W-band broadband integrated circuit mixers

Broadband integrated circuit mixers using a crossbar stripline configuration and a finline configuration have been developed. For the crossbar stripline balanced mixer, less than 7.5 dB conversion loss for 15 GHz instantaneous IF bandwidth has been achieved with the LO at 75 GHz and the RF swept from 76 to 91 GHz. For the finline balanced mixer, a conversion loss of 9 to 12 dB over a 19 GHz instantaneous IF bandwidth has been achieved as the RF is swept from 91 to 110GHz.     

W-band micromachined circuit combining networks

In circuit-combining networks, low-loss interconnecting transmission lines are pivotal in reducing excess loss. Micromachined finite ground coplanar waveguides are used in this study as low-loss interconnects showing significant improvements in line loss while maintaining 50-Ω characteristic impedance. Wilkinson power dividers, reactive tee junctions, and right-angle bends are combined with micromachined interconnects in 1:2, 1:4, and 1:8 power-dividing networks and show measured loss reduction of 0.3-1.0 dB depending on circuit type and size from 85 to 95 GHz     

W-band direct detection circuit performance with Sb-heterostructure diodes

W-band direct detection circuits have been designed and fabricated for use in a passive millimeter wave camera. The circuits are based on the recently developed Sb-heterostructure diode. We measure record voltage responsivities in test circuits, up to 8,000 mV/mW from 75 to 93 GHz, with input power from -50 to -30 dBm. Performance was similar in an actual camera frequency processor board with 128 tuned channels. 72% of detectors showed responsivity at or above 6,000 mV/mW and 3% of channels were above 10,000 mV/mW. Since tens of thousands of Sb-heterostructure diodes can be reproducibly and inexpensively fabricated, this demonstrates for the first time the feasibility of large-scale detector arrays utilizing zero bias direct detection circuitry.     

On-wafer noise-parameter measurements at W-band

A wide-band on-wafer noise-parameter measurement setup has been developed for W-band. The system is based on a cold-source method and uses a simple manual impedance tuner. In addition to noise parameters, S-parameters can be measured with the same setup. Using the developed system, noise parameters of an InP high electron-mobility transistor have been measured and results are shown in the 79-94-GHz frequency band. This is the first comprehensive report of noise-parameter measurements made on active devices at W-band.     

W波段连续波带状注扩展互作用速调管高频电路的设计

针对W波段速调管难以实现连续波高功率的问题,设计了一个工作在TM₃₁-2π模式的W波段连续波带状注扩展相互作用速调管（EIK）高频电路,该电路采用电压20 kV、电流0.65 A,2.5 mm×0.3 mm的带状电子注,高频系统采用五个哑铃型的五间隙谐振腔,输出系统采用对称输出波导。通过理论设计和高频结构参数优化,三维PIC仿真结果显示：在输入功率0.2 W的条件下,能够获得超过1200 W的输出功率,效率和增益分别为9.35%和37.8 dB。在高频参数敏感性和误差稳定性方面,对TM₃₁模式和TM₁₁模式进行了详细的对比分析。     

Quasi-optical resonator for power combining at W-band

Laser resonator technique is employed for obtaining efficient, spectrally pure and narrow band output from a CW GUNN source operating around 94GHz. The same resonator configuration, used for two similar GUNN sources results in combined power output at W-band.     

Performance of silicon micromachined waveguide at W-band

Fabrication and measurement of low-loss micromachined waveguides developed in (001) silicon through wet anisotropic etching is detailed. Such waveguides are candidates for use in submillimetre-wave systems owing to their compatibility with both efficient micromachined horn antenna elements and planar-based circuitry     

W波段双极化单脉冲天线设计

为了探测目标的极化特性,研制了工作在W波段的双极化单脉冲卡塞格伦天线.天线由主反射面、副反射面、馈源喇叭、正交模耦合器及和差器组成.天线主反射面口径为137 mm,馈源为五喇叭形式,正交模耦合器采用渐变波导匹配方案,和差器通过平面型定向耦合结构实现.通过将馈源喇叭、正交模耦合器及和差器集成设计,减小了连接损耗,压缩了天线纵向尺寸.测试结果表明,天线驻波带宽约3. 7 GHz,极化隔离度优于35 dB,和波束增益大于37. 9 dBi,副瓣电平优于-15 dB,差波束零深优于-25 dB.天线在W波段实现了较好地双极化单脉冲性能.     

Full-Wave Analysis of Monopulse Dielectric Lens Antennas at W-band

Lens antenna is a good substitute for the Cassegrain antenna at millimeter-wave frequencies, especially at W-band. On one hand, the antenna design, which is bulky and heavy at low frequencies, becomes compact and light-weighted at W-band. On the other hand, without the blockage caused by the sub-reflector and the feed horns which are unavoidable in a Cassegrain antenna, the lens antennas show better radiation characteristics. In this paper, several lens antennas fed by metal horns are analyzed using a full-wave method-finite element method based on the weak form of the Helmholtz equation (WF-FEM). Numerical results show that the lens antennas presented have low side lobe level (SLL), and good sum and difference performances.     

基于新型多间隙谐振腔的W波段高次模式扩展互作用速调管设计（英文）

提出了一种工作在TM310模式下的用于高次模式速调管的新型谐振腔。通过对侧腔电场的离散化,可以有效地增强中间腔和侧腔的电场。当两腔均工作在TM310模式时,新型谐振腔的特性阻抗均高于传统的哑铃型腔。对两种腔体进行了尺寸敏感性分析。在此基础上,设计了一个W频段的射频电路。当向射频电路注入45 mW的输入功率时,获得了52.4 dB的高增益和7.8 kW的峰值输出功率。互作用电路由25 kV、2 A的圆形电子注驱动。该互作用电路的电子效率和3-dB带宽分别为15.6%和120 MHz。     

Some aspects of bias current tuning of W-band IMPATT diodes mounted in a reduced-height waveguide circuit

The bias current tuning of W-band IMPATTs in reduced-height waveguide circuits have been discussed in details. The measured tuning response can be increasing, decreasing or practically insensitive with bias current depending on the device and circuit parameters. The observed results are explaine with a simple device-circuit interaction model.     

Self-oscillating mixing in a QW double barrier diode at W-band

We report the presence of self-oscillating mixing in an asymmetric quantum well double barrier diode at 86GHz. We have demonstrated that the QW device can be injection-locked to the RF signal, and that the intermediate frequency (IF) can exhibit both upper and sub harmonics. Conversion gain was measured and found to be typically ?30 to ?40dB, with a best measurement of ?18.79dB. Under certain conditions, the IF could show wideband chaotic-like oscillations extending to 1500Mhz.     

Micromachined W-band filters

Results are presented for high performance planar W-band filters based on silicon micromachining techniques common in microsensor fabrication. Two types of micromachined planar transmission lines are studied: microshield line and shielded membrane microstrip (SMM) line. In both of these structures, the conducting lines are suspended on thin dielectric membranes. These transmission lines are essentially “floating” in air, possess negligible levels of dielectric loss, and do not suffer from the parasitic effects of radiation and dispersion. A 90 GHz low pass filter and several 95 GHz bandpass filters are tested and display excellent performance which cannot be achieved with traditional substrate supported circuits in CPW or microstrip configurations. A full-wave finite-difference time-domain (FDTD) technique verifies the measured performance of the W-band circuits and provides a basis for comparison between the performances of membrane supported circuits and equivalent substrate supported circuits     

Impedance and complex propagation constant measurements at W-band on planar circuits

The voltage standing wave on a coplanar waveguide (CPW) is measured at W-band (75–110 GHz) using an array of bismuth microbolometers placed over the CPW. From this information, the impedance at the end of the line can be determined in addition to the complex propagation constant of the CPW. This measurement technique should also be applicable for other planar transmission lines and be extendable above 110 GHz. This work represents the highest frequency, direct measurement of a VSW on a CPW made to date.     

基于相位再同步技术的W波段高效率分布作用振荡器的研究

对基于12个周期的交错双排矩形波导慢波结构(staggered double rectangular waveguide slow wave structure,简记为SDRWSWS)的单谐振腔94.5GHz分布作用振荡器(extended interaction oscillator,EIO)进行了计算机模拟,给出了通过计算机模拟确定谐振腔结构参数及电子注参数的方法和步骤。提出了"相位再同步"的高效率方法,将谐振腔中从电子注输入端数起的第5~6个周期的慢波结构的周期降低到原来的90%左右,改变了谐振腔中轴向电场强度的分布,使轴向电场强度在远离输出口一端相对降低,而在靠近输出口一端相对升高,有助于电子注的调制随着电子注的行进而加强;同时,使在靠近输出口一端的轴向电场强度的相位增大了51.6°,从而与电子注的空间电荷波的相位保持同步并从电子注提取更多能量。计算机模拟结果证实,采用该技术的分布作用振荡器的功率和电子效率都得到显著提高,改善最大的数值是原来的2倍以上。     

Noise and mixing properties of high-Tc Josephson junctions at W-band frequencies

We report on the noise and Josephson mixing properties of high-T_c superconductor (HTS) Josephson junctions. Direct radiation measurements and heterodyne mixing experiments in the frequency range 45–141 GHz have been performed by using YBa₂Cu₃O_7−x (YBCO) step-edge junctions (SEJ) on LaAlO₃ and MgO and bicrystal junctions (BCJ) on MgO substrates. Junctions with current voltage characteristics (CVC) close to predictions of the resistivity shunted junction (RSJ) model were mounted into a high sensitive radiometer system. From linewidth measurements we calculated an effective noise temperature of our junctions. In heterodyne mixing experiments we obtained conversion efficiencies around −14 dB in the 11 GHz intermediate frequency (IF) band under the radiation of two monochromatic signals. In the fundamental mixing regime we observed response at IF at working temperatures up to 72 K. The measured receiver and mixer noise temperature of the Josephson mixer at 94 GHz local oscillator (LO) frequency, an IF of 1.4 GHz and at a working temperature of 10 K was 4700 and 3400 K, respectively.     

Optical interaction in active analog circuit elements

This publication introduces (spectral) photon emission (PEM) and electro-optical frequency mapping (EOFM/LVI) measurements to analog circuit elements (simple, cascode and low-voltage current mirrors). Different operating conditions of the devices are probed and the voltage dependence of the signals is analyzed. Results partly show close similarities to optical probing of digital IC's, but also differences in voltage dependence and signal levels due to more complicated voltage and signal distributions along the devices.     

W波段低电压宽带过模矩形同轴曲折波导行波管的研究

提出了一种具有高频率、宽频带和低电压特点的矩形同轴曲折波导慢波结构,所提出的矩形同轴曲折波导工作于过模状态,工作频率较高,同时具有不错的传输特性。设计了一种宽带的双脊加载的波导-同轴转换器,其带宽可以覆盖矩形同轴曲折波导行波管的整个工作频带。所设计的矩形同轴曲折波导行波管工作电压和电流分别为3230 V和150 mA,慢波结构长度为32 mm,PIC仿真结果表明,在76～110 GHz频率范围内,其输出功率超过13.7 W,在108GHz频点,输出功率达到最大值,约为27.4 W,对应的射频效率为 5.65%。     

三毫米FMCW组件及高线性度实时校正技术

根据ＦＭＣＷ雷达的工作原理，本文采用新技术和小型化３ｍｍ元部件，设计了先进的３ｍｍ前端电路，大大减小了组件体积，并采用了模拟一数字混合电路，由高速单片计算机完成了对３ｍｍＶＣＯ的调频线性度闭环实时校正，组件工作频率９４．８ＧＨｚ调频带宽２８０ＭＨｚ，发射功率大于５ｍＷ，调频线性度优于０．２‰。