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.     

Optimized design of quasi-optical source-array of solid state source power combiner at frequency 100 GHz

It is determined for the structure of the source-array located in inner surface of input quasi-optical resonator operating at frequency 100GHz using Type WT5731 GaAs Gunn diodes made in P.R. China (fundamental frequency 50 GHz). An adaptable phase coupling has been achieved and RF output power exceeded the sum of the individual diode outputs by from three to seven times.     

A dual-polarized quasi-optical SIS mixer at 550 GHz

In this paper, we describe the design, fabrication, and the performance of a low-noise dual-polarized quasi-optical superconductor-insulator-superconductor (SIS) mixer at 550 GHz. The mixer utilizes a novel cross-slot antenna on a hyperhemispherical substrate lens, two junction tuning circuits, niobium trilayer junctions, and an IF circuit containing a lumped element 180° hybrid. The antenna consists of an orthogonal pair of twin-slot antennas, and has four feed points, two for each polarization. Each feed point is coupled to a two-junction SIS mixer. The 180° IF hybrid is implemented using a lumped element/microstrip circuit located inside the mixer block. Fourier transform spectrometer measurements of the mixer frequency response show good agreement with computer simulations. The measured co-polarized and cross-polarized patterns for both polarizations also agree with the theoretical predictions. The noise performance of the dual-polarized mixer is excellent giving uncorrected receiver noise temperature of better than 115 K (double sideband) at 528 GHz for both the polarizations     

150 GHz大功率二倍频器

基于六阳极结反向串联型砷化镓平面肖特基容性二极管,采用平衡式二倍频器结构,成功研制出一种大功率150 GHz二倍频器。使用三维电磁场与非线性谐波平衡联合仿真方法,提高了仿真结果和实际的吻合度,并根据设计结果完成倍频器的加工、装配和测试。倍频器在输出频率为146~158 GHz下的倍频效率达到7%以上;在输出频率为154 GHz时,倍频效率达到12%,输出功率达到71 mW。     

三维射线跟踪预测模型在5.8GHz的实验验证

验证了一种用于无线信道特性预测的三维射线跟踪模型的计算方法.在 5.8GHz分别用不同的天线对视线和非视线两大类情形进行了仿真和测量,结果表明测量值和仿真值一致.     

Application of 150GHz quasi-optical EPR and endor systems to examination of materials for polarized nuclear targets

Some possibilities of mm and submm magnetic resonance spectrometers using a two-mirror open resonator as the sensor is demonstrated. A comparative analysis of sensitivity has been performed for spectrometer, with cavity and open resonators. Absorption spectra of the HMBA Cr^V complex in propylene glycol and ethylene glycol were investigated at 4.2 K.     

170 GHz回旋管准光模式变换器的设计

针对170 GHz回旋管研究,设计了一种高效Denisov准光模式变换器,该回旋管工作在模式。模式变换器由微扰结构的辐射器和镜面系统组成。基于耦合模理论和矢量绕射理论,研究了两级微扰辐射器,优化设计了镜面系统。仿真结果显示,模式转换为高斯光束,其输出功率转换效率为93.7%。     

一种8 mm频段封闭腔全息准光功率合成网络的设计

基于周期相位栅格的塔尔博特效应,提出了一种新型的毫米波频段18合1封闭腔全息准光高效功率合成网络。采用了相邻半周期相差仔的特殊周期相位栅格,置于垂直于栅格的零场区域的金属壁封闭了合成网络,解决了辐射损耗和电磁泄漏问题。基于光学标量衍射理论算法仿真的衍射图样与目标场对比得到的适应度函数,以基因算法优化得到相位栅格,并以变宽波导阵透镜物理实现。在37.5 GHz,功率合成网络实物测试的效率为81%,与电磁仿真的89%基本相符。准光功率合成网络可由一维扩展至二维,合成效率与阵元数、阵元间距无关,可实现毫米波及THz频段的大规模数量器件高效功率合成。     

Monolithic quasi-optical frequency tripler array with 5-W outputpower at 99 GHz

Two devices, the multi-quantum-barrier varactor (MQBV) and the Schottky-quantum-barrier varactor (SQBV), have been developed and applied in quasi-optical arrays for millimeter-wave harmonic generation. Monolithic arrays utilizing these devices have been successfully fabricated with nearly 100% yield. An output power of 5 W (1.25 W) at 99 GHz has been achieved with an SQBV (MQBV) tripler array, in excellent agreement with large-signal simulation predictions after correcting for diffraction losses in the matching system. These results represent the state of the art in solid-state millimeter-wave sources     

A 20 mW, 150 GHz InP HEMT MMIC power amplifier module

This paper describes a power amplifier (PA) module containing an InP high electron mobility transistor (HEMT) monolithic millimeter-wave integrated circuit (MMIC) amplifier chip, designed, and packaged at the Jet Propulsion Laboratory, and fabricated at HRL Laboratories. The module features 20 mW of output power at 150 GHz, with more than 10 mW available in the 148-160 GHz frequency range.     

150 GHz低损耗Lange耦合器的设计

采用0.13 μm SiGe BiCMOS工艺,设计了一个中心频率为150 GHz的低损耗Lange耦合器。使用λ/4波长线为耦合线,4个端口采用50 Ω匹配线以降低回波损耗;为得到更好的插入损耗,在耦合器对应的地面打孔形成地面隔离带,有效降低了插入损耗。仿真结果表明,耦合器在中心频率150 GHz处,带宽20 GHz范围内的耦合度为3.5 dB,插入损耗小于0.6 dB,回波损耗与隔离度均小于-20 dB,相位误差在2°之内,耦合输出与直通输出幅值误差在0.1 dB以下。该Lange耦合器在D波段功率放大器、混频器、移相器等电路中有很好的应用前景。     

18-42 GHz experimental verification of microstrip coupler and openend capacitance models

A cavity resonance technique is used to experimentally verify microstrip coupler and open end capacitance models over the frequency range of 18-42 GHz. In addition, these results are confirmed using an alternate version of the technique which directly determines open end discontinuity capacitance. In the second case, knowledge of substrate dielectric constant is not required, and the method also yields the microstrip relative effective dielectric constant     

Self consistent code for a 150 GHz gyrotron

A self consistent calculation for gyrotron oscillators is described and applied to a TE₀₃ mode gyromonotron. The RF field profile satisfies a wave equation in which the AC beam current appears as a source. The wave equation is solved simultaneously with the electron equation of motion.     

System characteristics of quasi-optical power amplifiers

Quasi-optical (QO) amplifiers have advanced to the point where they are competitive with other solid state and vacuum-based power amplifier technologies in the upper microwave and millimeter-wave bands. While still trailing in power-added efficiency, the QO amplifiers have advantages over traditional system architectures because of superior linearity, low noise, high spurious-free dynamic range, and added functionality (e.g., electronic beam steering). These advantages are stated in the present paper through a set of scaling laws that describe the behavior of fundamental amplifier properties versus the number n of elements in the QO array. It is known that the gain and power-added efficiency are scale independent, so that the output power scales as n ¹. Here we find that the white noise figure is scale independent and the 3rd order intercept point increases as n^3/2 . Hence, the spurious-free dynamic range (SFDR) should scale as n ¹.. This makes QO amplifiers attractive as "robust" low-noise amplifiers (LNAs) in traditional superheterodyne receivers. An analysis is carried out to predict the improvement in total SFDR of a superheterodyne receiver having a QO LNA at the front end     

Spectral and relaxation-time measurements in the HMBA CrV radical at 150 GHz

Spectral and relaxation characteristics of the HMBA Cr^V complex for polarized nuclear targets have been performed. Long time stability of the HMBA Cr^V complex in I.2 propylene glycol solution is investigated. Spin-lattice relaxation time and spectral diffusion rate versus concentration have been obtained.     

94 GHz回旋管准光模式变换器的数值模拟

对回旋管内置准光模式变换器进行了理论研究和数值模拟。基于几何光学理论和矢量绕射理论,编制了模拟电磁场行为的分析和优化程序,采用Vlasov辐射器和准光反射器实现了线极化准高斯模HE11。结果表明:在一级反射镜下的转换效率为88.3%,增加反射镜级数会降低转换效率。     

Hemispherical power gain pattern measurements at 7.5 GHz

A technique is described for measuring the complete hemispherical power-gain radiation pattern of a 2.44-m diameter paraboloidal reflector antenna mounted atop a mobile small earth terminal operating at 7.5 GHz. Antenna power-gain data were measured versus azimuth and elevation angles with the earth terminal centered on a heavy-duty turntable flush with test range ground.Test site illumination was achieved with airborne transmitting antennas. Conventional and statistical power-gain patterns are presented for left-hand circular polarization and cross polarization. Results indicate that similar systems cannot rely upon orthogonal polarization to provide isolation or compatibility beyond the angular region of the main lobe.     

（英）140GHz回旋行波管放大器准光学注入结构的设计

作为140GHz共焦波导回旋行波管放大器设计中的一个创新部分,关于准光学注入结构的设计方法将详细论述.归因于高斯光束对频率扰动的欠敏感特性,这样的注入结构具有比传统波导插入耦合器更大的带宽.注入系统包括耦合天线、镜面变换器和波纹波导三个部分,最终在高于50%功率注入水平下达到6.8GHz的带宽,并克服了可能的寄生模式振荡和由加工误差导致的注入效率迅速下降的问题.     

Quantum-well infrared photodetector structure synthesis: methodology and experimental verification

A numerical method for global optimization of quantum-well infrared photodetector (QWIP) performance parameters is presented and experimentally verified. The single-band effective-mass Schroedinger equation is solved by employing the argument principle method (APM) to extract both the bound and quasibound eigen-energies of the quantum heterostructure. APM is combined with a simulated annealing algorithm to determine a set of device design parameters such as potential barrier height V/sub i/, layer thickness d/sub i/, number of material layers N, total device length, applied bias V/sub Bias/ etc., for which the QWIP performance is within a predetermined convergence criterion. The method presented incorporates the effect of energy-dependent effective mass of electrons in nonparabolic conduction bands. The present model can handle many optimization parameters and can incorporate fabrication constraints to achieve physically realizable devices. In addition, the method is not limited to the optimization of absorption structures, and can be used for other intersubband devices such as electron-wave Fabry-Perot filters and quantum-cascade lasers. The strength and versatility of the present method are demonstrated by the design of a bicolor equal-absorption-peak QWIP structure, and experimental verification of the zero-bias absorption spectrum is presented.