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。     

High-performance 94-GHz single balanced mixer using 70-nm MHEMTs and surface micromachined technology

We reported 94-GHz, low conversion loss, and high isolation single balanced active gate mixer based on 70-nm gate length InGaAs/InAlAs metamorphic high-electron mobility transistors (MHEMTs). This mixer showed that the conversion loss and isolation characteristics were 2.5/spl sim/3.5 dB and under -29 dB in the range of 92.95/spl sim/94.5 GHz, respectively. The low conversion loss of the mixer is mainly attributed to the high-performance of the MHEMTs exhibiting a maximum drain current density of 607 mA/mm, an extrinsic transconductance of 1015 mS/mm, a current gain cutoff frequency (f/sub t/) of 330 GHz, and a maximum oscillation frequency (f/sub max/) of 425 GHz. High isolation characteristics are due to hybrid ring coupler which adopted dielectric-supported air-gapped microstrip line structure using surface micromachined technology. To our knowledge, these results are the best performance demonstrated from 94 GHz single balanced mixer utilizing GaAs-based HEMTs in terms of conversion loss as well as isolation characteristics.     

140 GHz基于CPWG单平衡基波混频GaAs集成电路

通过在300 μm厚度的GaAs衬底条件下,利用共面波导传输线实现了基波混频集成电路设计。利用半导体分析仪测试I-U和C-U曲线,并成功提取了相应的肖特基二极管模型。结合建立的肖特基二极管模型,代入Lange耦合器、中频结构和匹配网络等实现了140 GHz零中频基波混频片上电路,并加入了地-信号-地(GSG)测试封装。最终仿真结果表明：在固定中频1 GHz的条件下,变频损耗最优为-7 dB,3 dB带宽大于40 GHz。     

Short-slot Hybrid Coupler Using Linear Taper in W-band

-We have designed and fabricated a broadband short-slot hybrid coupler using a two-stage linear taper in W-band. The coupler consists of two metal pieces split at the edge of the narrow wall of the waveguide, which makes it possible to use simple direct machining for fabrication. The electrical performance of the coupler was measured by a Vector Network Analyzer (VNA) at room temperature. The results showed excellent performance as designed: amplitude imbalance between the two output ports of ≤ 1 dB, phase difference between the output ports with respect to 90° < 3°, input return loss < –15 dB, and isolation < –15 dB across the measured frequency range of 85-110 GHz. The short-slot hybrid coupler was used in a balanced Superconductor-Insulator-Superconductor (SIS) mixer at 4 K. The noise performance was almost the same as that of the two single-ended mixers used in the balanced mixer. These results indicate that our short-slot hybrid coupler has great potential for practical applications, such as at millimeter- and submillimeter-waves.     

A Novel 94-GHz MHEMT Resistive Mixer Using a Micromachined Ring Coupler

In this letter, we present a high performance 94-GHz millimeter-wave monolithic integrated circuit resistive mixer using a 70-nm metamorphic high electron mobility transistor (MHEMT) and micromachined ring coupler. A novel three-dimensional structure of a resistive mixer was proposed in this work, and the ring coupler with the surface micromachined dielectric-supported air-gap microstrip line structure was used for high local oscillator/radio frequency (LO–RF) isolation. Also, the LO–RF isolation was optimized through the simulation. The fabricated mixer has excellent LO–RF isolation, greater than 29 dB, in 2-GHz bandwidth of 93–95GHz. The good conversion loss of 8.9dB was measured at 94GHz. To our knowledge, compared to previously reported W-band mixers, the proposed MHEMT-based resistive mixer using a micromachined ring coupler has shown superior LO–RF isolation and conversion loss.     

A V-band planar narrow bandpass filter using a new type integrated waveguide transition

A surface mountable planar narrow bandpass filter is proposed and demonstrated at V-band. The filter is constructed using an integrated waveguide in an alumina substrate employing a novel microstrip line to waveguide transition. The insertion loss per one transition is less than 0.1 dB over 43 to 73 GHz. A fabricated three-pole Chebyshev filter exhibits an insertion loss of 3 dB with a 3.3% bandwidth at a center frequency of 62 GHz and the return loss is better than 15 dB in the passband.     

A 275–425-GHz Tunerless Waveguide Receiver Based on AlN-Barrier SIS Technology

We report on a 275-425-GHz tunerless waveguide receiver with a 3.5-8-GHz IF. As the mixing element, we employ a high-current-density Nb-AlN-Nb superconducting-insulating-superconducting (SIS) tunnel junction. Thanks to the combined use of AlN-barrier SIS technology and a broad bandwidth waveguide to thin-film microstrip transition, we are able to achieve an unprecedented 43% instantaneous bandwidth, limited by the receiver's corrugated feedhorn. The measured double-sideband (DSB) receiver noise temperature, uncorrected for optics loss, ranges from 55 K at 275 GHz, 48 K at 345 GHz, to 72 K at 425 GHz. In this frequency range, the mixer has a DSB conversion loss of 2.3 plusmn1 dB. The intrinsic mixer noise is found to vary between 17-19 K, of which 9 K is attributed to shot noise associated with leakage current below the gap. To improve reliability, the IF circuit and bias injection are entirely planar by design. The instrument was successfully installed at the Caltech Submillimeter Observatory (CSO), Mauna Kea, HI, in October 2006.     

一种基于LTCC 技术的脊基片集成波导（SIW）到微带的过渡结构

介绍了一种基于LTCC 技术的脊基片集成波导（SIW）到微带的过渡结构。将传统脊波导到微带过渡的设计思路,运用于基于LTCC 技术的基片集成波导（SIW）到Rogers5880 基片微带的过渡设计中,实现了LTCC SIW 到Rogers5880 基片微带的宽带过渡。从仿真结果可以看出,在25.2GHz 到40GHz 的频带内,回波损耗S11 小于-15dB, 插入损耗优于-0.2dB。     

A 60-GHz uniplanar MMIC 4/spl times/ subharmonic mixer

A uniplanar GaAs monolithic microwave integrated circuit /spl times/4 subharmonic mixer (SHM) has been fabricated for 60-GHz-band applications using an antiparallel diode pair in finite ground coplanar (FGC) waveguide technology. This mixer is designed to operate at an RF of 58.5-60.5 GHz, an IF of 1.5-2.5 GHz, and an LO frequency of 14-14.5 GHz. FGC transmission-line structures used in the mixer implementation were fully characterized using full-wave electromagnetic simulations and on-wafer measurements. Of several mixer configurations tested, the best results show a maximum conversion loss of 13.2 dB over the specified frequency range with a minimum local-oscillator power of 3 dBm. The minimum upper sideband conversion loss is 11.3 dB at an RF of 58.5 GHz and an IF of 2.5 GHz. This represents excellent performance for a 4/spl times/ SHM operating at 60 GHz.     

一种新型毫米波集成波导微带转换的分析与设计

提出一种新型集成于单层微带基片的毫米波集成波导微带转换 ,由一圆形微带谐振器、微带共面波导探针组成。利用全波分析软件对该转换器进行了分析计算、优化设计。测试了波导微带转换实物 ,结果表明 ,在Ka波段在 1 GHz频带内 ,该波导微带转换具有较低的插入损耗 ( <0 .4d B)和反射损耗 ( <-1 4d B)。可满足相关毫米波微带集成电路系统的应用要求。     

W 波段单平衡混频器的设计

本文设计并制作了一种微带形式W 波段单平衡混频器。该混频器采用微带环形电桥结构,射频和本振信号分别从环形电桥的隔离端口由标准波导BJ-900 输入,经对脊鳍线微带波导过渡输入到微带电路,中频信号通过跳线方式连接并通过一段高阻抗线引出到输出口。该电路使用两只DMK2790 肖特基二极管制作在介电常数为2.2,厚度为0.127mm 的RT/Duriod5880 基片上,在固定本振94.5GHz,射频90GHz 到98GHz 范围内,变频损耗小于14.5dB。     

A Novel 94-GHz MHMET-Based Diode Mixer Using a 3–dB Tandem Coupler

We report a high-performance 94-GHz monolithic millimeter-wave integrated-circuit diode mixer using metamorphic high-electron mobility transistor (MHEMT) diodes and a coplanar waveguide tandem coupler. A novel single-balanced structure of diode mixer is proposed in this paper, where a 3-dB tandem coupler with two sections of parallel-coupled line and air-bridge crossover structures are used for wide frequency operation. The fabricated mixer exhibits excellent local oscillator–radio-frequency (LO–RF) isolation, greater than 30 dB, in the 5-GHz bandwidth of 91–96 GHz. A good conversion loss of 7.4 dB is measured at 94 GHz. The proposed MHEMT-based diode mixer shows superior LO–RF isolation and conversion loss to those of the W-band mixers reported to date.      

A D‐Band Balanced Subharmonically‐Pumped Resistive Mixer Based on 100‐nm mHEMT Technology

A D‐band subharmonically‐pumped resistive mixer has been designed, processed, and experimentally tested. The circuit is based on a 180° power divider structure consisting of a Lange coupler followed by a λ/4 transmission line (at local oscillator (LO) frequency). This monolithic microwave integrated circuit (MMIC) has been realized in coplanar waveguide technology by using an InAlAs/InGaAs‐based metamorphic high electron mobility transistor process with 100‐nm gate length. The MMIC achieves a measured conversion loss between 12.5 dB and 16 dB in the radio frequency bandwidth from 120 GHz to 150 GHz with 4‐dBm LO drive and an intermediate frequency of 100 MHz. The input 1‐dB compression point and IIP3 were simulated to be 2 dBm and 13 dBm, respectively.     

基于LGA工艺的D波段微带线－波导过渡结构

设计了一个工作于D波段的微带转波导结构。过渡结构由2部分组成,分别为微带－带状线过渡结构和带状线－波导过渡结构。相比传统的微带至波导结构,该结构无需额外的金属波导短路结构,减少了加工流程,直接和标准波导相连即可。仿真结果表明,在122~140 GHz范围内,反射系数小于-10 dB,最小插入损耗为1.85 dB。该过渡结构基于栅格阵列(LGA)封装工艺,能够直接与其他的芯片和无源器件进行集成和封装,对射频微系统的集成具有重要意义。     

High-performance quasi-optical GaAs monolithic mixer at 110 GHz

A novel GaAs monolithic integrated circuit mixer has been fabricated which is impedance matched to fundamental waveguide. It consists of a slot coupler, coplanar transmission line, surface-oriented Schottky-barrier diode, and RF bypass capacitor monolithically integrated on the GaAs surface. At 110 GHz, a monolithic mixer module mounted in the end of a waveguide horn has an uncooled double-sideband (DSB) mixer noise temperature of 339 K and conversion loss of 3.8 dB.     

超宽带谐波混频器的设计

叙述了一种超宽带谐波混频器的原理、设计以及测试结果。该混频器主要由微带线巴伦、倍频器、单平衡混频器三部分组成。按中心频率为4.5 GHz设计出微带线巴伦结构,平衡端口输出相位差180°,具有尺寸小、损耗低、幅度相位一致性好等优点;采用AEROFLEX公司的MSPD2018型相位检波器作为混频器,该混频器采用阶跃恢复二极管倍频器与单平衡混频器并联结构,先倍频n次谐波后再与信号进行混频;传输线为四分之一波长线以提高端口间隔离度;利用微波电路仿真软件ADS对混频器进行基波和谐波分析。测试结果表明,在3～25 GHz的频率范围内,本振至中频的隔离度优于66 dB,其变频损耗的实测结果满足设计要求,在现有的宽带混频器中具有较好性能。     

Coplanar-waveguide/microstrip probe coupler and applications to antennas

A method to couple microwave power from a coplanar waveguide to a microstrip line on opposite sides of a ground plane is demonstrated. The measured insertion loss and return loss are about 1 dB and 10 dB, respectively, across the frequency range of 0.045-6.5 GHz. To demonstrate potential applications of the coupler as a feeding network for a microstrip patch array measured radiation patterns for two rectangular patch antennas with a direct coplanar-waveguide/microstrip feed and with a proximity coupled coplanar-waveguide/microstrip feed are presented.<>     

0.1 THz鳍线单平衡式基波混频电路研究

研究了一种基于石英基片的0.1 THz频段的鳍线单平衡混频电路,混频电路的射频和本振信号分别从WR10标准波导端口通过波导单面鳍线微带过渡和波导微带探针过渡输入,中频信号通过本振中频双工器输出。这是一种新型的混频电路形式,与传统的W波段混频器相比,混频电路可以省略一个复杂的W波段滤波器,具有电路设计简单、安装方便的特点。该电路使用两只肖特基二极管通过倒装焊工艺粘结在厚度为75 m的石英基片上,石英基片相对传统基板,可以极大提高电路加工精度。在固定50 MHz中频信号时,射频90~110 GHz范围内,0.1 THz混频器单边带变频损耗小于9 dB。     

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.     

一种X 波段磁场耦合式波导-微带转换结构

波导-微带转换器是微波集成电路和天馈线系统中的重要器件。结合具体应用,设计了一款新型、宽带磁耦合式波导-微带转换器。和传统结构相比,本设计用双层的贴片结构代替金属块状阶梯脊,通过在贴片上加载金属过孔来展宽转换的带宽;将阶梯状金属贴片和微带探针一体化设计,从而避免了焊接带来的损耗和结构不稳定,并且减小了加工难度,降低了重量和成本。测试结果表明,波导-微带转换器的两个端口在8.85～11.52GHz 的频带内回波损耗小于-15 dB,插入损耗约为0.8dB,均满足应用需求。