匹配负载是一种重要的单端口无源器件，常用于微波电路中，主要功能是对输入的电磁能量进行吸收，提升电路的匹配性能。目前常见的匹配负载形式有矩形波导、圆波导和同轴线等，在微波测量系统、通信系统和雷达等系统中被广泛使用。随着无线电子系统的发展，传统的矩形波导、圆波导和同轴线等三维结构形式的匹配负载体积大、成本高、加工困难、不易集成等，越来越难适应系统高集成度的发展需求，低剖面、平面化的器件与电路是一种发展趋势。因此，研究和发展低成本、小型化、低剖面、平面化的匹配负载的对于现代微波电路与系统的发展具有十分重要的意义。The matching load is an important single-port passive device, which is often used in microwave circuits. Its main function is to absorb the input electromagnetic energy and improve the matching performance of the circuit. At present, the common matching load forms include rectangular waveguide, circular waveguide and coaxial line, etc., which are widely used in microwave measurement systems, communication systems and radar systems. With the development of radio subsystems, traditional three-dimensional structures such as rectangular waveguides, circular waveguides, and coaxial lines have large matching loads, high costs, difficult processing, and difficulty in integration, making it more and more difficult to adapt to the development of high system integration. Demand, low profile, planar devices and circuits are a development trend. Therefore, the research and development of low-cost, miniaturized, low-profile, and planar matched loads are of great significance to the development of modern microwave circuits and systems.

微带线是一种典型的平面传输线，被广泛应用，它易于加工，且具有高集成度的特性，因此，基于微带线形式的低成本、小型化、低剖面、平面化的匹配负载具有重要的应用前景。Microstrip line is a typical planar transmission line, which is widely used. It is easy to process and has the characteristics of high integration. Therefore, the low-cost, miniaturized, low-profile, and planarized matching load based on the microstrip line has important application prospects.

发明内容SUMMARY OF THE INVENTION

本发明的目的是提供一种小型化平面匹配负载，基于有耗滤波器级联，实现微带形式的平面化匹配负载，同时具有成本低、尺寸小、剖面低、易集成、且易于加工和装配的优点，适用于微波测量、无线通信和雷达等系统。The purpose of the present invention is to provide a miniaturized planar matching load, which is based on lossy filter cascade, realizes the planar matching load in the form of microstrip, and has the advantages of low cost, small size, low profile, easy integration, and easy processing and The advantages of assembly are suitable for systems such as microwave measurement, wireless communication and radar.

为了实现上述目的，本发明提出了一种基于有耗交指带通滤波器级联实现滤波特性的小型化平面匹配负载。其具体技术方案如下：In order to achieve the above purpose, the present invention proposes a miniaturized planar matching load based on cascading lossy interdigitated bandpass filters to realize filtering characteristics. Its specific technical solutions are as follows:

一种小型化平面匹配负载，由多个有耗交指带通滤波器级联实现，包括金属微带层、介质基板和金属接地板；信号输入端为阻抗50欧姆微带线，终端短路或开路，形成一个单端口的平面匹配负载；所述的介质基板为有耗介质基板，金属化通孔将金属微带层和金属接底板相连接，所述的金属微带层在有耗介质基板上表面，金属接地板在有耗介质基板下表面；所述的有耗交指带通滤波器由多个一端开路一端短路的四分之一波长微带谐振器组成，微带谐振器之间采用平行耦合方式，有耗交指带通滤波器的输入/输出端采用抽头方式与微带谐振器实现磁耦合；有耗交指带通滤波器之间通过一段微带线进行级联。A miniaturized plane matching load, which is realized by cascading multiple lossy interdigital bandpass filters, including metal microstrip layer, dielectric substrate and metal grounding plate; open circuit to form a single-port plane matching load; the dielectric substrate is a lossy dielectric substrate, and the metallized through holes connect the metal microstrip layer and the metal connection base plate, and the metal microstrip layer is on the lossy dielectric substrate On the upper surface, the metal ground plate is on the lower surface of the lossy dielectric substrate; the lossy interdigital bandpass filter is composed of a plurality of quarter-wavelength microstrip resonators with one end open and the other short, and the microstrip resonators are Using the parallel coupling method, the input/output end of the lossy interdigital bandpass filter is magnetically coupled with the microstrip resonator by means of taps; the lossy interdigital bandpass filters are cascaded through a microstrip line.

本发明提出的一种小型化平面匹配负载的工作原理如下：The working principle of a miniaturized plane matching load proposed by the present invention is as follows:

微波信号从所述的小型化平面匹配负载的信号输入端口馈入，进入级联的有耗交指带通滤波器，微波信号的电磁能量在通过有耗交指带通滤波器的过程中，一部分被有耗介质基板吸收转化为热能，剩余的微波信号电磁能量继续传输到下一级有耗交指带通滤波器；最终剩余微波信号电磁能量在到达终端时被反射，反射的电磁能量反向传输到各个有耗交指带通滤波器，并被各个有耗交指带通滤波器分别吸收能量转化为热能，反向传输到输入端时最终剩余微波信号电磁能量已经很小，可以忽略，从而实现了输入端口的良好的阻抗匹配。The microwave signal is fed from the signal input port of the miniaturized planar matching load and enters the cascaded lossy interdigital bandpass filter. During the process of passing through the lossy interdigital bandpass filter, the electromagnetic energy of the microwave signal, Part of it is absorbed by the lossy dielectric substrate and converted into heat energy, and the remaining microwave signal electromagnetic energy continues to be transmitted to the next-level lossy interdigital bandpass filter; finally, the remaining microwave signal electromagnetic energy is reflected when it reaches the terminal, and the reflected electromagnetic energy is reversed. It is transmitted to each lossy interdigital bandpass filter, and the energy is absorbed by each lossy interdigital bandpass filter and converted into heat energy. When the reverse transmission is transmitted to the input end, the final residual microwave signal electromagnetic energy is very small and can be ignored. , so as to achieve a good impedance matching of the input port.

本发明提出的一种小型化平面匹配负载，易于与其它电路进行集成；它基于分布式传输线设计，模型精准，可应用于毫米波/太赫兹电路与系统中；它具有成本低、尺寸小、剖面低、易集成、易加工和装配简单等优点，在微波测量、无线通信和雷达等系统中具有广泛的应用前景。The miniaturized plane matching load proposed by the present invention is easy to integrate with other circuits; it is based on distributed transmission line design, the model is accurate, and can be applied to millimeter wave/terahertz circuits and systems; it has the advantages of low cost, small size, With the advantages of low profile, easy integration, easy processing and simple assembly, it has wide application prospects in microwave measurement, wireless communication and radar systems.

附图说明Description of drawings

图1是本发明提出的小型化平面匹配负载结构的正面视图；Fig. 1 is the front view of the miniaturized plane matching load structure proposed by the present invention;

图2是具体实施例的小型化平面匹配负载的S参数仿真曲线；Fig. 2 is the S-parameter simulation curve of the miniaturized plane matching load of the specific embodiment;

附图中标识对应名称为：The corresponding names in the attached drawings are:

(1)金属微带层，(2)介质基板，(3)信号输入端，(4)多阶交指滤波器，(5)金属化通孔。(1) metal microstrip layer, (2) dielectric substrate, (3) signal input end, (4) multi-order interdigital filter, (5) metallized through hole.

具体实施方式Detailed ways

下面结合附图和具体实施例对本发明做进一步的说明。The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

本实施例的小型化平面匹配负载结构如附图1所示，其终端开路，使用损耗角正切为0.02、介电常数为4.4、厚度为0.4mm的FR-4介质基板实现该电路。将6个有耗交指滤波器级联，其中，有耗交指滤波器为7阶宽带带通滤波器，中心频率为8.5GHz。微波信号从50Ω的输入端口进入级联的有耗交指滤波器，在终端被反射后，反向传输到达输入端口时微波信号能量几乎已被小型化平面匹配负载完全吸收。The miniaturized planar matching load structure of this embodiment is shown in FIG. 1 , the terminal is open, and the circuit is realized by using a FR-4 dielectric substrate with a loss tangent of 0.02, a dielectric constant of 4.4, and a thickness of 0.4 mm. Six lossy interdigital filters are cascaded, wherein the lossy interdigital filter is a 7th-order broadband bandpass filter with a center frequency of 8.5GHz. The microwave signal enters the cascaded lossy interdigital filter from the input port of 50Ω. After the terminal is reflected, the microwave signal energy is almost completely absorbed by the miniaturized planar matching load when it reaches the input port in reverse transmission.

图2是本实施例的小型化平面匹配负载的输入端口的S参数仿真曲线。由图可以看出，在7.7GHz-10.5GHz频率范围(相对带宽33％)内，该小型化平面匹配负载输入回波损耗大约在20dB左右，小型化平面匹配负载总的电长度为2个波长左右。FIG. 2 is an S-parameter simulation curve of the input port of the miniaturized planar matching load of the present embodiment. It can be seen from the figure that in the frequency range of 7.7GHz-10.5GHz (relative bandwidth 33%), the input return loss of the miniaturized planar matching load is about 20dB, and the total electrical length of the miniaturized planar matching load is 2 wavelengths. about.

Claims

1. A miniaturized planar matched load, characterized in that: the miniaturized planar matching load is based on a distributed transmission line design, and the model is accurate; the metal micro-strip layer is arranged on the upper surface of the lossy dielectric substrate, and the metal grounding plate is arranged on the lower surface of the lossy dielectric substrate.

2. The miniaturized planar matched load of claim 1, which is implemented by cascading a plurality of lossy interdigital band-pass filters through microstrip lines, wherein each lossy interdigital band-pass filter consists of a plurality of quarter-wavelength microstrip resonators with one open end and one short circuit, and the microstrip resonators are coupled in parallel.

3. The miniaturized planar matched load of claim 1 or 2, wherein: in the process that the electromagnetic energy of the microwave signal passes through the lossy interdigital band-pass filter, a part of the electromagnetic energy is absorbed by the lossy dielectric substrate and converted into heat energy, and then the electromagnetic energy of the microwave signal is continuously transmitted to the next stage of lossy interdigital band-pass filter.

4. The miniaturized planar matched load of claims 1, 2 and 3, wherein: finally, the electromagnetic energy of the residual microwave signals is reflected when reaching the terminal, the reflected electromagnetic energy is reversely transmitted to each lossy interdigital band-pass filter, the energy is respectively absorbed by each lossy interdigital band-pass filter and converted into heat energy, the electromagnetic energy is very small and can be ignored when the microwave signals are reversely transmitted to the input end, and therefore good impedance matching of the input port is achieved.