A 23–37 GHz Miniature MMIC Subharmonic Mixer

A novel configuration of subharmonic mixer using an anti-parallel diode pair is presented for operating over the 23-37 GHz band. The monolithic microwave integrated circuit is implemented by GaAs 0.15 mum PHEMT technology with the compact size of 0.85 times 0.85 mm². This mixer employs a directional coupler, LC low-pass filter, and a short stub for isolating three ports corresponding to radio frequency (RF), local oscillation (LO) input, and intermediate frequency (IF) output ports. The directional coupler also provides impedance transformation between the diode pair, RF, and LO ports. This makes the subharmonic mixer more compact and flexible. The best conversion loss of the subharmonic mixer is 9.4 dB, and the LO-to-RF and LO-to-IF isolations are better than 22 and 31 dB, respectively.     

基于载波抑制单边带调制的微波光子混频方案

为了克服电混频器的瓶颈,实现大带宽的信号混频,提出了一种基于双偏振双平行马赫-曾德尔调制器的微波光子混频方案。通过调节调制器的6个直流偏置电压进行载波抑制单边带调制,射频(RF)信号和本振(LO)信号分别注入调制器,相互隔离,各自调制,且在2个相互正交的偏振态上传输,最后经偏振控制器和检偏器调整到同一偏振态上进行拍频,上、下变频模式的切换只需要改变其中一个直流偏置电压。仿真与实验表明:该方案切实可行,输入的RF频率在11~25 GHz时,输出的上变频或下变频信号的RF杂散抑制比不低于25 dB,频谱纯度高,可调谐性好,变频模式之间切换方便,系统的RF/LO隔离度达到-49 dB。     

Wide-band balanced active HEMT mixer

The design and characteristics of a balanced active high electron-mobility transistor (HEMT) mixer operating in the 4.5-10-GHz frequency band are described in this paper. It consists of two parts implemented as independent hybrid circuits, namely, an microwave part fabricated by using a uniplanar technology and comprising a 180° hybrid ring coupler, HEMTs, and input-output matching circuits, and a low-frequency part consisting of an L-C balun and a low-pass filter built of discrete elements. The design of the microwave part of the mixer ensures a high degree of isolation between the signal and local-oscillator (LO) inputs within a wide frequency band at low IF. The measurements show a conversion gain of 5-7 dB, noise figure of 5-7.5 dB, and isolation between the signal and LO ports greater than 20 dB within the 4.5-10-GHz range     

60 GHz MMIC double balanced Gilbert mixer in mHEMT technology with integrated RF, LO and IF baluns

A 60 GHz MMIC double balanced Gilbert mixer (DBGM) with integrated RF, LO and IF baluns has been designed, fabricated in an mHEMT MMIC technology and characterised with probed measurements. Although a standard mixer topology for integrated circuits in the low gigahertz region, the DBGM has had very little impact in the millimetre-wave range. To the authors' knowledge, the presented DBGM operates at the highest RF frequency ever published for any FET-based Gilbert type mixer, double or single balanced. A measured down conversion gain of 1.5 dB at 60 GHz is obtained with a DC power consumption of 300 mW. Further, IF bandwidth, isolation between the LO, RF and IF ports, 1 dB compression point for the RF input, and LO input power is presented     

基于光子芯片的微波光子混频器 （特邀）

提出了一种由光生本振单元和波长分离调制单元组成的微波光子混频方法,并在绝缘体上硅材料上设计实现了上述波长分离调制芯片。该芯片集成了硅基相位调制器、微环滤波器、光电探测器、光耦合器和光栅耦合器。实验搭建了基于该波长分离调制芯片的微波光子次谐波混频系统,结果表明,该微波光子混频器可以将6~16 GHz的RF信号变频到33~23 GHz。此外,针对实验系统中残留的混频杂散,分别提出了增加微环滤波器抑制比降低泄露光生本振强度和引入光移相器修正泄漏光生本振相位两种解决方案。通过仿真验证可知,引入光移相器的方法更为简单,更适合于光子集成芯片。     

InAlAs/InGaAs HBT X-band double-balanced upconverter

We report on an InAlAs/InGaAs HBT Gilbert cell double-balanced mixer which upconverts a 3 GHz IF signal to an RF frequency of 5-12 GHz. The mixer cell achieves a conversion loss of between 0.8 dB and 2.6 dB from 5 to 12 GHz. The LO-RF and IF-RF isolations are better than 30 dB at an LO drive of +5 dBm across the RF band. A pre-distortion circuit is used to increase the linear input power range of the LO port to above +5 dBm. Discrete amplifiers designed for the IF and RF frequency ports make up the complete upconverter architecture which achieves a conversion gain of 40 dB for an RF output bandwidth of 10 GHz. The upconverter chip set fabricated with InAlAs/InGaAs HBT's demonstrates the widest gain-bandwidth performance of a Gilbert cell based upconverter compared to previous GaAs and InP HBT or Si-bipolar IC's     

K-Band Integrated Double-Balanced Mixer

A novel microwave integrated circuit (MIC) double-balanced mixer with good isolation between the three ports is described. The mixer is fabricated using a combination of microstrip lines, slotlines, and coupled slotlines, together with four beam-lead Schottky-barrier diodes. The K-band magic-T has been developed for the double-balanced mixer. The minimum conversion loss measured at a signal frecuency of 19.6 GHz is 4.7 dB. Isolation between RF and LO ports is greater than 20 dB from 18 to 21 GHz. The mixer can be expected to have wide applications in MIC receivers and transmitters up to the millimeter-wave band.     

60-GHz monolithic down- and up-converters utilizing asource-injection concept

This paper deals with the design considerations, fabrication process, and performance of coplanar waveguide (CPW) heterojunction FET (HJFET) down- and up-converter monolithic microwave integrated circuits (MMIC's) for V-band wireless system applications. To realize a mixer featuring a simple structure with inherently isolated ports, and yet permitting independent port matching and low local oscillator (LO) power operation, a “source-injection” concept is utilized by treating the HJFET as a three-port device in which the LO signal is injected through the source terminal, the RF (or IF) signal through the gate terminal, and the IF (or RF) signal is extracted from the drain terminal. The down-converter chip incorporates an image-rejection filter and a source-injection mixer. The up-converter chip incorporates a source-injection mixer and an output RF filter. With an LO power and frequency of 7 dBm and 60.4 GHz, both converters can operate at any IF frequency within 0.5-2 GHz, with a corresponding conversion gain within -7 to -12 dB, primarily dominated by the related filter's insertion loss. Chip size is 3.3 mm×2 mm for the down-converter, and 3.5 mm×1.8 mm for the up-converter     

Balanced subharmonic mixers for retrodirective-array applications

The drawback of conventional Pon retrodirective antenna systems is the requirement of a local oscillator (LO) working at approximately twice the receive frequency. This limits the use of these systems to rather moderate frequencies where such an oscillator can be obtained. To overcome this problem, a new phase conjugate mixer topology is proposed, whereby the use of a harmonic mixer instead of the conventional fundamental type effectively halves the LO frequency requirement. Another significant problem of conventional Pon phase conjugate mixers is the small spacing in frequency, typically only a few 0.1% of the carrier frequency, between RF, IF, and LO frequency. In this paper, we have overcome this problem by introducing a double balanced structure with a novel phasing strategy. The phasing circuit automatically cancels the RF and LO signal at the system's output port, giving 36-dB RF/IF, and 34-dB LO/IF isolation for a 970-MHz IF and 990-MHz RF signal. The new mixer structure proposed here is an attractive proposition for use in retrodirective antenna arrays significantly enhancing their potential for application in the millimeter-wave frequency range     

A 26-GHz Band Integrated Circuit of a Double-Balanced Mixer and Circulators

Integration of a double-balanced mixer and ferrite-disk type circulators have been successfully achieved in the 26-GHz band. The total single-sideband noise figure of the integrated circuit, composed of a mixer and two circulators, is 8.5 dB, including the noise contribution from an IF amplifier. The double-balanced mixer is composed of microstrip lines, slot lines, coupled slot lines, coplanar lines, Au wires, and four beam lead Schottky-barrier diodes. The minimum conversion loss of the mixer is 5.3 dB at a signal frequency of 25.4 GHz. Isolation between RF and LO ports is greater than 30 dB. The ferrite-disk type circulator is produced by a newly developed precise machining technique. The minimum insertion loss of the circulator is 0.45 dB, and the isolation is greater than 20 dB. The integrated circuit with the ferrite-disk type circulators will be extended to the millimeter-wave band.     

RF and IF ports matching circuit synthesis for a simultaneousconjugate-matched mixer using quasi-linear analysis

A quasi-linear two-port approach between RF and IF ports to design a simultaneous conjugate-matched mixer is presented in this paper. Conventionally, mixer design is treated as a nonlinear three-port device problem. Nonetheless, with the exception of the large-signal local oscillator (LO) that exists at the LO port, the input RF and output IF signals that exist at the RF and IF ports, respectively, are small signals. Consequently, mixers can be approximated as bilateral quasi-linear two-port circuits with a time-variant transfer function between the RF and IF ports, in which the LO port of the mixer is treated as part of the two-port network. With this approximation, it can be shown mathematically that the optimum source and load matching networks required for attaining simultaneous conjugate match at the RF and IF ports are actually time invariant, thus implying that it is possible to synthesize these optimum impedance values. This proposed mixer design technique, together with the equations derived, are verified with block-diagram simulation and experimental measurements of two 2.4-GHz RF/420-MHz IF double-balanced diode mixers     

2D phase-conjugated retrodirective array with information carrying capability

A new two-dimensional (2D) phase-conjugated retrodirective array with star-shaped antenna elements is proposed. The phase conjugators provide high isolation of -48 dB between RF and IF ports when RF/IF signals share the same ports in a balanced hybrid. By on-off keying modulation of the local oscillator (LO), the new 2D phase-conjugated retrodirective array can reflect the signal back to the interrogator with the modulation signal carried on it for information exchange. Experimental results show that this array can achieve 2D retrodirectivity within 120deg angle of wide scan range at arbitrary signal polarisation and injection direction     

A CMOS Ku-Band 4x Subharmonic Mixer

In this work, the design and measurement of a new 4x subharmonic mixer circuit is presented using CMOS 0.18 m technology. With an RF input signal at 12.1 GHz, and an LO signal at 3.0 GHz, an intermediate frequency of 100 MHz is produced (f_IF = f_RF - 4f_LO). The mixer uses a modified Gilbert-cell topology with octet-phase LO switching transistors to perform the quadruple subharmonic mixing. Included in the design is an active balun for the RF signal and a circuit that generates an octet-phase LO signals from a differential input. The mixer has a conversion gain of approximately 6 dB, 1-dB compression point of -12 dBm, IIP3 of -2 dBm, and IIP2 of 17 dBm. The circuit also exhibits excellent isolation between its ports (e.g. LO-RF: 71 dB, 4LO-RF: 59 dB).     

宽中频CMOS下变频器单片

该文介绍了一种工作于毫米波频段的宽中频(IF)下变频器。该下变频器基于无源双平衡的设计架构,片上集成了射频(RF)和本振(LO)巴伦。为了优化无源下变频器的增益、带宽和隔离度性能,电路设计中引入了栅极感性化技术。测试结果表明,该下变频器的中频带宽覆盖0.5～12 GHz。在频率为30 GHz、幅度为4 dBm的LO信号驱动下,电路的变频增益为–8.5～–5.5 dB。当固定IF为0.5 GHz、LO幅度为4 dBm时,变频增益随25～45 GHz的RF信号在–7.9～–5.9 dB范围内变化,波动幅度为2 dB。LO-IF, LO-RF, RF-IF的隔离度测试结果分别优于42, 50, 43 dB。该下变频器芯片采用TSMC 90 nm CMOS工艺设计,芯片面积为0.4 mm2。     

A 9–31-GHz Subharmonic Passive Mixer in 90-nm CMOS Technology

A subharmonic down-conversion passive mixer is designed and fabricated in a 90-nm CMOS technology. It utilizes a single active device and operates in the LO source-pumped mode, i.e., the LO signal is applied to the source and the RF signal to the gate. When driven by an LO signal whose frequency is only half of the fundamental mixer, the mixer exhibits a conversion loss as low as 8–11 dB over a wide RF frequency range of 9–31GHz. This performance is superior to the mixer operating in the gate-pumped mode where the mixer shows a conversion loss of 12–15dB over an RF frequency range of 6.5–20 GHz. Moreover, this mixer can also operate with an LO signal whose frequency is only 1/3 of the fundamental one, and achieves a conversion loss of 12–15dB within an RF frequency range of 12–33 GHz. The IF signal is always extracted from the drain via a low-pass filter which supports an IF frequency range from DC to 2 GHz. These results, for the first time, demonstrate the feasibility of implementation of high-frequency wideband subharmonic passive mixers in a low-cost CMOS technology.     

一款集成驱动放大器的低变频损耗混频器设计

采用0.5μm GaAs工艺设计并制造了一款单片集成驱动放大器的低变频损耗混频器.电路主要包括混频部分、巴伦和驱动放大器3个模块.混频器的射频(RF)、本振(LO)频率为4～7 GHz,中频(IF)带宽为DC～2.5 GHz,芯片变频损耗小于7 dB,本振到射频隔离度大于35 dB,本振到中频隔离度大于27 dB.1 dB压缩点输入功率大于11 dBm,输入三阶交调点大于20 dBm.该混频器单片集成一款驱动放大器,解决了无源混频器要求大本振功率的问题,变频功能由串联二极管环实现,巴伦采用螺旋式结构,在实现超低变频损耗和良好隔离度的同时,保持了较小的芯片面积.整体芯片面积为1.1 mm×1.2 mm.     

毫米波宽带高中频单平衡混频器设计与实现

针对毫米波宽带通信、雷达和测试仪器领域的应用需求,提出一种E波段宽带高中频(IF)单平衡混频器。射频(RF)及本振(LO)信号通过多分支宽带加宽波导正交耦合器输入,通过鳍线过渡结构将信号从波导传输模式过渡到微带模式,并提供宽带中频信号及直流接地回路;中频输出低通滤波器可有效抑制LO及RF信号,并为其提供等效接地回路。利用肖特基二极管的非线性实现混频,并通过微带匹配电路最终实现宽带低损耗混频效果。混频器采用57.6、62.4、67.2 GHz 3个点频本振,将67~85 GHz的射频信号分段下变频至9.4~17.8 GHz的中频范围内。测试结果表明,在67~85 GHz射频频率范围内,射频输入功率为-15 dBm,本振输入功率为12 dBm时,混频器变频损耗为7.1~10.1 dB,对组合杂散的抑制在36 dBc以上。     

基于倒扣技术的Ka波段环形混频器

给出了一种应用在毫米波前端的单平衡环形混频器。该混频器采用高介电常数的复合材料(R ogersDuro id3010,rε=10.2),以获得较小的芯片面积;电路设计中重点考虑了在较低的本振功率的情况下获得较小的变频损耗,并给出了一种新的混合环的分析方法。当本振在36.5 GH z有9 dBm的功率输入时,混频器有7 dB的变频损耗,双边带噪声系数11.5 dB,本振到中频和射频到中频分别有40.5 dB和31 dB的隔离度。     

Low-noise Ku-band MMIC balanced P-HEMT upconverter

An enhanced design methodology for a low-noise Ku-band monolithic balanced high electron mobility transistor (HEMT) upconverter and its performance are presented in this paper. The mixer topology consists of a common source/common gate HEMT pair that performs the mixing and balun functions. A detailed study has been done to establish the role of the transistor model elements in the performance of the mixer. Based on this study, a new analysis is proposed to optimize the operating point of the mixer in order to get a tradeoff between conversion gain and port isolations. To combine the LO and intermediate-frequency (IF) signals, active circuits were used, as well as a high-pass filter in order to improve the isolations. The circuit size, including the filter and the combiners, is 3 mm². On-wafer measurements show a conversion gain over 2.5 dB, with only 3 dBm of LO power. A LO/RF isolation over 27 dB was measured in the whole LO band. The LO/IF isolation is over 27 dB thanks to the low reverse gain of the combiner HEMT's. A single sideband noise figure of 7.3 dB has been obtained     

Broadband single- and double-balanced resistive HEMT monolithicmixers

A double-balanced (DB) 3-18 GHz and a single-balanced (SB) 2-16 GHz resistive HEMT monolithic mixer have been successfully developed. The DB mixer consists of a AlGaAs/InGaAs HEMT quad, an active LO balun, and two passive baluns for RF and IF. At 16 dBm LO power, this mixer achieves the conversion losses of 7.5-9 dB for 4-13 GHz RF and 7.5-11 dB for 3-18 GHz RF. The SB mixer consists of a pair of AlGaAs/InGaAs HEMT's, an active LO balun, a passive IF balun and a passive RF power divider. At 16 dBm LO power, this mixer achieves the conversion losses of 8-10 dB for 4-15 GHz RF and 8-11 dB for 2-16 GHz RF. The simulated conversion losses of both mixers are very much in agreement with the measured results. Also, the DB mixer achieves a third-order input intercept (IP₃) of +19.5 to +27.5 dBm for a 7-18 GHz RF and 1 GHz IF at a LO drive of 16 dBm while the SB mixer achieves an input IP ₃ of +20 to +28.5 dBm for 2 to 16 GHz RF and 1 GHz IF at a 16 dBm LO power. The bandwidth of the RF and LO frequencies are approximately 6:1 for the DB mixer and 8:1 for the SB mixer. The DB mixer of this work is believed to be the first reported DB resistive HEMT MMIC mixer covering such a broad bandwidth