基于SIW技术的毫米波滤波器研究与设计

基于基片集成波导（substrate integrated waveguide,SIW）结构设计了两款四阶的耦合带通滤波器,使用三维全波电磁场仿真软件HFSS对设计的两款滤波器进行了仿真设计和优化.由仿真结果分析得出,两款滤波器的工作频率均位于毫米波频段.第一款SIW滤波器实现了切比雪夫型响应,中心频率为20 GHz,带宽为2 GHz,通带内的插入损耗低于1.5 dB,回波损耗低于-20 dB,在阻带中对信号的衰减程度可以达到50 dB.第二款SIW滤波器实现了准椭圆函数型的响应,中心频率为29.1 GHz,带宽为300 MHz,通带内的插入损耗低于1 dB,回波损耗低于-20 dB,在通带到阻带的过渡中实现了两个陷波点.仿真结果表明,在毫米波滤波器设计中引入SIW结构,有利于优化滤波器尺寸,得到较好的滤波器性能指标,是毫米波滤波器发展的一个重要方向.     

Design and performance of coplanar waveguide slotline bandpass filter

This paper describes the work involved in designing a coplanar waveguide -slotline bandpass filter. The filter designed to achieve at least -30dB insertion loss (S₂₁)in the stopband (8 to 8.5; 9.3 to 10 GHz) and less than -0.2 dB in the passband (8.75 to 9.05 GHz), with a centre frequency of 8.9 GHz. The filter and transition were fabricated on 1.27 mm thick RT-Duriod 6010.2 substrate and S-parameters were tested using standard SMA connectors with an HP-8510A network analyser.     

Broadband substrate integrated waveguide to rectangular waveguide transition with fin-line

A novel broadband transition from a substrate integrated waveguide to a rectangle waveguide with an antipodal fin-line in its quasi-TE mode is presented. Impedance match and field mode gradual changing of transition circuits have been carefully analysed and performed. Experimental results show about a 1.6 dB insertion loss and greater than 12 dB return loss for back-to-back transitions over 10 GHz bandwidth from 26.5 to 40 GHz, so single transition insertion loss is about 0.8 dB. The transition is proposed for low-loss front-end circuits in the millimetre-wave band.     

Electronically switchable and tunable coplanar waveguide-slotlineband-pass filters

A coplanar waveguide (CPW)-slotline bandpass filter is described. The circuit allows planar integration of active and passive semiconductor devices both in series and in shunt. A microstrip-to-slotline transition designed to test the filter is also described. Two of the transitions exhibit an insertion loss of less than 1.0 dB over the 2.0-4.0-GHz range. A three-section CPW-slotline bandpass filter demonstrates an insertion loss of less than 0.2 dB over the passband centered at 2.9 GHz. A three-section CPW-slotline switchable bandpass filter integrated with three p-i-n diodes is discussed. It has a 0.7-dB insertion loss in the passband when the p-i-n diodes are off and a 25.0-dB isolation across the entire band when the p-i-n diodes are on. A three-section CPW-slotline varactor-tunable filter integrated with three varactor diodes is presented, showing a 2.0-dB insertion loss and over 20% electronic tuning range. Simple transmission line circuit models are used to optimize the design     

A Fully Embedded 60-GHz Novel BPF for LTCC System-in-Package Applications

In this paper, a novel LTCC stripline (SL) 60-GHz band-pass filter (BPF) composed of transitions to coplanar waveguide (CPW) pads for monolithic microwave integrated circuit integration is presented. For low-loss interconnection with active devices, a CPW-to-SL vertical via transition integrating air cavities and a CPW-to-CPW planar transition using internal ground planes are proposed and implemented. The fabricated transition shows an insertion loss of 1.6 dB and a reflection loss below -20 dB at the passband of the filter. The implemented SL BPF using dual-mode patch resonators shows a center frequency of 60.4 GHz, 3.5 % bandwidth, and reflection losses below -15 dB at the passband. Excluding the insertion loss of the transitions, the filter insertion loss reveals 4.0 dB     

波导带通滤波器与微带转换装置的设计

利用三维仿真软件HFSS首先设计了K波段7阶电感E面带通波导滤波器,以及波导-微带转换器.其中波导滤波器的中心频率为19 GHz,带宽为3 GHz,带内损耗小于0.1 dB,端口反射小于-20 dB;而波导-微带的转换器在16～20.8 GHz的带宽内端口反射小于-20 dB,带内损耗小于0.1 dB.然后将两者有效结合为一体,其工作带宽为17.5～20.5 GHz,带内损耗为0.3 dB,端口反射小于-15 dB,带外抑制小于-30 dB,可以满足实际系统应用的需求.     

Broadband transition between half mode substrate integrated waveguide and rectangular waveguide

A broadband transition between a half mode substrate integrated waveguide and a rectangular waveguide with an antipodal fin-line in its quasi-TEM mode is presented. Experimental results show about 1.3 dB insertion loss and below 215 dB return loss for a back-toback double transition over 10 GHz bandwidth from 26.5 to 40 GHz (the single transition insertion loss is about 0.65 dB). The transition may be used in low-loss and low-noise front-end circuits of the microwave and millimetre-wave bands.     

Broadband transition between air-filled waveguide and substrate integrated waveguide

A Ka-band broadband transition between an air-filled waveguide and a substrate integrated waveguide (SIW) is proposed. The transition is realised by using a radial probe inserted into the height-tapered metal waveguide. Results show that an insertion loss less than 2.5 dB and a return loss better than 14 dB in the frequency band 28.3-39.5 GHz are obtained for a back-to-back structure     

Half Mode Substrate Integrated Waveguide (HMSIW) Directional Filter

A double-loop directional filter is described and realized in this work by using a novel guided-wave structure called half mode substrate integrated waveguide (HMSIW), which retains the attractive performances of substrate integrated waveguide (SIW) with a nearly half reduction in size compared to the original SIW version. The demonstrated filter is designed at 12 GHz with less than 3.2 dB insertion loss for a 250-MHz bandwidth, and the minimum insertion loss is 1.5 dB. It presents low insertion loss, high power capacity in planar compact configuration with a standard PCB fabrication process.     

一种紧缩结构的新型毫米波基片集成波导滤波器

提出了一种紧缩结构的新型毫米波基片集成波导(SIW)滤波器,在结构紧缩的同时性能得到了显著改善.在设计的一组SIW毫米波滤波器中,长度从传统滤波器的23.1mm压缩到新型滤波器的12mm.测试结果显示新型滤波器阻带衰减大于54dB,相对于性能相近的传统SIW滤波器改善12dB以上.具有超过50dB衰减的阻带宽度超过9GHz.上边带过渡特性更陡,同时仍保持了传统SIW滤波器所具有的陡峭下边带特性和低损耗特性.     

All-planar dual-mode asymmetric filters at Ka-band

All-planar dual-mode inductive asymmetric filters utilizing new planar microstrip to dielectric-loaded rectangular waveguide transitions at Ka-band were presented and built in this work. The conventional, three-dimensional metallic rectangular waveguide dual-mode filters can be implemented into mature PCB technology with a much easier and lower-cost fabrication process on the basis of the all-planar feature of the transition. This work demonstrates two Ka-band filter examples with center frequency at 31 GHz and bandwidth at 1 GHz and 2 GHz. The measured minimum insertion loss of each case was, respectively, 2.68 and 1.12 dB, with greater than 10 dB return loss in the passband. Moreover, the measured side-band attenuation (near passband) is larger than 30 dB due to the transmission zeros at each side of the passband.     

A vertically integrated micromachined filter

A 10-GHz filter constructed of slot-coupled micromachined cavities in silicon is presented. The novel character of the filter lies in its structure, which consists of a microstrip feed to cavities via slot apertures and three vertically stacked slot-coupled cavities. The cavities are essentially reduced-height waveguide resonators. The measured results are presented and compared to a finite-element-method model. The simulated model has a bandwidth of 4% with an insertion loss of 0.9 dB at 10.02 GHz. The measured filter yields a 3.7% bandwidth with a deembedded insertion loss of 2.0 dB at 10.01 GHz. Various loss mechanisms are examined to explain the difference between simulated and measured insertion loss     

Mode conversion at GCPW-to-microstrip-line transitions

Mode conversion at the transition between grounded coplanar waveguide (GCPW) and microstrip line is demonstrated. Experimental results show the effect of overmoding in a conductor-backed coplanar waveguide on the transition behavior. A simple micromachining solution is used to cancel the parasitic modes triggered by the transition in the GCPW feed line. This results in an insertion loss of 0.3 dB and a return loss better than -18 dB from 75 to 110 GHz. The transition can prove very useful for millimeter-wave packaging and interconnects     

0.22 THz Waveguide Bandpass Filter with High Stop-Band Suppression

A terahertz (THz) waveguide band-pass filter using an iris inductive window coupled structure was designed and fabricated. The filter was designed at 0.22 THz with a pass band of 20 GHz. The measured results show that the center frequency is 0.218 THz with a pass band of 0.205 THz to 0.231 THz, the minimum insertion loss is 1.26 dB at 0.224 THz, and the return loss is less than 13.1 dB. The stop-band suppression is 65.6 dB at 0.193 THz and 51.8 dB at 0.243 THz, respectively, which means a good performance of high stop-band suppression. A good agreement exists between the measured S-parameters and the simulated ones, especially in the upper band. The proposed THz waveguide filter has potential applications in THz communications.     

A silicon micromachined four-pole linear phase filter

A 27-GHz four-pole linear phase filter constructed of micromachined cavities in silicon is presented. The structure of the filter consists of four side-by-side horizontally oriented cavities, which are coupled in turn by evanescent waveguide sections with three direct-couplings and one cross-coupling between the first and fourth cavity resonators. The cavities are reduced-height waveguide resonators and are fed by microstrip lines through slot apertures. A time-domain tuning technique is employed to improve the efficiency of the design synthesis. The measured results are presented and compared to those predicted by a finite-element-method model. The simulated filter response has a bandwidth of 2.2% centered at 27.480 GHz with an insertion loss of 1.4 dB at that frequency. The measured performance indicates a 1.9% bandwidth centered at 27.604 GHz with a deembedded insertion loss of 1.6 dB at that frequency and a measured unloaded Q of 1465.     

A Novel GCPW to Rectangular Waveguide Transition for 60 GHz Applications

A new type of grounded coplanar waveguide (GCPW) to rectangular waveguide transition in an LTCC multi-layer structure for 60 GHz applications is proposed in this letter. The GCPW and rectangular waveguide are fully integrated on the same substrate, and the ground wall of the rectangular waveguide is made up of a staggered via fence. The transition is accomplished by inserting a bent short stub. We analyze and prove the novel transition structure by applying an equivalent circuit model. Measured results for a single transition show that the insertion loss is 0.345 dB at 59 GHz and the bandwidth is 6.3 GHz. The proposed transition structure with very low loss at a large bandwidth is very suitable for a SiP of 60 GHz WPAN applications.      

一种新型毫米波矩形波导-微带过渡结构

介绍了一种新颖的、适用于毫米波频段的矩形波导-微带过渡电路结构。该过渡电路具有插入损耗低、频带宽、重复性好的特性。其矩形波导E面相对于微带电路面,以及电磁信号传输方向的位置与脊波导-微带过渡相同。该过渡电路的微带线与波导的转换部分采用非接触式结构,并设计了可调节元件,从而在有一定加工误差的条件下改善其产品传输特性。利用高频仿真软件CST,在Ka频段进行了优化仿真,并对利用其优化值所设计的一对背靠背的电路实物进行了测试,在32～40 GHz的频率范围内,插入损耗小于2.36 dB,回波损耗大于7.22 dB;在整个Ka频段内,插入损耗小于3.49 dB。     

SIR结构ACPW滤波器研究

文章提出将SIR谐振器结构应用于非对称共面波导传输线中,设计了一种新型SIR结构非对称共面波导带阻滤波器。通过四个SIR谐振单元在非对称共面波导传输线中级联,有效地改善了滤波器的插损和带宽。结果显示,本滤波器中心频率为1．8GHz,最小插损为0．4dB,相对带宽为33．3％,最大带外抑制为-60dB。具有小体积、低插损、高抑制、宽阻带、易于加工等优点。     

114.3~123 GHz六阶带通滤波器设计

基于经典的半波长滤波器理论,设计了一种用于太赫兹通信系统的半波长磁耦合矩形波导带通滤波器。仿真结果表明,该滤波器中心频率为118 GHz,通带为114.3~123 GHz,相对带宽为7.4%;在131.8 GHz处的抑制度大于30 dB,通带插入损耗小于0.8 dB,通带回波损耗大于20 dB。经过实物测试,测试结果与仿真结果基本一致。这种滤波器的结构简单,制作难度低。     

110 GHz带通太赫兹滤波器设计

对滤波器的高精确度理论设计及小误差的工艺实现进行探讨与设计加工。总结了国内外的多种设计经验,讨论了多种类型的滤波器设计方案,选取适当的滤波器结构形式,设计加工了110 GHz的感性窗耦合波导滤波器,其中感性窗耦合结构采用传统机械加工技术实现,与法兰盘结构一并集成。基于高频结构仿真(HFSS)软件进行仿真,结果表明：设计并制作的110 GHz带通滤波器,其中心频率为110 GHz,相对带宽为5%,插入损耗小于1 dB,带内回波损耗大于 20 dB,距中心频率2倍带宽处,带外抑制大于40 dB。