Novel microcontacts in microwave chip carriers developed by UV-liga process part II

This paper presents the design and development of novel type microcontacts in monolithic microwave integrated circuit (MMIC) chip-carriers to printed circuit board (PCB) assembly. Several new concepts of microcontacts for packaging solutions of microwave and millimeter-wave MMIC are depicted. Simulation and vector network analyzer (VNA) measurement results for these microcontact transitions are discussed. The results show that the electrical parameters are highly dependent on the transition dimensions and substrate features. These contacts are based on male stud (bump) and female (ring) concept. When mating each other, there are clips effect and self-alignment features. Special attention is paid to the shape of the microcontacts in order to facilitate assembly and strengthen the connection. Equivalent electrical circuit is proposed for PSPICE simulation of the dc contact resistance. Finally, the article discusses the technological implementation of the proposed new microcontact stud-ring through low-cost ultraviolet electroplating, lithography, and molding (UV-LIGA) process and the regime influence on the shape, geometry, and mating capabilities. Results from mechanical pull and adhesion tests are also discussed.     

A CAD-suitable approach for the analysis of nonuniform MMIC andMHMIC transmission lines

A new method of moment-based formulation for the solution of the telegraphist's equations in nonuniform transmission lines is presented. Entire domain basis functions that build in a frequency variation are used to cover wider frequency and physical dimension ranges. The results obtained using the proposed formulation are validated by comparison to those obtained by a CAD package and to measured data. Different nonuniform lines in microstrip and coplanar technologies on monolithic microwave/millimeter wave integrated circuit (MMIC) and miniaturized hybrid microwave integrated circuit (MHMIC) substrates are investigated with an application to the design a matched taper transition in a MMIC coplanar line     

Contact resistance calculations: generalizations of Greenwood'sformula including interface films

The calculation of the contact resistance between two rough electrodes is a difficult task, since the contact interface comprises many spots corresponding to more or less conducting paths for the electrons. The present paper starts with an analytical formula derived by J.A. Greenwood (1966) to find the electrical resistance of a cluster of perfect circular microcontacts. It is first shown that Greenwood's formula can be used to derive known and new formulas for the constriction resistance of single spots of various shapes. Then we consider the case where the microcontacts are not perfect, and characterize each microcontact by a film resistance. To generalize Greenwood's formula, we use an intermediate expression derived by this author, and substitute for the constriction resistance term of each spot, a term comprising the constriction resistance and the film resistance. We then test the formulas proposed. In all situations the electrical contact area is modeled by means of a set of square spots. At first, we consider experimental results concerning long rectangular spots. Then, we consider numerical results concerning square ring-shaped spots. And lastly, we consider the ease where two large electrodes communicate through two concentric thin flat rings of variable conductivity. The contact resistance is then calculated using Greenwood's generalized formula and by means of the finite-element method. All tests are passed satisfactorily     

GaAs微波单片集成电路(MMIC)的可靠性研究

本文介绍了GaAs MMIC的可靠性研究与进展，重点介绍了工艺表征工具（TCV）、工艺控制监测（PCM）和统计工艺控制（SPC）等实现产品高质量、高可靠性和可重复性的可靠性保障技术，为国内GaAs MMIC可靠性研究提供了新的思路。     

MMIC毫米波倍频器的研究

在介绍倍频器工作原理、各种实现方法及其优缺点的基础上,阐明了采用MMIC(单片微波集成电路)工艺实现高性能、高可靠性、小型化毫米波倍频器芯片的技术特点及应用需求,比较了单管和平衡两种不同结构MMIC毫米波倍频器的优点与不足,全面综述了国内外对MMIC毫米波倍频器的研究情况,介绍了MMIC毫米波倍频器的最新研究进展,展望了MMIC毫米波倍频器的发展趋势,提出了一些建议。     

发展氮化镓集成电路的考虑

介绍了氮化镓微电子器件的优势和现状。提出将GaNHEMT作为微波器件用于混合微波集成电路(MIC)和微波单片集成电路(MMIC),在射频输出功率、器件优值等方面,均具有明显优点,并列举了成功的例子。为了加快发展MMIC,必须解决好几个关键问题,即提高材料质量和尺寸,完善制造工艺,克服器件电流下降、增益过早饱和与射频输出功率退化等现象。     

基于RC-CR多相网络的镜频抑制接收机MMIC

基于RC-CR多相网络技术研制了一款S波段镜频抑制接收机单片微波集成电路(MMIC),在MMIC芯片上集成S波段低噪声放大器(LNA)、差分IQ混频器、本振(LO)驱动放大器、RC-CR多相网络滤波器等电路单元,实现了S波段单片镜频抑制接收机,解决了镜频接收机小型化的问题.电路、电磁场软件仿真以及采用GaAs赝配高电子迁移率晶体管(PHEMT)工艺流片后的结果表明,在S波段实现了噪声系数小于1.8 dB,增益大于12 dB,中频(150±5) MHz带内镜频抑制大于35 dBc的技术指标.MMIC的芯片尺寸为4.8 mn×2.5 mm×0.07 mm.此镜频抑制接收机MMIC具有指标优异、体积小、集成度高的特点,可广泛用于各种需小型化的相控阵雷达和通信系统中.     

The evolution of packages for monolithic microwave andmillimeter-wave circuits

The maturing of monolithic microwave integrated circuit (MMIC) technology has spawned a variety of new military and commercial applications. As-a result, there is an increased emphasis on the packaging of MMIC chips and MMIC-based components. Currently, the industry is applying a number of new assembly and packaging technologies to RF components and subsystems driven by the forces of performance, size and weight, and cost. This paper outlines the current evolution in microwave and millimeter-wave packaging using examples drawn from the area of active array antennas     

微波固态器件与单片微波集成电路技术的新发展

对不同时代的单片微波集成电路(MMIC)的器件工艺发展和应用发展状况进行概况总结,并结合当前的研究与应用热点,重点分析以砷化镓(GaAs)、氮化镓(GaN)为代表的微波化合物固态器件和基于MMIC的异构异质集成新技术路径,并就今后发展的趋势做出展望.     

Improved planar spiral transformer theory applied to a miniaturelumped element quadrature hybrid

In this paper, an improved method of determining the primary-to-secondary coupling capacitance for planar spiral transformers (PST's) is presented, which enhances previous work. A more general monolithic microwave integrated circuit (MMIC) compatible lumped element multisection model is also presented based on symmetric-width uniformly coupled transmission lines. These techniques were developed to design a 90° hybrid as a MMIC with a center frequency of 2.5 GHz. The design was frequency scaled to 0.5 GHz and fabricated in the microwave integrated circuit (MIC) for verification. Producibility is enhanced and coupling is effectively increased with the novel use of series capacitors which cancel some of the self-inductance of the transformers. Measured results are presented for both a quadrature hybrid and the individual PST used in the quadrature hybrid. The measured results show excellent agreement with the computer models     

Real-time linear time-domain network analysis using picosecondphotoconductive mixer and samplers

Ion-implanted GaAs photoconductive (PC) switches have been used as an optical-microwave frequency mixer and electrical waveform samplers in a real-time sampling system. This high fidelity system has a bandwidth of 100-GHz, time resolution of 4-ps and a measurement sensitivity of 5-μV/√(Hz). Because of this high sensitivity capability, the magnitude of the testing signal can be maintained sufficiently small to allow network analysis of a device or circuit in the linear mode without signal distortion. In this paper, a linear time-domain network analysis of a broadband monolithic microwave integrated circuit (MMIC) amplifier has been demonstrated in real-time by the optoelectronic technique. A measurement time of less than 40 μs is used to acquire waveform data. The dynamic range of the system can be further improved to 40 dB by reducing the repetition rate of the step recovery diode. Since the PC switches are fabricated with processes compatible to MMIC manufacturing, this real-time system is well-suited for on-wafer MMIC characterization     

Single-MMIC four-channel transmitter module for multichannelRF/optical subcarrier multiplexed communications applications

Presents a compact single monolithic microwave integrated circuit (MMIC) transmitter module for four-channel RF/optical subcarrier multiplexed (OSCM) communication applications. The developed module consists of one fully monolithic four-channel OSCM transmitter integrated circuit (IC) and four coupled-line filters. The MMIC is designed and implemented in a commercial 0.6-μm GaAs MESFET process and five-stage coupled-line filters are fabricated for each of the four channels on the module board. The module design and bit-error-rate performance are considered. This is the first fully monolithic IC transmitter module for OSCM communications applications     

Highly integrated three-dimensional MMIC technology applied tonovel masterslice GaAs- and Si-MMICs

A novel three-dimensional (3-D) masterslice monolithic microwave integrated circuit (MMIC) is presented that significantly reduces turnaround time and cost for multifunction MMIC production. This MMIC incorporates an artificial ground metal for effective selection of master array elements on the wafer surface, resulting in various MMIC implementations on a master-arrayed footprint in association with thin polyimide and metal layers over it. Additionally, the 3-D miniature circuit components of less than 0.4 mm² in size provide a very high integration level. To clearly show the advantages, a 20-GHz-band receiver MMIC was implemented on a master array with 6×3 array units including a total of 36 MESFETs in a 1.78×1.78 mm area. Details of the miniature circuit components and the design, closely related to the fabrication process, are also presented. The receiver MMIC exhibited a 19-dB conversion gain with an associated 6.5-dB noise figure from 17 to 24 GHz and an integration level four times higher than conventional planar MMICs. This technology promises about a 90% cost reduction for MMIC because it can be similarly applied to large-scale Si wafers with the aid of an artificial ground     

Time-domain finite difference approach to the calculation of thefrequency-dependent characteristics of microstrip discontinuities

The frequency-dependent characteristics of the microstrip discontinuities have previously been analyzed using full-wave approaches. The time-domain finite-difference (TD-FD) method presented here is an independent approach and is relatively new in its application for obtaining the frequency-domain results for microwave components. The validity of the TD-FD method in modeling circuit components for MMIC CAD applications is established     

X和Ku波段GaAs MMIC低噪声放大器的测量及其研究

讨论了微波电性能测量在ＧａＡｓＭＭＩＣ研制和开发中的重要作用，研究了Ｘ和Ｋｕ波段ＧａＡｓＭＭＩＣＬＮＡ微波电性能测量及其测量系统设计所要注意的有关问题。给出了相关增益、噪声系数、输入和输出驻波比的测试结果，并介绍了这两个频段ＧａＡｓＭＭＩＣＬＮＡ的应用情况。     

Si基微波单片集成电路的发展

随着半导体制造技术和材料技术的进步,Si基微波单片集成电路逐渐向高频、高线性、低噪声、低成本方向发展。介绍了近年国内外在Si基微波单片集成电路在制造工艺、电路结构和制作材料上的革新,阐述了三维Si微波单片集成电路技术、隔离槽技术、Si高阻衬底技术、SiGe技术等对Si基微波单片集成电路发展的影响,并列举了一些典型的应用。最后展望了Si基微波单片集成电路的发展前景。     

The nature of the charges, currents, and fields in and aboutconductors having cross-sectional dimensions of the order of a skindepth

The nature of the charge, current, and field patterns is investigated in and about transmission-line conductors operating in a frequency range where one or more of the cross-sectional dimensions of the conductors is on the order of a skin depth. Questions are addressed concerning whether quasi-TEM (transverse electromagnetic) approximations can be used. Examples which simulate the relatively lossy, longer on-chip interconnects in high-speed digital circuits are considered. For comparison, approximations to monolithic microwave integrated circuit (MMIC) line examples, which usually have larger cross-sectional dimension and hence are less lossy, are also examined     

Development of MMIC-based modules for multichannel RF/opticalsubcarrier multiplexed communications applications

We present a C-band monolithic microwave integrated circuit (MMIC) transmitter module development for multichannel RF/optical subcarrier multiplexed (OSCM) communication applications. The C-band MMIC transmitter module consists of one fully monolithic four-channel OSCM transmitter IC and four coupled-line filters. This MMIC is designed and implemented in a commercial GaAs MESFET process and coupled line bandpass filters are fabricated on the module board. We present the design and performance of the first fully monolithic IC transmitter module for OSCM packet switched applications     

Modified broadside-coupled microstrip lines suitable for MIC andMMIC applications and a new class of broadside-coupled band-pass filters

Modified broadside-coupled microstrip lines, suitable for microwave and millimeter-wave integrated and monolithic integrated circuit (MIC and MMIC) applications requiring wide bandwidths and tight couplings, are presented. Their analysis, based on the quasi-static spectral domain technique, is described. Using these broadside structures, a new class of broadside-coupled band-pass filters has been developed at X-band (8-12 GHz) with about 1-dB insertion loss. Fair agreement between the measured and calculated results has been observed even though a major approximation is used