一种新颖的鳍线单刀双掷开关

介绍一种只需要一个偏置控制端口,采用正负脉冲驱动的T形结鳍线单刀双掷开关的设计方法。在电路中采取改进措施,提高了隔离度、降低了插入损耗,测量结果表明,开关在Ka频段内,插入损耗≤1.5dB,隔离度≥30dB;在W频段内,插入损耗≤2dB,隔离度≥25dB。     

W波段单刀双掷开关

实现了一种采用微波开关（PIN）二极管设计的低插损、高隔离度的 W波段单刀双掷开关（SPDT）。电路采用了改进的 Y 型结和梳状线高通滤波器形式的鳍线结构,有效提高了端口隔离度,降低了插入损耗。仿真结果显示,导通端口在88 GHz～99 GHz内的插入损耗小于0.7 dB,断开端口隔离度大于58 dB。测试结果显示,在频段90 GHz～95 GHz内,输入端口与输出端口1之间的插入损耗低于3.7 dB、隔离度高于33 dB;输入端口与输出端口2之间的隔离度高于33 dB、插入损耗低于3.8 dB。     

高隔离度X波段RF MEMS电容式并联开关

研究了一种新型的、应用于X波段的高隔离度RF MEMS电容式并联开关结构。相比于普通的并联结构,该开关通过共面波导(CPW)传输线与地平面之间的衬底刻槽结构将隔离度提高了7dB,关态时在13.5GHz谐振频率处的隔离度为-54.6dB,执行电压为26V。弹簧梁结构开关的执行电压下降为14V,在11GHz处其隔离度为-42.8dB。通过两个并联开关级联与开关间的高阻传输线构成的π型调谐开关电路,在11.5GHz处的隔离度为-81.6dB。     

高隔离度宽频段组合式RF-MEMS开关的设计

接触式与电容耦合式两类RF MEMS开关各自在一定的频段内,都具有较高的隔离度,但仍然很难满足微波控制系统中对高隔离度的要求.为了获得全波段高隔离度RF MEMS开关,单元开关很难达到要求,在此目标要求下,提出了组合式RF MEMS开关的设计,分别利用HFSS软件对各单元进行结构参数优化,再将两者集成在一起,得到的组合式RF MEMS开关,这种组合式开关在0～20 GHz时隔离度都高于-60 dB,在(≤5 GHz),隔离度高于-70 dB,这是一般单元开关及其他半导体固态开关所无法企及的,而且,在DC～20 GHz范围内,开关的插入损耗小于-0.20 dB,而且并没因隔离度的提高,牺牲了插入损耗.     

Q波段双通道幅度控制多功能芯片

设计了一款Q波段的双通道多功能单片电路,其内部集成了威尔金森功分器、六位0.5 dB步进数控衰减器和单刀双掷开关。在设计过程中,开关单元电路采用三级并联结构,有效降低电路插入损耗,提高隔离度;数控衰减器单元采用多节并联T型结构,改善高频段插入损耗和衰减精确度指标。通过以上设计方法,该单片电路在40~50 GHz插入损耗为10 dB,隔离度为26 dB;能够实现幅度控制步进0.5 dB,最大衰减量31.5 dB。     

一种高线性度非对称单刀双掷开关的设计

介绍了一种用于射频收发系统的16 GHz、低损耗、高隔离度、高线性度的非对称型单刀双掷开关。针对串联和并联晶体管尺寸对插入损耗及隔离度的影响、对称型和非对称型两种结构各自的特点,以及选择非对称结构的原因进行了分析。采用90 nm CMOS工艺实现,设计中采用深N阱MOS管,并在必要的节点加入交流悬浮偏置,提高开关整体性能。测试表明,Rx模式下,插损为0.77 dB,隔离度为22.9 dB,输入1 dB压缩点为9 dBm;Tx模式下,插损为2.14 dB,隔离度为20.2 dB,输入1 dB压缩点大于15 dBm。     

基于45 nm SOI工艺的超宽带毫米波单刀双掷开关的设计北大核心CSCD

提出了基于GlobalFoundries 45nm SOI工艺的布局紧凑的宽带毫米波单刀双掷开关。设计包括了采用串并结构的全频段单刀双掷开关以及采用两级晶体管并联的Ka波段通带单刀双掷开关。设计中采用共面波导串联短截线,实现小尺寸的电感。此外,利用负体偏置技术提高了开关在毫米波波段的性能。设计的单刀双掷开关芯片核心面积为0.35mm×0.16mm。测量结果显示全频段单刀双掷开关在DC^94GHz的插入损耗小于4dB,隔离度大于24dB,而Ka波段通带单刀双掷开关在25~45GHz的插入损耗为2.5~3.2dB,隔离度大于19dB。     

1~26.5GHz GaAs PIN单刀单掷开关单片

采用GaAs PIN二极管,完成1~26.5 GHz的单刀单掷开关单片的设计、制作。SPST开关单片带内插损小于0.5 dB,驻波优于1.1,隔离度大于27 dB,在10~26.5 GHz,隔离度大于37 dB。开关单片采用MOCVD生长的GaAs纵向PIN二极管材料结构,76 mm GaAs圆片工艺加工制作。     

带有直流偏置的毫米波单刀双掷开关仿真与设计

采用阶跃阻抗传输线和扇形微带短截线,实现了单刀双掷开关的直流偏置,使直流支路与毫米波支路之间的隔离度大于30dB,带宽超过25%,在中心频率30GHz附近回波损耗大于40dB。采用这种直流偏置电路和PIN梁式引线二极管,基于LTCC工艺对单刀双掷开关串联结构进行仿真。设计结果表明在28.5～31.5GHz频率范围内,串联开关的插入损耗小于1.5dB,回波损耗大于15dB,隔离度大于20dB。     

基于Q-MMIC技术的W波段低成本PIN管开关

采用低成本方法设计了一款W波段单刀单掷开关。通过在单独加工的石英基片无源电路上安装倒装PIN管,获得了一款W波段准毫米波单片（Q-MMIC）开关。为了获得低损耗、高隔离度性能,开关设计中采用了3-D PIN管模型和电路补偿结构。测试结果表明开关在88GHz时插入损耗最小,最小值为0.5dB;在80-101 GHz频率范围内,开关导通时的插入损耗小于2 dB;在84-104 GHz频率范围内,开关隔离度大于30 dB。整个开关电路尺寸为1.5 mm× 3.0 mm。     

Design of Dual‐Band MIMO Antenna with High Isolation for WLAN Mobile Terminal

In this paper, we propose a dual‐band multiple‐input multiple‐output (MIMO) antenna with high isolation for WLAN applications (2.45 GHz and 5.2 GHz). The proposed antenna is composed of a mobile communication terminal board, eight radiators, a coaxial feed line, and slots for isolation. The measured ?10 dB impedance bandwidths are 10.1% (2.35 GHz to 2.6 GHz) and 3.85% (5.1 GHz to 5.3 GHz) at each frequency band. The proposed four‐element MIMO antenna has an isolation of better than 35 dB at 2.45 GHz and 45 dB at 5.2 GHz between each element. The antenna gain is 3.2 dBi at 2.45 GHz and 4.2 dBi at 5.2 GHz.     

Quasiplanar 3 dB hybrid for millimetre-wave integrated circuits

A quasiplanar 3 dB hybrid suitable for integration in millimetre-wave fin-line circuits is presented. The performance of the device is characterised by 0.5 dB insertion loss, less than 0.5 dB imbalance and 20?25 dB isolation over the entire Ka-band (26.5?40 GHz).     

A 90–96 GHz CMOS down-conversion mixer with high conversion gain and excellent LO–RF isolation

A 90–96 GHz down-conversion mixer for 94 GHz image radar sensors using standard 90 nm CMOS technology is reported. RF negative resistance compensation technique, i.e. NMOS LC-oscillator-based RF transconductance (GM) stage load, is used to increase the output impedance and suppress the feedback capacitance C_gd of RF GM stage. Hence, conversion gain (CG), noise figure (NF) and LO–RF isolation of the mixer can be enhanced. The mixer consumes 15 mW and achieves excellent RF-port input reflection coefficient of ?10 to ?36.4 dB for frequencies of 85–105 GHz. The corresponding -10 dB input matching bandwidth is 20 GHz. In addition, for frequencies of 90–96 GHz, the mixer achieves CG of 6.3–9 dB (the corresponding 3-dB CG bandwidth is greater than 6 GHz) and LO–RF isolation of 40–45.1 dB, one of the best CG and LO–RF isolation results ever reported for a down-conversion mixer with operation frequency around 94 GHz. Furthermore, the mixer achieves an excellent input third-order intercept point of 1 dBm at 94 GHz. These results demonstrate the proposed down-conversion mixer architecture is very promising for 94 GHz image radar sensors.     

Design and implementation of a 94 GHz CMOS down-conversion mixer with integrated miniature planar baluns for image radar sensors

A 94 GHz down-conversion mixer for image radar sensors using standard 90 nm CMOS technology is reported. The down-conversion mixer comprises a double-balanced Gilbert cell with peaking inductors between RF transconductance stage and LO switching transistors for conversion gain (CG) enhancement and noise figure suppression, a miniature planar balun for converting the single RF input signals to differential signals, another miniature planar balun for converting the single LO input signals to differential signals, and an IF amplifier. The mixer consumes 22.5 mW and achieves excellent RF-port input reflection coefficient of ?10 to ?35.9 dB for frequencies of 87.6–104.4 GHz, and LO-port input reflection coefficient of ?10 to ?31.9 dB for frequencies of 88.2–110 GHz. In addition, the mixer achieves CG of 4.9–7.9 dB for frequencies of 81.8–105.8 GHz (the corresponding 3-dB CG bandwidth is 24 GHz) and LO–RF isolation of 37.7–47.5 dB for frequencies of 80–110 GHz, one of the best CG and LO–RF isolation results ever reported for a down-conversion mixer with operation frequency around 94 GHz. Furthermore, the mixer achieves an excellent input third-order intercept point of ?3 dBm at 94 GHz. These results demonstrate the proposed down-conversion mixer architecture is promising for 94 GHz image radar sensors.     

A low-voltage ultra-wideband down-conversion mixer with improved power conversion gain

This article presents a wideband mixer using a TSMC 0.18?µm complementary metal-oxide semiconductor technology process for ultra-wideband (UWB) system applications. The measured 3-dB radio frequency (RF) bandwidth is from 3 to 8.4?GHz with an intermediate frequency of 10?MHz. The measurement results of the proposed mixer achieve 8.1?dB average power conversion gain ?5?dBm input third-order intercept point (IIP3) at 7.4?GHz and 12.4–13.3?dB double side band noise figure. The total dc power consumption of this mixer including output buffers is 3.18?mW from a 1?V supply voltage. The output current buffer consumption is about 2.26?mW with an excellent local oscillator-RF isolation of up to 40?dB at 5?GHz. The article presents a mixer topology that is greatly suitable for low-power operation in UWB system applications.     

Travelling-wave amplifier using thin epitaxial GaAs layer

A solid-state travelling-wave amplifier has been fabricated in 1 ?m n type epitaxial GaAs on a semi-insulating substrate. It shows a net gain around 5, 7.5, 9 and 11.5 GHz, with a maximum value of 13 dB at 11.5 GHz. Other features include c.w. operation, 20?30 dB isolation, and voltage-controlled phase shifting with constant gain.     

Gigahertz-band analogue switch using bipolar super self-aligned process technology

A novel bipolar analogue switch has been developed using super self-aligned process technology (SST). The switch with three emitter-coupled pairs achieved high net isolation of 40 dB and low third-order intermodulation of less than ?40 dB below the input level of ?7 dBm at 1 GHz.     

W-Band CMOS down-conversion mixer using micromixer-based gain-enhanced technique

We demonstrate a W-band down-conversion micromixer for imaging and gesture recognition transceiver. Micromixer-based gain-boosted technique, i.e. inductive-peaking gain-boosted single-to- differential transconductance (g_m) stage, is adopted to increase the output impedance and restrain the feedback capacitance C_gd of the g_m stage. This leads to the conversion gain (CG), noise figure (NF) and LO-to-RF leakage of the micromixer being significantly improved. The micromixer dissipates 7.2 mW and attains marvellous RF-port return loss of ?12.7~ ?14.7 dB for 85 ~ 110 GHz. That is, the ?10 dB matching bandwidth is wider than 25 GHz. Moreover, for 90 ~ 96 GHz, the micromixer attains CG of 10.5 ~ 12 dB and LO-to-RF isolation of 40.2 ~ 46.2 dB, one of the highest values ever demonstrated for a W-band mixer/micromixer. The 3 dB CG bandwidth is 22 GHz (83 ~ 105 GHz), and the input third-order intercept point (IIP3) is 1 dBm. These results indicate the micromixer is appropriate for W-band imaging and gesture recognition transceivers.     

170 GHz和340 GHz CSMRs滤波器选频网络研究

为了实现倍频器多谐波输出,满足系统多频率需求,同时减少成本,增加系统集成度,引入了改进紧凑型悬置微带谐振单元（Compact Suspended Microstrip Resonators（CSMRs））滤波器,主要研究并实现了170 GHz和340 GHz双频段分别输出。仿真中分别设计170 GHz和340 GHz探针,引入CSMRs低通滤波器增加170 GHz对高频段的隔离,减小波导高度,提高WR.2.8波导截止频率,增加对300 GHz以下频段抑制,为了测试其输出特性和网络损耗,设计170~340 GHz背靠背模块。仿真结果为低通CSMRs滤波器满足在20~180 GHz通带内反射系数小于-18 dB,在266~520 GHz阻带内抑制度大于20 dB,背靠背结构仿真170 GHz与340 GHz频段反射系数均小于-15 dB,端口隔离大于30 dB,表现出良好的选频特性。测试结果表明:在170 GHz端口通带为150~185 GHz,反射系数小于-10 dB,损耗大于1.2 dB;在340 GHz端口,通带为306~355 GHz,反射系数小于-10 dB,损耗2 dB,两端口隔离度大于10 dB,最好60 dB。     

C波段单片有源环行器基本单元的研究

本文分析和研究了微波有源环行器所用的基本单元电路——放大器和定向耦合器.利用微波CAD欢件完成了放大器、定向耦合器和有源环行器的设计.模拟分析得出:在3.8～4.2GHz频率范围内,单片放大器的正向增益是6dB.反向隔离度为22dB:单片定向耦合器的正向插入损耗是4dB,反向隔离度为18dB.该有源环行器的隔离度是19dB,正向插损是5dB.实验结果为:放大器在3.5～4.0GHz频率范围内,正向增益是4.5dB,反向隔离度是23dB;定向耦合器在3.2～3.8GHz频率范围内,正向插入损耗是8dB,反向隔离度为23dB.