基于微缩雷达应用的硅基毫米波片上天线

为研究小型化、微型化天线在现代无线应用中的集成趋势,对当前工艺水平下的毫米波段片上天线(AoC)设计进行了总结。从集成角度,对单片集成和混合集成的概念分别进行了优劣比较和讨论。作为一个单片集成技术方案的可靠候选,对硅基单片毫米波集成电路(SIMMWIC)技术进行了介绍,并给出了利用该技术实现的整流天线例子。通过单片集成的雪崩二极管发射机展示了如何利用三维电磁仿真工具设计及证明片上天线的性能,利用仿真和实际验证探讨了硅基毫米波片上天线的挑战和方法,为小型化雷达系统方案提供了一个稳固的基础。     

Characterization of IMPATT diodes at millimeter-wave frequencies

In order to evaluate the quality of a microwave device and to design a suitable circuit for it, the device must be characterized in terms of an equivalent circuit. At low microwave frequencies L through X bands, devices can be characterized in a relatively simple manner in conjunction with a coaxial transmission line network analyzer. At higher frequencies, such as millimeter-wave frequencies, however, the characterization must be carried out in a waveguide. This paper presents a technique for characterizing an IMPATT diode mounted in a waveguide and the associated circuit parasitics at millimeter-wave frequencies. The passive and active device parameters and the circuit parasitics, which have increased effects particularly at millimeter-wave frequencies, are evaluated by means of a computer-aided iterative curve-fitting method from the measured variation of the input impedance (VSWR) as a function of position of a movable short placed behind the device. The accuracy of the technique and the computer program are first checked by comparing the characteristics of anX-band IMPATT diode measured by the present technique and those measured by the network analyzer method. The characterization of a millimeter-wave IMPATT diode is then presented. A technique to achieve the stabilization required for the measurement of active parameters of the diode is also described. Comparison of the performance of an IMPATT diode amplifier calculated from the measured diode characteristics with the experimentally observed amplifier performance is then presented. It is shown that the device characterization technique can effectively be used for the analysis and design of a millimeter-wave circuit in which the device is used.     

Lateral IMPATT diodes

Conventional IMPATT diodes are the highest-power microwave semiconductor devices, but they are difficult to couple light into, challenging to integrate into monolithic circuits, to incorporate a third terminal, or to series combine. The lateral IMPATT diode is proposed as a solution to these problems. This device is planar and features contact and drift regions that are all adjacent to the wafer surface. Two types of fabrication schemes are discussed and pulsed RF power results, up to 17.4 GHz, are demonstrated. This device structure promises to be well suited for microwave, millimeter-wave, and electrooptic integrated circuits in which maximum power is required     

Impatt diode simulation

A set of programs is established for IMPATT (Impact Avalanche Transit Time) diode simulation. It can be used to obtain the DC small and large signal solution of the IMPATT diodes made of different materials and having different doping profiles. The physical principles, numerical methods and program design are discussed, and the half-implicit method is presented in detail. Those programs can be used to simulate all kinds of transit-time devices, but the calculation results only of the Si IMPATT Diode are given.     

Silicon high-resistivity-substrate millimeter-wave technology

The application of molecular beam epitaxy (MBE) and X-ray lithography for the fabrication of monolithic integrated millimeter-wave devices on high-resistivity silicon has been investigated. Process compatibility and the retention of high-resistivity characteristics were measured using the spreading resistance method and Hall measurements after various process steps. Microstrip resonators of ring and linear geometry were fabricated on 10 000 Ω.cm silicon substrates. For linear microstrip resonators, the attenuation was found to be less than 0.6 dB/cm at 90 GHz. A 95-GHz IMPATT oscillator circuit and a planar microstrip antenna array have been fabricated on highly insulating silicon substrates. For the oscillator, a combined monolithic-hybrid integration technique was used to attach the discrete IMPATT diode to the resonator circuit. The oscillator does not require tuning elements. Preliminary experimental results are 8 mW of output power with 0.2 percent efficiency at 95 GHz.     

High-frequency silicon-on-sapphire IMPATT oscillator

Epitaxially grown silicon-on-sapphire (SOS) monolithic integrated IMPATT oscillators were fabricated and tested. One diode was successfully operated under pulsed conditions yielding 10-mW peak power output at 13.8 GHz. This experiment serves to demonstrate the feasibility of silicon-on-sapphire monolithic integration at microwave frequencies.     

Estimation of power density in IMPATT using different materials

ABSTRACT

The RF output power dissipated per unit area is calculated using Runge-Kutta method for the high-moderate-moderate-high (n⁺-n-p-p⁺) doping profile of double drift region (DDR)-based impact avalanche transit time (IMPATT) diode by taking different substrate at Ka band. Those substrates are silicon, gallium arsenide, germanium, wurtzite gallium nitride, indium phosphide and 4H-silicon carbide. A comparative study regarding power dissipation ability by the IMPATT using different material is being presented thereby modelling the DDR IMPATT diode in a one-dimensional structure. The IMPATT based on 4H-SiC element has highest power density in the order of 10¹⁰ Wm^?2 and the Si-based counterpart has lowest power density of order 10⁶ Wm^?2 throughout the Ka band. So, 4H-SiC-based IMPATT should be preferable over others for the power density preference based application. This result will be helpful to estimate the power density of the IMPATT for any doping profile and to select the proper element for the optimum design of the IMPATT as far as power density is concerned in the Ka band. Also, we have focused on variation of power density with different junction temperatures and modelled the heat sink with analysis of thermal resistances.     

Oscillation Characteristics of Millimeter-Wave IMPATT Diodes Mounted in Low-Impedance Waveguide Mounts (Short Papers)

Experiments on dc-bias-current-tuned IMPATT diodes mounted in low-impedance waveguide mounts are described. Broad-band bias-current-tuned IMPATT oscillators were obtained which cover almost the full waveguide band; 20-, 24-, and 18-GHz tuning bandwidths were obtained with the R-500, R-620, and R-740 waveguide, respectively. From experiments it became evident that there are some suitable relations for broad-band bias tuning among the diode breakdown voltage, the oscillation frequency, and the waveguide dimension. The results are very useful for the design of the circuit and diode parameter for broad-band millimeterwave IMPATT sweep oscillators. The feasibility of applying bias-current-tuned IMPATT oscillators to a broad-band measuring instrument is expected.     

Oscillators and amplifiers in integrated E-plane technique

An overview is presented of solid-state oscillators and amplifiers realized in E-plane technology. The circuit topology, basic design procedures, and performance characteristics are described and compared. Gunn oscillators, IMPATT oscillators, transistor oscillators, injection-locked Gunn oscillators, and transistor amplifiers are surveyed. Gunn and transistor oscillators have been realized successfully for frequencies from 10 to 110 GHz, thus covering almost the entire frequency range suitable for E-plane technology. IMPATT oscillators are difficult to design and to reproduce in quasi-planar form because of the high impedance ratio that must be overcome by the circuit. E-plane FET amplifiers have been built for frequencies up to 60 GHz     

Large signal design of broadband monolithic microwave frequencydividers and phase-locked oscillators

This paper presents a design method for phaselocked devices such as frequency dividers or injection-locked oscillators. The method requires a full nonlinear analysis of the circuit. This analysis relies upon harmonic balance techniques and is suitable for monolithic circuits simulation. First, a modified formulation of the general harmonic balance equation is proposed which includes the presence of probes. These probes allow us to suppress the degenerated solution of the HB equation in autonomous cases. Moreover, a global stability analysis of phaselocked regimes is carried out. It provides invaluable information on the nonlinear behavior of the device. In particular, synchronization bandwidths as well as power ranges for which the circuit can be synchronized are obtained from the stability loci drawn in the parameter space. All these features have been used to design a broadband monolithic frequency divider, and the simulated and experimental results have been compared with very good accuracy. Therefore, the method proposed is a very useful tool for the design of potentially unstable circuits     

Junction-temperature measurement of IMPATT diodes

The breakdown voltage VB of an IMPATT diode is a function of the junction temperature. Pulse techniques are applied to measure VB directly during actual operation, thus giving the temperature within an accuracy of a few per cent. The method also provides a display of 'space-charge resistance at the operating temperature.     

Noise in IMPATT diodes: Intrinsic properties

The design of low-noise IMPATT diodes has been aided by theories describing the noise generation under small-signal conditions. A major deficiency in this procedure has existed in that there is no apparent connection between the small-signal behavior and the great increases in the noise observed in large-signal operation. As a remedy a theory has been developed for the noise generation at arbitrary signal levels by using a Read diode model. The theory is based on a linearization technique for calculating the spectrum of homogeneous noise with linear damping resulting in a separation of the large-signal and noise problems. The open-circuit noise voltage increases strongly at high signal levels due to nonlinear parametric interactions and gives rise to a rapid increase in the noise measure as a function of the generated microwave power. Operating parameters are derived that optimize the power-noise ratio. A long intrinsic response time is found to be beneficial in achieving high power as well as low noise. Other factors affecting the design and choice of material for IMPATT diodes are discussed. An important feature of the presented theory is that a complete design optimization with respect to the power-noise characteristics can be carried out provided reliable information exists about the ionization rates and the drift velocities. A simpler alternative is to obtain the physical quantities governing the power-noise behavior from small-signal admittance and noise measurements. Good agreement has been obtained with experimental power-noise measurements by this method. As an application of this procedure a state of the art comparison is given for GaAs, Ge, and Si diodes at 6 GHz.     

一种基于HP EESOF软件的IMPATT二极管非线性电路模型参数的提取方法

通过对雪崩二极管非线性电路模型参数数学表达式的分析，利用HPEESOF软件进行电路模型的计算机模拟，计算出雪崩管在非线性状态下的器件阻抗，从而为雪崩管振荡器的设计提供了重要的理论依据。     

Highly Reliable High-Power 86-GHz Components and Transmitter--Receiver Modules

The reliability of semiconductor active devices is related to the junction temperature of diodes used. This paper describes the reliability design and performance of 86-GHz active components and transmitter-receiver modules for a guided millimeter-wave transmission system. The components are IMPATT oscillators, IMPATT amplifiers, varactor frequency multipliers, and Schottky-barrier diode upconverters. The maximum output powers of these active devices are calculated for a given mean time between failure (MTBF). Active components and transmitter-receiver modules for 86-GHz operation were manufactured based upon the design with considerations for reliability as well as RF performance.     

Traveling-Wave IMPATT Amplifiers and Oscillators

Traveling-wave IMPATT oscillators and amplifiers are analyzed using a Iarge-signal transmission-line model. A specific case for a GaAs structure at 33.7 GHz is examined in detail. General equations relating to the design and expected power output from these devices are also developed. It is concluded that more RF power can he generated by traveling-wave structures than is obtainable from discrete IMPATT devices.     

Spurious oscillations in IMPATT oscillators

Incorrect circuit design of cavity-controlled IMPATT oscillators may cause low-frequency instabilities and frequency jumping, which are simply avoidable. A simple technique for identifying the avalanche resonance frequency of packaged IMPATT oscillators is also described.     

Heatsinking GaAs 4?18 GHz Gunn and IMPATT devices

A method for heatsinking high-power GaAs Gunn and IMPATT devices for the frequency range 4?18 GHz is described. The method is suitable for large-scale fabrication of devices, with high reproducibility and high quality. Typical microwave results are presented.     

Tunneling-assisted IMPATT operation

The influence of tunneling on the efficiency of millimeter-wave IMPATT diodes is investigated. For a reliable estimation of this influence, the tunnel generation rate coefficients are measured from silicon p-i-n diodes. The Read equation is solved taking a time-dependent tunnel current into account. The phase distortion, which is responsible for the efficiency degradation caused by tunneling, is calculated analytically and numerically. It is shown that for an exact solution the injected current density should be calculated numerically. The results suggest that for efficient silicon IMPATT diode operation, the maximum electric field should be below 1×10⁶ V/cm. Due to the current and field dependent representation of the injection phase, there are direct consequences on the design of millimeter- and submillimeter-wave transit time diodes for high power generation as well as for low-noise operation     

High-efficiency monolithic GaAs IMPATT diodes

Impedance-matching circuits were integrated on the same chip as the IMPATT diodes to produce monolithic impatt diodes for millimetre-wave applications. A drastic reduction of device-to-circuit parasitic elements was achieved by placing the external circuitry very close to the device. Oscillators fabricated in this fashion gave the highest efficiencies reported so far in the 30?35 GHz range with 28% conversion efficiency using hybrid-Read structures.