多频段背腔式半模基片集成波导弯折缝隙天线

针对需要安装在金属平台上的天线应用,提出了一种具有定向辐射特性的新型多频段背腔式半模基片集成波导缝隙天线。利用半模基片集成波导谐振腔的多模式特性实现了该天线多频段工作,通过在谐振腔的金属顶面蚀刻弯折形状的缝隙实现对外辐射,并可以通过调整弯折缝隙尺寸参数来减小天线尺寸。仿真和测试结果表明,该天线能同时工作在5.7/10.7/11.9/12.5/13.1GHz,且在这5个频段的最低增益大于6.7 dBi。天线具有便于和平面电路集成、体积小、结构简单、成本低等优点,具有一定的工程应用价值。     

一种新型半模基片集成波导三孔定向耦合器

半模基片集成波导(HMSIW)是近年来出现的一种高性能平面导波结构,具有传输损耗小、功率容量大、易于集成等优点,已开始广泛应用于微波无源器件的设计中。文章基于HMSIW技术与PCB工艺技术设计制作了一种新颖的三孔定向耦合器,通过在耦合孔上金属面蚀刻"工"字形槽增加孔的耦合量。设计的HMSIW三孔定向耦合器不仅保持了集成基片波导(SIW)定向耦合器的所有优点,而且在面积上减小了近50﹪,工作带宽拓展到1GHz。实测数据与仿真结果基本吻合,验证了设计方法的正确性与可行性。     

Characterization of the Propagation Properties of the Half-Mode Substrate Integrated Waveguide

The propagation properties of the half-mode substrate integrated waveguide (HMSIW) are studied theoretically and experimentally in this paper. Two equivalent models of the HMSIW are introduced. With the first model, equations are derived to approximate the field distribution inside and outside the HMSIW. Using the second model, an approximate closed-form expression is deduced for calculating the equivalent width of an HMSIW that takes into account the effect of the fringing fields. The obtained design formulas are validated by simulations and experiments. Furthermore, the attenuation characteristics of the HMSIW are studied using the multiline method in the frequency range of 20–60 GHz. A numerical investigation is carried out to distinguish between the contributions of the conductive, dielectric, and radiation losses. As a validation, the measured attenuation constant of a fabricated HMSIW prototype is presented and compared with that of a microstrip (MS) line and a substrate integrated waveguide (SIW). The SIW is designed with the same cutoff frequency and fabricated on the same substrate as the HMSIW. The experimental results show that the HMSIW can be less lossy than the MS line and the SIW at frequencies above 40 GHz.      

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.     

Quasi-optical planar arrays with FETs and slots

This work describes the design concept and experimental results for prototypes of two-dimensional quasi-optical power-combining arrays. Several different quasi-optical circuits were used to obtain the fundamental data for this study. How to incorporate the antenna input impedance into the active antenna circuit and how to analyze the strong coupling condition with two operating modes are addressed using large-signal analysis. Several circuit configurations are demonstrated, including a single active antenna operating at 9.3 and 24.0 GHz, a six-element linear power-combining array operating at 15.6 GHz, and four-element and sixteen-element two-dimensional power combining arrays operating at 10.4 and 7.8 GHz. Important characteristics such as antenna patterns and tuning ranges are discussed. The prospects for a two-dimensional monolithic quasi-optical power-combining array are discussed     

A Millimeter Wave Six-Port Network Using Half-Mode Substrate Integrated Waveguide

A novel six-port network based on half-mode substrate integrated waveguide (HMSIW) is proposed. In this design, a HMSIW hybrid 3 dB coupler and a -90° phase shifter are designed as fundamental building block of six-port network. By combining four HMSIW couplers and one phase shifter, a HMSIW six-port network at 29–32 GHz is constructed. The six-port network is fabricated and measured. Measurement results agree well with simulation, and show good balance and phase relationship between ports.     

Full Band Millimeter-Wave Power-Combining Amplifier Using a Lossy Power-Combining Network

This paper presents a millimeter-wave broadband power-combining amplifier using a novel lossy waveguide-based power combiner. The lossy combiner has a performance of broadband low-loss combining symmetrically and has properties of good match and high isolation at and between ports, because lossy planar lines are embedded in the lossy combiner and even-mode excitations are weakened. The measured results show that the lossy combiners has a loss of about 0.14 dB and achieves reflection and isolation of about—15 dB in 26.5–40 GHz. And then, using the lossy combiner, a compact lossy waveguide-based four-way-combining network is fabricated. The lossy network has a measured loss of about 0.25 dB and achieves good improvements of match and isolation in the full Ka-band. The improvements can enhance stability of amplifying units when the lossy combining network used in multi-way power-combining amplifier. Using the lossy combining network, a solid-state power-combining amplifier is developed, and corresponding experimental results show that output power is more than 30 dBm and combining efficiency is more than 80 % in the full Ka-band.     

A Ka-band power amplifier based on the traveling-wave power-dividing/combining slotted-waveguide circuit

An eight-device Ka-band solid-state power amplifier has been designed and fabricated using a traveling-wave power-dividing/combining technique. The low-profile slotted-waveguide structure employed in this design provides not only a high power-combining efficiency over a wide bandwidth, but also efficient heat sinking for the active devices. The measured maximum small-signal gain of the eight-device power amplifier is 19.4 dB at 34 GHz with a 3-dB bandwidth of 3.2 GHz (f/sub L/=31.8 GHz, f/sub H/=35 GHz). The measured maximum output power at 1-dB compression (P/sub out/ at 1 dB) from the power amplifier is 33 dBm (/spl sim/2 W) at 32.2 GHz, with a power-combining efficiency of 80%. Furthermore, performance degradation of this power amplifier due to device failures has also been simulated and measured.     

Grid oscillators

Loading a two-dimensional grid with active devices offers a means of combining the power of solid-state oscillators in the microwave and millimeter-wave range. The grid structure allows a large number of negative resistance devices to be combined. This approach is attractive because the active devices do not require an external locking signal, and the combining is done in free space. In addition, the loaded grid is a planar structure amenable to monolithic integration. Measurements on a 25-MESFET grid at 9.7 GHz show power-combining and frequencylocking without an external locking signal, with an ERP of 37 W. Experimental far-field patterns agree with theoretical results obtained using reciprocity.     

Grid oscillators

Loading a two-dimensional grid with active devices offers a means of combining the power of solid-state oscillators in the microwave and millimeter-wave range. The grid structure allows a large number of negative resistance devices to be combined. This approach is attractive because the active devices do not require an external locking signal, and the combining is done in free space. In addition, the loaded grid is a planar structure amenable to monolithic integration. Measurements on a 25-MESFET grid at 9.7 GHz show power-combining and frequencylocking without an external locking signal, with an ERP of 37 W. Experimental far-field patterns agree with theoretical results obtained using reciprocity.     

一种结构紧凑性能优良的微波功率合成系统

为了满足大功率微波系统的需求,本文提出了一种复合式功率合成系统的设计方法。基于此方法,利用CST2019软件设计了一款16路Ku波段功率合成系统。该合成系统的尺寸为48 mm×214 mm×18 mm。测试结果显示从14.5 GHz到17.5 GHz范围内,其无源合成效率可达90%以上。该合成系统由矩形波导合成系统和波导同轴型合成系统构成,具有双层支路,结构紧凑,呈准平面,非常有利于散热装置的安装。     

Millimeter-Wave Power Amplifier Based on Coaxial-Waveguide Power-Combining Circuits

A millimeter-wave power amplifier based on a coaxial-waveguide power-combining circuit is presented in this paper. A coaxial stepped impedance transformer is used to provide an impedance transition from the 50- $Omega$ input coaxial line to the oversized coaxial waveguide, and its equivalent-circuit model has also been developed. A Ka-band four-device coaxial-waveguide power amplifier is fabricated and tested. The 10-dB return loss bandwidth of the fabricated amplifier is from 27.5 to 40 GHz, and the power amplifier has 17–25.9 dB gain over a wide bandwidth from 26 to 38 GHz. The measured output power at 1-dB gain compression is about 26.6 dBm at 30 GHz, with a power-combining efficiency of about 90%.      

V-band high-efficiency broadband power combiner and power-combining module using double antipodal finline transitions

A V-band high-efficiency power-combining module was developed using double antipodal finline structures. The combiner performs the dual functionality of power combining and mode transition from microstrip to waveguide. The measurement of the back-to-back connected combiner demonstrated an insertion loss of 1.2 dB and return loss better than 15 dB around 60 GHz with a 3 dB bandwidth of 18 GHz. The power-combining module incorporating two MMIC power amplifiers demonstrated a combining efficiency higher than 80%.     

Active inverted stripline circular patch antennas for spatial powercombining

An active antenna configuration is proposed for spatial-power-combining applications. The active patch antenna uses an inverted stripline topology to take advantage of several features. These features include avoiding drilling through the circuit substrate to insert the diode and the use of air within the resonant cavity to reduce loss. The inverted substrate serves as a radome for hermetic sealing. The active antenna and housing can be fabricated in modular form for reduced cost and easy replaceability of devices. The active inverted stripline patch antenna exhibits a much cleaner spectrum and greater stability than previously reported active antennas. The fixture serves as a ground plane, heat sink, and support in an active planar array or as a mirror in a quasi-optical power-combining resonator. A single active antenna operating at 9.23 GHz exhibited a 16-MHz locking bandwidth at 30-dB locking gain. Power-combining efficiencies of over 89% have been demonstrated for a four-element square array that maintained injection-locking and power-combining over a 60-MHz bias tuned bandwidth. Similarly, a four-element diamond array showed over 86% combining efficiency and 50-MHz bias tuned bandwidth. Beam steering was demonstrated by varying bias voltage to the individual antenna elements of the square array     

毫米波高效率三路功率合成放大器

基于波导双边耦合电桥与波导-鳍线-微带过渡,提出了一种非2ⁿ路功率合成方法,并按照该方式在毫米波频段设计出了一种高效率的3 路功率合成电路。实测结果表明,25 ~31GHz 频率范围内的无源合成效率高于89%。采用该电路将3 只TGA4505 放大单片合成后构成的功率合成放大器,在25 ~31GHz 频率范围内得到了最大12W 的饱和功率输出,饱和附加效率最高可达20%。     

Narrowband amplifier with excellent power combining efficiency

Based on a coaxial waveguide power-dividing/combining circuit, a four-device solid-state power amplifier with excellent power combining efficiency is presented. The fabricated power amplifier combining four monolithic microwave integrated circuit power amplifiers shows a 13-16.65 dB small-signal gain over a wide bandwidth of 7-13.5 GHz. The measured maximum output power at 1 dB compression is 25.4 dBm at 11 GHz, with a power-combining efficiency of 91%.     

Integrated active antenna array using unidirectional dielectricradiators

In this paper, design considerations and experimental investigations of an integrated active antenna for space power combining that makes use of unidirectional dielectric radiators (UDRs) are presented and discussed. Attractive electrical performance stemming from proprieties of nonradiating dielectric waveguide structures is used to design a prototype at a frequency of 14 GHz. A UDR feed circuit is implemented by microstrip lines and aperture-coupling is studied experimentally for arrays of two, four and eight radiators. Measurements show high coupling and radiation efficiencies of the proposed excitation method. A power-combining efficiency of 89% was measured and a gain of 23.1 dBi was achieved for an antenna with eight radiators and four amplifiers. It is also shown that such a circuit configuration allows the combination of planar Ku-band monolithic hybrid microwave integrated circuit and UDR components in flexible design of active array antennas     

A High-Power $Ka$-Band (31–36 GHz) Solid-State Amplifier Based on Low-Loss Corporate Waveguide Combining

A method of using low-loss waveguide septum combiners is developed into a high-power $Ka$-band (31–36 GHz) amplifier producing $>$50 W at 33 GHz ($Ka$-band) using 32 low-power ($≪$2 W) solid-state amplifier modules. By using low-loss waveguide combining and a packaged monolithic microwave integrated circuit with a low-loss microstrip-to-waveguide launcher, the output loss is minimized, allowing for the overall power-combining efficiency to remain high, $>$80% (average insertion loss of combiner $≪$ 0.7 dB and average insertion loss of launcher $≪$0.3 dB) over 31–36 GHz. In the past, lower power-combining efficiencies have limited the number of modules that can be combined at $Ka$ -band, and hence, have limited the power output. The approach demonstrated in this paper, with high power-combining efficiency, allows a very large number (32) of solid-state amplifier modules to be combined to produce high powers. Greater than 50 W was demonstrated with low power modules, but even higher powers $>$120 W are possible. The current approach is based on corporate combining, using low-loss waveguide septum combiners that provide isolation, maintaining the true graceful degradation of a modular solid-state amplifier system.      

毫米波高密度脉冲功率合成放大器设计

提出一种新颖的多层结构功率合成方法,具有密度高、插入损耗小的优点。相比传统双面合成方案,该技术在同样体积内理论上可将合成路数扩展1倍,实现输出功率增长3 dB,因而非常适合应用在对功放体积、重量有严格限制的平台中。通过对该高密度功率合成电路进行理论分析与仿真优化,在8 mm波段设计了一个具有4层电路形式的2×4路功率合成放大器。无源实测结果显示,30~37 GHz频率范围内的合成效率高于91%。放大器采用8只典型输出功率16 W的GaN MMIC单片合成,按35μs脉宽、10%占空比条件进行有源测试,在34~36 GHz频率范围内得到了最小123 W的功率输出,功率增益大于14.9 dB,功率附加效率高于21.7%。     

半模基片集成波导带通滤波器的设计与实现

简要介绍半模基片集成波导这一新技术,设计了一个中心频率为35GHz,相对带宽为23％的基片集成波导带通滤波器,CST的数值计算结果显示该途径是成功的.