Single aperture monopulse horn antenna

This paper describes the design and performance of a conical Potter horn antenna which can generate sum or difference far field patterns suitable for monopulse tracking applications. The antenna consists of a horn antenna fed with a metal post loaded polarizer which is energised by suitably phased 50-/spl Omega/ matched coaxial probes. The prototype demonstrator designed here operates in the frequency range 8-8.6GHz with sum and difference patterns obtained by using a very simple phasing circuit. At 8.5GHz, the gain of the sum pattern is 18.6dB and the in the difference pattern is 26dB at boresight.     

适于毫米波应用的新型MEMS实时延时线(英文)

介绍了两种适于毫米波应用的RF MEMS实时延时线的设计。首先,在设计中采用了一种新颖的RF MEMS拓宽调节范围的变容器结构,得到了最大变容比为5.39的在片测试结果。其工艺设计基于表面微机械工艺,采用了由5个掩模版组成的工艺流程。然后,在RF MEMS变容器设计的基础上,完成了用于原理论证的Ka波段RF MEMS实时延时线的仿真设计、工艺流片和在片测试。Ka波段RF MEMS实时延时线的在片测试结果显示,在28GHz时处于下降状态的插入损耗为-2.36dB;两端口在28GHz时的回波损耗都小于-15dB,而在5～40GHz的整个测试频率范围内的回波损耗都小于-10dB。在Ka波段RF MEMS实时延时线设计基础上,60GHz RF MEMS实时延时线的仿真设计已经完成并准备投片。     

220-320 GHz Harmonic Mixer for a Full Band Sweep Vector Network Analyzer

This paper presents the design and characterization of a fixed tuned 220-320 GHz harmonic mixer employing commercial Schottky beam lead diodes in an antiparallel configuration. A diplexer provides distinct ports and matching for the subharmonic LO (26-40GHz) and the IF (20 MHz). The conversion loss was measured using a Gunn + tripler or quadrupler source calibrated with an absolute bolometer. We have built a 220-320 GHz full band sweep Vector Network Analyzer (VNA) using two WR3 waveguide couplers and three identical harmonic mixers (transmitter, reference, and receiver) pumped by two synthesizers (13-20GHz) followed by active doublers. The available dynamic range is 60 dBc/Hz over most of the band.     

On-chip micromachined solenoid balun for RF-SOC applications

A transformer balun is fabricated by using a post-CMOS compatible MEMS process. The novel concave-suspended solenoid balun can be integrated with radio-frequency system-on-chips (RF-SOCs). In the frequency range 0.5-10 GHz, the tested balun shows less than 0.7 dB amplitude imbalance and less than 1.5deg phase imbalance. After tuning, the transformer balun can match between a 100 Omega single-ended port and two 50 Omega differential ports. At the two differential ports, insertion losses of -1.5 and -0.8 dB are obtained at 5-GHz centre frequency, more than 40% bandwidth of S ₁₁ is achieved.     

Probe-fed circularly polarised monopulse radial line slot antenna

The design and performance of an annular slot planar circularly polarised array which generates sum or difference far-field patterns for monopulse tracking applications is described. The array consists of a radial waveguide the radiating elements of which consist of crossed slots designed to radiate right-hand circular polarisation in the frequency range 10.2 to 10.8 GHz. Sum and difference patterns are obtained by using a very simple phasing circuit. At 10.4 GHz the gain of the sum pattern is 12.3 dBi and the in the difference pattern is 28 dB at boresight.     

18GHz场效应放大器的实用设计

本文叙述在17.5～18GHz频带工作的低噪声场效应晶体管放大器之实用设计及其性能.放大器包括三级级联微带放大电路和波导输入/输出端口,获得了4.5dB的噪声系数和17dB的总增益.     

带状线宽带Wilkinson一分四功分器的设计

研究并设计了一种带状线宽带Wilkinson一分四功分器,实验结果显示,该功分器在6GHz～14GHz的宽频带范围内性能良好,其隔离度在整个频带范围内大于35dB,同时输入与输出端口均实现了良好的匹配且各输出口幅度相位一致性良好。     

Ka频段宽带双口双模馈源设计

针对卡塞格伦天线系统对馈源的要求,设计了一种Ka频段双口双模馈源,可与X频段馈源组合成体积较小的双频段馈源。采用圆环状的和差比较器结构,降低了双频段馈源的体积,通过添加过渡阶梯、圆柱销钉与金属调配板等设计,改善了双频段馈源的性能。测试结果表明,在绝对带宽2 GHz范围内,S和口、E差口与H差口驻波比均小于2,3个端口间的隔离度均大于25 dB。测试频率的和方向图在±60°时的归一化增益均在-14~-20 dB范围内,初级归一化和方向图的对称性较理想,差方向图的零值深度均小于-25 dB,满足卡塞格伦天线对馈源设计的指标要求。     

10?30 GHz monolithic GaAs travelling-wave divider/combiner

A four-way monolithic GaAs travelling-wave power divider/combiner has been designed, fabricated and evaluated. With a design centre frequency of 20 GHz, a bandwidth of from 10 GHz to 30 GHz has been measured. The insertion loss per dividing or combining action is less than 0.5 dB, with isolation between ports no worse than 20 dB. The input/output VSWRs are better than 2:1 across the same band. This divider/combiner can readily be used with monolithic GaAs power FET amplifiers to produce a several-fold increase in output powers over the 10 to 30 GHz frequency range.     

3 mm二倍频器的设计与实现

设计了一种W波段二倍频器,输入为46～48 GHz,输出为92～96 GHz,用来为毫米波接收前端系统提供3 mm本振信号.二倍频器采用微带线制作,且输入和输出端口位于腔体轴向两侧,选择对脊鳍线过渡来完成波导-微带的过渡结构.采用电磁场电路设计软件ADS,大大提高了毫米波电路设计的效率和准确度.测试结果表明,在输出92～96 GHz频带范围内,倍频损耗在22 dB以内.基波和三次谐波的抑制大于24 dB.该二倍频器符合工程使用的标准,同时其设计过程也表明了计算机辅助设计在毫米波电路设计方面是非常有价值的,可以大大提高工作效率.     

Ultra-Wideband Power Divider With Good In-Band Splitting and Isolation Performances

An ultra-wideband (UWB) power divider on microstrip line is proposed, analyzed and designed. This divider is formed by installing a pair of stepped-impedance open-circuited stubs and parallel-coupled lines to two symmetrical output ports. In addition, a single resistor is properly placed between two output ports. After simple transmission line theory analysis, it is demonstrated that 3 dB power splitting from one input to two output ports, good impedance matching at all the three ports and excellent isolation between two output ports are achieved over the specified 3.1–10.6 GHz UWB range. Finally, a prototype divider is fabricated and measured to provide an experimental verification on the predicted attractive features.      

L波段紧凑型平面三路功率合成器设计

提出了一种平面结构的L波段三路功率合成器,通过两节三路四分之一波长阻抗变换器与平面隔离电阻构成的微带电路实现。合成器使用仿真软件优化计算结果并得到最终设计。测试结果与仿真结果吻合：在1.1GHz至1.7GHz带宽内,各个端口驻波比小于1.13;输入端口间隔离度大于25dB;合成效率大于94.5％且最大幅度不平坦度小于0.05dB。这种功率合成器结构紧凑,性能达到设计要求。     

Design of a Compact UWB Out-of-Phase Power Divider

The design of a compact out-of-phase uniplanar power divider operating over an ultra wide frequency band is presented. To achieve an out-of-phase signal division over a large frequency range, a T-junction formed by a slotline and a microstrip line accompanied by wideband microstrip to slotline transitions is employed. The simulated and experimental results of the developed divider show a low insertion loss and good return loss performance of the three ports across the band 3.1-10.6 GHz     

A PCB-compatible 3-dB coupler using microstrip-to-CPW via-hole transitions

A 3-dB coupler by implementing microstrip-to-coplanar waveguide (CPW) via-hole transitions is proposed. The proposed coupler, with the advantages of wider coupled line widths and spacing without using any bonding wires, can eliminate the uncertain factors of conventional Lange couplers caused by the printed circuit board (PCB) manufacturing processes. The proposed coupler can be easily fabricated on a single-layer PCB substrate instead of using multilayer substrates. Good agreements between the simulation and the measurement in the frequency range from 0.45 to 5 GHz can be achieved. The measured results at the center frequency of 2.4 GHz have the return loss better than -15dB; the insertion loss of coupled and direct ports is about 3/spl plusmn/ 0.2dB and the relative phase difference of 89/spl plusmn/0.3/spl deg/. The dimension of the coupler is 3.1cm /spl times/ 1.8cm.     

Two-port hybrid ring dipole with simultaneous sum and difference element patterns

The design of a two-port dipole that is fed by a hybrid ring is described. The two dipole ports provide simultaneous sum and difference element patterns. A prototype element was designed and fabricated. The input return loss for the two ports and isolation between ports was greater than 15 dB. The sum and difference patterns were verified by measurements in an anechoic chamber.     

A new wide-band planar balun on a single-layer PCB

A new wide-band microstrip balun implemented on a single-layer printed circuit board (PCB) is presented in this letter. The proposed planar balun consists of a wide-band Wilkinson power divider and a noncoupled-line broad-band 180/spl deg/ phase shifter. To demonstrate the design methodology, one prototype is realized. The new design was simulated and validated by the measurement. Measured results show that 10-dB return loss of the unbalanced port has been achieved across the bandwidth from 1.7 GHz to 3.3 GHz, or 64%. Within the operation band, the measured return losses for both the two balanced ports are better than -10 dB, and the balanced ports isolation is below -1.5 dB. The measured amplitude and phase imbalance between the two balanced ports are within 0.3 dB and /spl plusmn/5/spl deg/, respectively, over the operating frequency band.     

Wide-band RF photonic second order vector sum phase-shifter

A novel technique to extend the phasing range of the vector sum phase shifter by exploiting its second order response is proposed and implemented. A continuously variable phase shift is demonstrated between 8 and 16 GHz with phasing range exceeding 450/spl deg/ measured at 16 GHz. Good agreement between the predictions and measurements has been obtained.     

基于耦合腔的太赫兹垂直传输结构

提出了一种工作在110 GHz的耦合腔垂直传输结构。在垂直金属腔的两端对称地装配两个模式变换单元,作为波导的两个激励端口。模式变换单元在50 μm厚度石英基片上实现,该基片采用通孔结构和双面镀金工艺。因此,该垂直传输结构在太赫兹频段具有较低的插入损耗。仿真结果与测试结果拟合良好,模式变换单元的 S₂₁仿真结果为?0.7 dB,测试结果小于?1.3 dB,在105~116 GHz带宽的反射系数低于?10 dB。     

9.6/4.8 GHz dual-mode voltage-controlled oscillator with injection locking

A prototype dual-mode voltage-controlled oscillator supporting two simultaneous oscillation modes is fabricated and demonstrated in a 0.18 mum CMOS process. The oscillator has two resonant ports while sharing one bias. Injection locking is applied to lock the low frequency, 4.8 GHz, to half of the high frequency, 9.6 GHz. The oscillator core consumes 7 mA from a 1.8 V supply. Measurement shows a tuning range of 5% and phase noise is -103 and -109 dBc/Hz measured at 1 MHz offset from the high and low frequency tones, respectively     

Design and Performance of Microwave Amplifiers with GaAs Schottky-Gate Field-Effect Transistors

The design and performance of an X-band amplifier with GaAs Schottky-gate field-effect transistors are described. The amplifier achieves 20 /spl plusmn/ 1.3-dB gain with a 5.5-dB typical noise figure (6.9 dB maximum) over the frequency range of 8.0-12.0 GHz. The VSWR at the input and output ports does not exceed 2.5:1. The minimum output power for 1-dB gain compression is +13 dBm, and the intercept point for third-order intermodulation products is +26 dBm. The design of practical wide-band coupling networks is discussed. These networks minimize the overall amplifier noise figure and maintain a constant gain in the band.