent to grounding at this point, so the second ring loaded does not affect the resonant frequency of the odd mode. If the even mode excitation is applied to the microstrip 313 and the microstrip 317, then current flows through the loaded microstrip 32 and reaches the second microstrip ring, which in turn passes through the microstrip 321 respectively. The

strips

323, 322 then pass through the shorting post 34 to the bottom layer, thereby energizing the induced currents of the strip strips 41, 42. On the other hand, current flows from the microstrip 32 through the microstrip 33 to the central

semicircular patches

331, 332. The position of the shorting post 34 can be moved. When the microstrip 32 is reached, the coupling of the first ring loading is excited, and the current also flows through the shorting post 34 to reach the bottom slot, thereby exciting the induced current, and the passband frequency at this time. It will change, depending on the length of the slot. The resonant frequency of the even mode excitation will be determined by the length of the first ring, the length of the microstrip 32, the length of the second ring, the length of the underlying slot, the length of the microstrip 33, and the radius of the center semicircle patch. Therefore, the lengths of the first microstrip ring, the second microstrip ring, the embedded semicircular patch, and the groove band can be adjusted by the odd and even modulus theorem, thereby obtaining the first, second, third, and fourth passbands. Resonant frequency.

每个通带的带宽需要调节微带之间的耦合系数得到。微带312、314(微带316、318)之间的间距是调节第一通带的带宽的，它们之间的间距越小，耦合系数越大，那么第一通带的带宽越宽；微带321和322之间的间距是调节第三通带的带宽的，槽带41和42之间的间距是调节第二通带的带宽的，半圆贴片331和332之间是交指耦合，类似于一个π型电容器，其交指间距和宽度是调节第四通带带宽的。当间距越小时，耦合系数越大，通带的带宽就越宽，从而实现四通带滤波器。The bandwidth of each passband needs to be adjusted by adjusting the coupling coefficient between the microstrips. The spacing between the microstrips 312, 314 (microstrips 316, 318) is to adjust the bandwidth of the first passband, the smaller the spacing between them, the larger the coupling coefficient, then the wider the bandwidth of the first passband; The spacing between the

strips

321 and 322 is to adjust the bandwidth of the third pass strip. The spacing between the

strips

41 and 42 is to adjust the bandwidth of the second pass strip. The

semicircular patches

331 and 332 are interdigitated. Similar to a π-type capacitor, its pitch and width are adjusted to the fourth passband bandwidth. When the pitch is smaller, the larger the coupling coefficient, the wider the bandwidth of the pass band, thereby realizing a four-pass band filter.

本实施例的小型化四通带滤波器可以很好的和PCB集成，直接应用到终端的PCB板上，可以根据布局的需要进行调整；本实施例的小型化四通带滤波器每个环的长度、宽度都可以调整，从而实现不同的谐振频率；本实施例的小型化四通带滤波器每个环的间距都是可以调节的，从而产生不同的耦合效果；The miniaturized four-passband filter of the embodiment can be well integrated with the PCB and directly applied to the PCB of the terminal, and can be adjusted according to the layout requirements; the miniaturized four-passband filter of this embodiment is used for each ring. The length and width can be adjusted to achieve different resonant frequencies; this embodiment The miniaturized four-pass band filter can adjust the spacing of each ring to produce different coupling effects;

本实施例的滤波器第三个微带环(指中心的内嵌半圆贴片)的交指宽度、缝隙是可以调节的；The intersection width and the gap of the third microstrip ring (referring to the center embedded semicircular patch) of the filter of this embodiment are adjustable;

本实施例的滤波器第二个微带环和中心内嵌半圆贴片可以都是加载得到的；The second microstrip ring and the central inline semicircular patch of the filter of this embodiment may be loaded;

本实施例的滤波器的底层槽型谐振器是通过上层的电磁波激励耦合得到的两个二分之一波长谐振器；The bottom trench type resonator of the filter of this embodiment is two half-wavelength resonators obtained by excitation coupling of upper layer electromagnetic waves;

本实施例的短路柱的位置可以任意调节，形成不同的频率的第二通带。The position of the shorting post of this embodiment can be arbitrarily adjusted to form a second pass band of different frequencies.

本实施例的滤波器的电路结构紧凑、体积小巧，平面结构易于和其他微带电路集成；滤波器的地面是完整的地，可以有效地防止信号泄漏；通过适当调节环的长度、宽度，及其间距，可以进一步调整谐振频率的位置、阻抗带宽及其带外抑制能力，可以提高滤波器的通带频率选择性。The filter of the embodiment has a compact circuit structure and a compact size, and the planar structure is easy to integrate with other microstrip circuits; the ground of the filter is a complete ground, which can effectively prevent signal leakage; by appropriately adjusting the length and width of the ring, and The pitch can further adjust the position of the resonant frequency, the impedance bandwidth and its out-of-band rejection capability, and can improve the passband frequency selectivity of the filter.

以上所述仅为本申请应用于无线接入产品的一个实施例而已，凡在本方法的精神和原则之内，环形微带的长度、宽度，环间的间距，以及耦合槽带的形状方面所作的任何修改、等同替换、改进等，均应包含在本申请的保护范围之内。The above description is only one embodiment of the present application applied to the wireless access product. The length, the width of the annular microstrip, the spacing between the rings, and the shape of the coupling groove are all within the spirit and principle of the method. Any modifications, equivalent substitutions, improvements, etc., are intended to be included within the scope of this application.

工业实用性Industrial applicability

上述方案记载的滤波器带外抑制能力强，结构简单，体积小巧，便于与手机电路板、CPE集成，并且成本低，易于批量生产等，能够适用于多种终端***。 The filter described in the above scheme has strong outer band rejection capability, simple structure, small size, convenient integration with mobile phone circuit boards and CPEs, low cost, easy mass production, and the like, and can be applied to various terminal systems.

Claims

一种滤波器，包括：上层微带结构、中间介质基板和底层金属地板，其中，A filter comprising: an upper microstrip structure, an intermediate dielectric substrate, and an underlying metal floor, wherein

上层微带结构包括：外环微带线、内环微带线和中心的内嵌半圆贴片，其中，The upper microstrip structure includes: an outer ring microstrip line, an inner ring microstrip line, and a center embedded semicircular patch, wherein

所述外环微带线，由两个二分之一波长谐振器通过缝隙耦合组成；The outer ring microstrip line is composed of two half-wavelength resonators through a slot coupling;

所述内环微带线，由一个环形四分之一波长谐振器和一个四分之三波长谐振器级组成，所述内环微带线嵌入所述外环微带线内；The inner ring microstrip line is composed of an annular quarter wave resonator and a three-quarter wavelength resonator stage, and the inner ring microstrip line is embedded in the outer ring microstrip line;

所述中心的内嵌半圆贴片，由两个四分之一波长谐振器组成，内嵌半圆贴片嵌入所述内环微带线内，所述内嵌半圆贴片的两个四分之一波长谐振器相互交叉排列组合成交指耦合结构；The central embedded semicircular patch consists of two quarter-wave resonators embedded in the inner ring microstrip line, and the two quarters of the embedded semicircular patch a wavelength resonator is arranged to cross each other to form a coupling structure;

所述底层金属地板上开有两个槽带，通过短路柱连接所述内环微带环和所述槽带，由所述内环微带线上的电流通过所述短路柱激励耦合起两个加载的二分之一波长的槽型谐振器。The bottom metal floor is provided with two groove strips, and the inner ring microstrip ring and the groove strip are connected by a shorting column, and the current on the inner ring microstrip line is excited and coupled through the shorting column. One loaded half-wavelength slot resonator.
如权利要求1所述的滤波器，其中：The filter of claim 1 wherein:

所述内环微带线和所述外环微带线之间存在间隙。There is a gap between the inner loop microstrip line and the outer loop microstrip line.
如权利要求2所述的滤波器，其中：The filter of claim 2 wherein:

所述四分之一波长谐振器和所述四分之三波长谐振器从所述间隙起分别到达开路端进行缝隙耦合。The quarter-wave resonator and the three-quarter wavelength resonator respectively reach the open end from the gap to perform slot coupling.
如权利要求1所述的滤波器，其中：The filter of claim 1 wherein:

所述内环微带线通过加载得到。The inner loop microstrip line is obtained by loading.
如权利要求1所述的滤波器，其中：The filter of claim 1 wherein:

所述中心的内嵌半圆贴片和所述内环微带线之间存在间隙。There is a gap between the center embedded semicircular patch and the inner ring microstrip line.
如权利要求1所述的滤波器，其中：The filter of claim 1 wherein:

所述中心的内嵌半圆贴片通过加载得到。The center embedded semicircular patch is obtained by loading.
如权利要求1－6任一项所述的滤波器，其中：A filter according to any of claims 1-6, wherein:

所述短路柱可移动地连接所述内环微带环和所述槽带。 The shorting post movably connects the inner ring microstrip ring and the slot strip.