Packaging of MMICs in multilayer LCP substrates

A 13-25-GHz GaAs bare die low noise amplifier is embedded inside a multilayer liquid crystal polymer (LCP) package made from seven layers of thin-film LCP. This new packaging topology has inherently unique properties that could make it an attractive alternative in some instances to traditional metal and ceramic hermetic packages. LCP is a near-hermetic material and its lamination process is at a relatively low temperature (285/spl deg/C versus >800/spl deg/C for ceramics). The active device is enclosed in a package consisting of several laminated C0/sub 2/ laser machined LCP superstrate layers. Measurements demonstrate that the LCP package and the 285/spl deg/C packaging process have minimal effects on the monolithic microwave integrated circuit radio frequency (RF) performance. These findings show that both active and passive devices can be integrated together in a homogeneous laminated multilayer LCP package. This active/passive compatibility demonstrates a unique capability of LCP to form compact, vertically integrated (3-D) RF system-on-a-package modules.     

Third-order intermodulation distortion in microwave amplifier

Third-order intermodulation distortions of a microwave GaAs f.e.t. amplifier are analysed using a simple nonlinear model for the device. If the amplifier has strong feedback at low frequencies, the second-order interactions may dominate and degrade the third-order distortions. Solutions are presented to eliminate this distortion degradation. The analysis is very well substantiated by measurements.     

A microwave Doherty amplifier employing envelope tracking technique for high efficiency and linearity

In this letter, we demonstrate a microwave Doherty amplifier employing an input signal envelope tracking technique. In the amplifier, the gate bias of the peaking amplifier is controlled according to the magnitude of the envelope. A 2.14-GHz Doherty amplifier is implemented using 4-W PEP LDMOSFETs, and an adaptive controlled gate bias circuit is constructed and the control shape is optimized experimentally. The performance of the microwave Doherty amplifier is compared with that of a class AB amplifier using one-tone, two-tone, and forward-link wideband code-division multiple access (WCDMA) signals. For a forward-link WCDMA signal, the measured power added efficiency (PAE) of the microwave Doherty amplifier is 39.4% at -30 dBc adjacent channel leakage ratio (ACLR), while that of the comparable class AB amplifier is 24.2% at the same ACLR level.     

A High-Power $Ka$-Band (31–36 GHz) Solid-State Amplifier Based on Low-Loss Corporate Waveguide Combining

A method of using low-loss waveguide septum combiners is developed into a high-power $Ka$-band (31–36 GHz) amplifier producing $>$50 W at 33 GHz ($Ka$-band) using 32 low-power ($≪$2 W) solid-state amplifier modules. By using low-loss waveguide combining and a packaged monolithic microwave integrated circuit with a low-loss microstrip-to-waveguide launcher, the output loss is minimized, allowing for the overall power-combining efficiency to remain high, $>$80% (average insertion loss of combiner $≪$ 0.7 dB and average insertion loss of launcher $≪$0.3 dB) over 31–36 GHz. In the past, lower power-combining efficiencies have limited the number of modules that can be combined at $Ka$ -band, and hence, have limited the power output. The approach demonstrated in this paper, with high power-combining efficiency, allows a very large number (32) of solid-state amplifier modules to be combined to produce high powers. Greater than 50 W was demonstrated with low power modules, but even higher powers $>$120 W are possible. The current approach is based on corporate combining, using low-loss waveguide septum combiners that provide isolation, maintaining the true graceful degradation of a modular solid-state amplifier system.      

An MMAC C-band FET feedback power amplifier

A feedback power amplifier using miniaturized microwave active circuit (MMAC) technology was developed for satellite C-band applications. This design demonstrates that a strong negative feedback can be implemented in the microwave frequencies to improve amplifier linearity and output power over a 750 MHz bandwidth. The amplifier provides a third-order intermodulation distortion improvement of 7 to 9 dB across the band at backoff, compared to results obtained using the conventional approach without feedback. The theory, proof-of-concept experiment, design, and MMAC implementation of the feedback amplifier are presented     

Cryogenic noise performance of HEMTs and MESFETs between 300 and700 MHz

The authors present the noise performance of amplifiers using HEMTs and MESFETs at room temperature and cryogenic temperatures, in the frequency range 300-700 MHz. Results demonstrate that these microwave devices can be applied at frequencies down to at least 300 MHz, giving amplifier noise temperatures below 2 K at 20 K ambient temperature     

Development of Thin-Film Liquid-Crystal-Polymer Surface-Mount Packages for $Ka$ -Band Applications

In this paper, we present the design and development of thin-film liquid-crystal-polymer (LCP) surface-mount packages for $Ka$ -band applications. The packages are constructed using multilayer LCP films and are surface mounted on a printed circuit board (PCB). Our experimental results demonstrate that the package feed-through transition including a PCB launch and bond wires achieve a return loss of better than $-$20 dB and an insertion loss of less than 0.4 dB around $Ka$ -band. We achieve a measured port-to-port isolation of the package to be more than 45 dB across the $Ka$-band. We demonstrate the package feed-through circuit model by comparing the simulation of model and bare die measurement data to a packaged amplifier measurement. Finally, we report an LCP cavity that has a measured fine leak rate of ${hbox{3.6}}times {hbox{10}}^{-8} {hbox{atm}}cdot{hbox{cc/s}}$ .      

GaAs Fet Ultrabroad-Band Amplifiers for Gbit/s Data Rate Systems

A novel ultrabroad-band amplifier configuration suitable for GaAs FET's has been developed. The developed amplifier circuit operates as a capacitor-resistor ( C-R ) coupled mnpfifier circuit in the low-frequency range in which |S/sub 21/| for the GaAs FET's is constant. It also operates as a lossless impedance matching circuit in the microwave frequency range in which |S/sub 21/| for the GaAs FET has a slop of approximately -6 dB/octave. Using this configuration technique, 800-kHz 9.5-GHz band (13.5 octaves), 8.6-dB gain GaAs FET amplifier modules have been realized. The amplifier module has 40-ps step response rise time. It also has low input and output VSWR. By cascading two-amplifier modules, 19-dB gain over the 800-kHz to 8.5-GHz range and 50-ps step response rise time were obtained. NF is lower than 8 dB over the 50-MHz to 6-GHz range.     

A 30 GHz MMIC receiver for satellite transponders

The development of 30-GHz-band monolithic microwave integrated circuits (MMICs) and multichip MMIC modules (low-noise amplifier and frequency converters) is reported. A 30-GHz-band full-MMIC receiver for satellite transponders was successfully constructed using the MMIC modules and the performance of the full-MMIC receiver is evaluated. Test results verify its successful performance as a satellite receiver system. The design and performance of the MMICs (a two-stage amplifier, an image rejection mixer, and a frequency multiplier), of multichip-type MMIC modules (a 30-GHz-band low-noise amplifier module with 30 dB gain and 8.2 dB noise figure, and an image rejection frequency converter with a 10 dB conversion loss and an 18 dB image rejection ratio) and of the full-MMIC receiver, which weighs 1/6 as much as a conventional hybrid integrated circuit are presented     

0-40 GHz GaAs MESFET distributed baseband amplifier ICs forhigh-speed optical transmission

We describe distributed amplifiers built using advanced circuit design techniques to improve gain and noise performance at low frequencies. Using these techniques we have developed an amplifier IC with a 0-36 GHz bandwidth and a noise figure of 4 dB at low frequencies. This frequency range starting from 0 Hz makes it possible to use the IC as a baseband amplifier for SDH optical transmission systems and this noise figure is about 1 dB better than conventional distributed amplifiers. We also present another amplifier IC built using our loss compensation technique to improve high-frequency performance of the amplifier. This IC has a 0-44-GHz bandwidth, which is the widest among all reported GaAs MESFET baseband amplifiers     

Accurate RF electrical characterization of CSPs using MCM-D thin film technology

The thin film multilayer multichip module-deposited (MCM-D) technology of IMEC is used for characterising the RF electrical performance of two types of chip scale packages (CSPs). The measurement technique called MCM-on-package-on-MCM (MoPoM) enables accurate measurements and de-embedding in the gigahertz (GHz) range of frequencies. Wafer processing of the MCM-D technology allows for several design structures to be integrated on a single mask. The packages chosen are a 120-pin plastic ball grid array (PBGA) and an 80-pin polymer stud grid array (PSGA). Lumped element models extracted from measurements and three-dimensional simulations show good agreement with the measurements up to 6 GHz for the BGA and the PSGA. The electrical performance of the packages is compared at 1.8 GHz (GSM), 2.4 GHz (Bluetooth), and 5.2 GHz (HiperLAN) and at 5.2 GHz both the packages exhibit a return loss of lower than -10 dB and hence cannot be used in most cases without design improvement. We also show that the influence of encapsulant is significant while transmission line detuning due to the package is not significant at microwave frequencies. We also briefly mention about the crosstalk effects. We demonstrate the significant degradation in the performance of a 5.2 GHz MCM-D low noise amplifier (LNA) after packaging. A significant improvement in package performance is observed by conjugate matching the package interconnects.     

三维微波多芯片组件垂直微波互联技术

三维微波多芯片组件是新一代固态有源相控阵共形天线和智能蒙皮的核心部件。文章详细介绍了实现三维微波多芯片组件最关键的小型化、低插入损耗和高可靠的垂直微波互联技术,对采用毛纽扣结构的无焊接垂直微波互联和采用环氧树脂包封的垂直微波互联、微波传输结构进行了仿真和优化,研发出相应的制作工艺,实现了三维微波多芯片组件微小型化、大工作带宽、低插入损耗和高可靠垂直微波互联。     

Characterization of a low-noise linearized microwave power amplifier module

An X-band, low-noise, linearized microwave power amplifier module consisting of a low-noise solid-state amplifier (SSA), predistortion linearizing circuit, and low-gain helix traveling wave tube (TWT) is designed and tested in order to demonstrate both reduced noise figure and suppressed intermodulation distortion ratio. Two-tone intermodulation distortion (IMD) ratios are predicted from simulations obtained from modeling of the TWT, linearizing circuit, and SSA by the use of Agilent's Advanced Design System simulation code. Simulated IMD ratios are in good agreement with measured results. Measurements show a noise figure of 2.2 dB at 9.5 GHz and the third-order IMD ratio of -53 dBc at 10 dB input back off from the input P1dB point. It is found that both noise figure and IMD ratio are significantly improved compared with conventional helix-TWTs and microwave power modules.     

Reducing feed-through effect within envelope elimination and restoration transmitters

Proposed is a new configuration of an envelope elimination and restoration (EE&R) transmitter designed to reduce the feed-through effect within an EE&R transmitter. Combining the feed-through elimination circuit with a baseband predistorter results in an amplifier with a first adjacent channel power ratio of -55 dBc.     

光调制解调器的设计与实现

研制了一种光调制解调器,该光调制器是由高频DFB激光二极管组件与APC电路、ATC电路组成,光纤传输线为5km光纤;光解调器是由高速跨阻放大器的PD组件与宽带低噪声放大器组成.系统实现了宽带微波信号的高线性、低失真、远距离光纤传输.     

RF Class-E Power Amplifier Design Based on a Load Line-Equivalent Capacitance Method

In this research work, an alternative methodology to design radio frequency (RF) class-E amplifier is proposed and verified. The conventional design procedure starts with a switch idealization of the device and extraction of the output capacitance based on S parameter measurements. Since these ideal conditions lead to non-optimal values at microwave frequencies, an optimization procedure on these values, using a non-linear model of the device, has to be applied in order to obtain higher performance. Unlike this legacy procedure, the proposed method starts the design of the RF class E power amplifier with the non-linear model directly to determine a more representative value of the equivalent capacitance, and thereby considering all the non-ideal and non-linear features of the device.     

A comparative study on the various monolithic low noise amplifiercircuit topologies for RF and microwave applications

This paper critically compares the various monolithic low noise amplifier (LNA) circuit topologies using BiCMOS or MESFET technologies for RF and microwave applications, in addition to the conventional techniques, five newly proposed schemes for the simultaneous noise and input power matching are extensively compared with each other at microwave frequencies. At L-band, the best scheme is found to be the proposed cascode inductive series feedback (CCSF) or common-source inductive series feedback (CSSL)+common-gate inductive parallel feedback (CGPF) when 0.5 μm GaAs MESFET is used, while it is cascode resistive parallel feedback (CCPF) when n-p-n BJT is used. At C- and X-bands, the proposed CGPF exhibits the best performance. Other than CGPF, the CSSL+CGPF seems to he the best at 6 GHz, and both CCPF+CGPF and CSSL+CGPF are recommended at 12 GHz. Finally, to verify the feasibility of this approach, a CCPF has been fabricated with 0.5 μm GaAs MMIC technology, of which measured results agree well with the simulated ones     

毫米波50W 连续波固态发射机的设计与实践

随着微波固态功率器件和单片集成电路的发展,雷达、制导和通信等向更高频段扩展,大功率毫米波 固态功放已成为国内外业内人士的主攻方向。文中介绍了一种毫米波50W 连续波固态发射机,设计了一种紧凑高 效率的新型微带贴片与波导双模空间耦合功率合成电路,合成效率大于89%。文章详细描述了发射机中功放模块 的电路设计、功放芯片的贴装、键合等关键技术。以往电路设计中往往忽略了由于金丝键合引入感抗而导致电路性 能指标下降,因此对金丝键合给电路所带来的影响及其解决途径作了分析。文章还介绍了该发射机的控制检测、保 护等电路与冷却结构设计。发射机的性能完全满足指标要求,并已成功用于整机之中。以其中的功率模块为基础, 可以构成更大输出功率的毫米波固态发射机。     

Power-amplifier modules covering 70-113 GHz using MMICs

A set of W-band power amplifier (PA) modules using monolithic microwave integrated circuits (MMICs) have been developed for the local oscillators of the far-infrared and sub-millimeter telescope (FIRST). The MMIC PA chips include three driver and three PAs, designed using microstrip lines, and another two smaller driver amplifiers using coplanar waveguides, covering the entire W-band. The highest frequency PA, which covers 100-113 GHz, has a peak power of greater than 250 mW (25 dBm) at 105 GHz, which is the best output power performance for a monolithic amplifier above 100 GHz to date. These monolithic PA chips are fabricated using 0.1-μm AlGaAs/InGaAs/GaAs pseudomorphic T-gate power high electron-mobility transistors on a 2-mil GaAs substrate. The module assembly and testing, together with the system applications, is also addressed in this paper     

Role of radar in microwaves

Radar has been highly influenced by the technology of microwaves, and likewise the development of microwaves has been significantly affected by the needs of radar. This paper addresses the relation between the two. It begins by briefly describing the introduction of microwave radar in World War II that was a major factor in the Allies achieving success in air defense and antisubmarine warfare. Microwave radar developments during and after the war are reviewed, along with a listing of current military and civilian applications. The dependence of modern radar on digital processing (with clock rates at microwave frequencies), high-power transmitters, and sophisticated antennas is discussed. The paper concludes by mentioning possible future directions for radar, and briefly describes two examples of future radar system opportunities. These are the ubiquitous radar and high-power transportable millimeter-wave radar based on the gyroklystron amplifier. The message is that microwaves and radar have mutually benefited from one another and that radar still offers many opportunities for microwave engineers to demonstrate their ingenuity and creativity