Design of novel wideband reflective phase shifters with wide range of phase applications

This paper presents wideband compact differential reflective phase shifter based on the double layer slot-coupled coupler configuration. This novel phase shifter arrangement consists of a 3-dB hybrid coupler with the coupled and transmission ports terminated with rectangular and elliptically shaped microstrip loads. By altering the ports termination of the coupler, phase shifters propose differential phase ranging from −90° to +90° over 1.3–5.9G Hz frequency band. To achieve different range of phase performance, the proper reactance is calculated at the outputs of coupler. These reactances are transformed to the elliptical or rectangular-shaped microstrip load with various dimensions for every phase shifter. The calculation and simulations results show that the developed circuits could provide ±30°, ±60°, ±45° and ±90° differential phase shifts. For verification of this wideband phase shifter design method, two phase shifter example with rectangular and elliptical load termination is fabricated and measured. The measured return loss of the phase shifter with elliptically load is better than 10 dB over 1.3–5.9G Hz frequency band as well as insertion loss is less than 1 dB. The phase shift deviation is less than 2.1°. The results demonstrate that the proposed phase shifters are well suited for use in GPS/LTE/WiMax/WLAN frequency bands.     

基片集成波导正弦渐变槽单脉冲天线

为拓展工作带宽,以传统正反渐变槽天线为基础,利用基片集成波导馈电,该文提出了两种高增益、宽频带的正弦渐变槽天线。利用矩形波导3 dB定向耦合器和90移相器工作原理设计了半模基片集成波导单脉冲馈电网络,进而得到了对称型和非对称型正弦渐变槽单脉冲天线,带宽均超过了3.0 GHz,带内和波束最大增益在9.0 dBi左右,差波束零深在10.0 GHz处均低于-20 dB。其中,非对称型正弦渐变槽单脉冲天线具有更宽的工作频带和更平稳的天线增益,可以广泛应用于微波定向探测系统中。     

High Input Impedance NMOS-based Phase Shifter with Minimum Number of Passive Elements

In this paper, a new voltage-mode (VM) first-order phase shifter (all-pass filter) employing only four NMOS transistors and minimum number of passive elements (i.e. one resistor and one capacitor) is proposed. The proposed VM phase shifter has high input impedance and does not require passive element matching constraints. Moreover, since only two NMOS transistors are stacked between positive and negative supply voltages, the proposed circuit is suitable for low-voltage operation. Electronic tunability can be provided easily by replacing the employed resistor with an NMOS transistor operating in triode region. Simulation results based on 0.18 μm TSMC CMOS parameters with ±0.9 V supply voltages are given to demonstrate the performance of the proposed phase shifter.     

A low-power active inductor with improved Q-factor and its application to phase shifter

This letter presents a low-power single-ended active inductor with its Q-factor enhanced by feedback. Without sacrificing the self-resonance frequency and increasing the DC power consumption of the main circuit, the feedback transistor introduces a negative resistance; therefore, high Q-factors can be achieved in a wide operating frequency range. The proposed inductor was designed in a 0.13 μm CMOS process and simulated using Cadence Spectre. The active area is ~4 μm × 5 μm. With ~0.1 mW power consumption, the designed active inductor shows a 17 GHz maximum self-resonance frequency and a 1–8 GHz peak-Q operating frequency range. Using this active inductor, a 3-bit digitally-controlled phase shifter was designed. The phase shifter can provide a phase shift range larger than 180° from 1.5 to 4 GHz and a return loss better than 10 dB.     

基于微带双脊间隙波导技术的Ka波段六端口网络电路

面向毫米波高精度雷达探测应用,文中提出了一种基于微带双脊间隙波导技术的六端口网络电路。设计了基 于微带双脊间隙波导的功分器和耦合器电路,提出了微带双脊间隙波导至微带线的新型过渡转换结构,并基于简化的六 端口网络原理框图,将所设计的功分器、耦合器以及过渡转换结构进行有机组合,实现了所设计的Ka 波段六端口网络电 路。实验测试结果表明:在所设计的37.5 GHz~ 42.5 GHz 频率范围内,输入端口1 与四个输出端口间的相位差均 在±2.5°以内,输入端口2与四个输出端口间的相位差均在±5°内,工作中心频率处的输入输出间插入损耗约为7.3 dB。 实验与仿真结果吻合较好。     

Design,fabrication and characterization of miniature RF MEMS switched capacitor based phase shifter

This paper aims to present in detail the design, fabrication and the various characterization techniques adopted in realizing a novel miniature-size switched capacitor based phase shifter. The work strives to provide an all-round development of a DMTL (Distributed MEMS Transmission Line) based phase shifting unit yielding an overall phase shift of 15° at a frequency of 15 GHz. The RF MEMS (Radio Frequency Micro Electro Mechanical Systems) Switched Capacitor based phase shifter has highly miniaturized dimensions, and is capable of solving many limitations to which the conventional Switched Capacitors are mostly susceptible. This miniature RF MEMS switched capacitor actuates at a low actuation voltage of 12 V, exhibits a fundamental frequency of vibration as high as 1.468 MHz and a switching time of 1.4 µs which is an improvement over the other reported designs. Various characterization results seem to validate the simulations.     

An Ultra-Compact CMOS Variable Phase Shifter for 2.4-GHz ISM Applications

An ultra-compact monolithic microwave integrated circuit active variable phase shifter is proposed and implemented using CMOS technology. It is a reflective-type phase shifter consisting of a compact three-transistor active circulator and a second-order LC network. The use of an active inductor in the second-order LC network makes this phase shifter all active and ultra compact with a size of only 0.357 including bonding pads. The phase shifter was designed and demonstrated at 2.4 GHz and has a linear and continuously tunable range of 120 across the 2.4-GHz industrial-scientific-medical band.     

A dual six-port automatic network analyzer incorporating abiphase-bimodulation element

Current state-of-the-art dual six-port automatic network analyzers (ANAs) are dependent upon mechanical phase shifters and attenuators. Slow measurement and calibration are among the factors that have prevented six-port ANAs from more general use outside standards and research laboratories. Biphase bimodulation, a technique which removes the requirements for mechanical phase shifters or attenuators, is introduced. The technique provides improved sensitivity and elimination of drift as a consequence of AC modulation. A significant increase in measurement speed is achieved, allowing quasi-real-time evaluation of scattering parameters. An experimental prototype dual six-port ANA is described, and results obtained using the technique are given     

Graph Design of P-I-N Diode Phase Shifters(Short Paper)

A synthesis procedure of the impedance-transforming network in a p-i-n diode phase shifter is given. A representation of a reflection performance on the impedance plane is used successfully to determine the impedance matrix of the network. The procedure is straightforward and its validity is demonstrated by a prototype 90° phase shifter at 10 GHz.     

阻抗匹配器级数对铁电体移相器性能的影响

针对铁电体透镜式移相器的阻抗失配问题,分别采用3级、4级和5级的1/4波长阻抗匹配器结构,对铁电体移相器进行阻抗匹配调试仿真。通过对比不同匹配级数的匹配效果,最终确定了4级的匹配方案,并通过进一步优化器件结构,设计出的铁电体移相器在X频段内可实现360°相移,驻波比在主带宽内小于1.2,反射系数大于20 dB,中心频率处反射系数达到40 dB,信号传输系数在低频处小于1.1 dB,在高频处为1.5 dB,实现了铁电体移相器较好的阻抗匹配。     

X波段GaN五位数字移相器MMIC的设计

采用0.5μm GaN HEMT工艺设计了X波段五位数字移相器的单片微波集成电路(MMIC),描述了移相器的设计过程,并进行了版图电磁仿真。该移相器采用高低通滤波器型网络和加载线型结构。利用电路匹配技术设计移相器电路的开关结构,将GaN器件的插入损耗从14 dB降至1 dB。版图仿真结果表明,在9.2 GHz~10.2 GHz频带范围内,均方根移相误差小于3.5°,插入损耗典型值为17.4 dB,回波损耗小于-12 dB,版图尺寸为5.0 mm×4.7 mm。     

X波段4bit MMIC数字移相器的设计与实现

基于WIN 0.25 μm GaAs赝配高电子迁移率晶体管(PHEMT)工艺,设计并制备了一款X波段4 bit单片微波集成电路(MMIC)数字移相器.22.5°和45°移相单元采用开关滤波型拓扑结构,90°和180°移相单元采用高低通滤波型拓扑结构.对拓扑结构工作原理进行分析,并采用ADS2014软件完成电路的电磁仿真及优化.测试结果表明,该4 bit MMIC数字移相器获得了优良的宽带性能,且与仿真结果吻合良好.在8～ 13 GHz频带内,移相器的均方根(RMS)相位精度误差小于6.5°,插入损耗优于-6.8 dB,RMS插入损耗波动低于0.5 dB,输入回波损耗优于-13 dB,输出回波损耗优于-9.5 dB.该4 bit MMIC数字移相器在相对带宽为47％的X频段内性能优良,适用于有源相控阵雷达等通信系统中.     

Ultracompact reflective-type phase shifter MMIC at C-band with360° phase-control range for smart antenna combining

An ultracompact reflective-type monolithic microwave integrated circuit (MMIC) phase shifter is presented, fabricated using a commercial 0.6-μm GaAs MESFET process. The circuit has been developed for low-cost smart antenna receivers, operating in accordance to the IEEE 802.11a and the high-performance radio local area network (HIPERLAN) wireless network standards at C-band. Capacitance control, required for phase control, is performed by usual MESFETs with capacitance control ratios (C_max/C_min) of less than four. The impact of the reflective terminations on the maximum phase-control range and the corresponding loss is discussed. This investigation comprises single capacitive terminations, single resonated terminations, and terminations with two resonated loads-in parallel (DRL). With the DRL terminations, phase-control ranges of over 360° have been reached even with such limited capacitance control ranges. A transformation network is proposed for the DRL termination to reduce loss and loss variations. In this configuration, maximum signal losses of 9 and 3 dB, and 1-dB input compression points of higher than 2 and 8 dBm were measured for the phase shifter at 5.2 GHz within phase-control ranges of 360° and 90°, respectively. The branch-line coupler of the phase shifter has been realized by using lumped elements, thereby minimizing the circuit size. The total chip area is only 0.9 mm², which to our knowledge is the smallest size for a passive reflective-type phase shifter with 360° phase-control range reported to date     

An MMIC active phase shifter using a variable resonant circuit [andMESFETs]

This paper describes a monolithic-microwave integrated-circuit (MMIC) active phase shifter using a variable resonant circuit with a large amount of variable phase. We first propose a novel active phase-shifter configuration that uses a variable resonant circuit with second-order all-pass network characteristics. Phase can be changed with a constant amplitude by varying the capacitance or the inductance of the resonant circuit. Next, an experimental MMIC active phase shifter with input active matching is presented. A phase shift of over 100° and an insertion loss of 4±1 dB are obtained from 2.2 to 2.8 GHz. The chip size is less than 1.0 mm². Finally, an experimental 360° MMIC active phase shifter is presented. Over the bandwidth of 40 MHz at 2.44 GHz, the insertion gain is 2.0±0.7 dB and the phase error is within ±4° when measured in 30° steps     

An X-band 22.5°/45° digital phase shifter based on switched filter networks

The design approach and performance of a 22.5°/45°digital phase shifter based on a switched filter network for X-band phased arrays are described. Both the MMIC phase shifters are fabricated employing a 0.25μm gate GaAs pHEMT process and share in the same chip size of 0.82×1.06 mm². The measurement results of the proposed phase shifters over the whole operating frequency range show that the phase shift error is less than 22.5°±2.5°, 45°±3.5°, which shows an excellent agreement with the simulated performance, the insertion loss is within the range of 0.9-1.2 dB for the 22.5°phase shifter and 0.9-1.4 dB for the 45°phase shifter, and the input/output return loss is better than -12.5 and -11 dB respectively. They also achieve the similar P_1dB continuous wave power handing capability of 24.8 dBm at 10 GHz. The phase shifters show a good phase shift error, insertion loss and return loss in the X-band (40%), which can be employed into the wide bandwidth multi-bit digital phase shifter.     

C波段GaAs单片6位移相器

叙述了一种采用单片集成方式实现的Ｃ波段６位数字移相器的设计技术和研制结果。在ＨＰ－８５１０网络分析仪上的测试结果表明：在５．２～５．８ＧＨｚ频段，移相器插损为７．５±０．５ｄＢ，输入／输出驻波比好于１．５，均方根相移精度在５．５°以内。     

A Network Analyzer Incorporating Two Six-Port Reflectometers

This paper outlines the theory and design of a microwave network analyzer capable of measuring the network parameters of any linear reciprocal or nonreciprocal, active or passive two port. An RF signal from one source is applied at the same time to two six-port reflectometers which measure the incident and reflected waves at the ports of the two port being measured. An experimental dual six-port network analyzer for the 2-18-GHZ range has been completed and is described briefly. Some advantages of the proposed design over existing network analyzer designs are 1) only one source is needed, 2) no phase detectors are required, 3) no flexible cables or arms are used between the reflectometers and the two port being measured, and 4) self-calibration techniques are readily applied.     

A Dual Six-Port Network Analyzer Using Diode Detectors

The performance of a dual six-port network analyzer using diode detectors is described. The network analyzer operates over the 2-18-GHz band using commercially available low-barrier Schottky diodes. The paper describes the process for calibrating the diodes for deviation from square law. Measurement results are presented showing the accuracy and precision of tbe six-port network analyzer when measuring 1-port and 2-port devices. Key work attenuation measurements, automated network analyzer, impedance measurements, microwave network analyzer, network analyzer, and six-port.     

Measurement and calibration of a universal six-port networkanalyzer

A general theory of measuring multiport networks is presented. In order to measure microwave multiport networks conveniently a method involving the stepwise reduction of the order of the network under test is suggested. All formulas for calibrating and measuring the triple six-port network analyzer, which is a universal six-port network analyzer, are given without any ambiguity. The procedures for calibration and measurement are very simple. No standard three-port network is needed to calibrate the six-port system. Finally, the error caused by nonideal isolation is discussed     

Optimization of the Matching Network for a Hybrid Coupler Phase Shifter

A new theory is presented for how to find the optimum data for a transmission line used as a matching network for a hybrid coupler phase shifter. The theory gives a smaller phase-shift error and a greater bandwidth than already known methods. Two methods for equalization of the diode losses for a hybrid coupler phase shifter are described.