超突变结变容管的模型研究

在改进的超突变结变管掺杂分布模型的基础上，对超突变结的雪崩击穿电压进行了理论研究，并用二分法得到了通常实用范围的Ｖｂ，Ｎｏ数据表；同时用牛顿迭代法进行了数值求解，得出了归一化的Ｃ－Ｖ和Ｗ－Ｖ数据表。     

超突变结变容二极管的杂质浓度分布及n值

讨论了国产和进口超突变结变容二极管的杂质浓度分布和n值,提出了提高国产超突变结变容二极管性能的措施.     

变容二极管的新发展及其应用

评述当前变容二极管的新动态，如大电容比、双离子注入、嵌入到调谐器中、多管芯化、超小型化、低电压化和应用多样化等。     

超突变结变容管的设计模型

通过建立一种超突变结变容二极管的杂质浓度分布模型,并基于求解一雏泊松方程、雪崩击穿条件方程和电阻计算公式,推导了该模型的C-V特性、VBR、Rs和Q值,设计了用于分析该模型的模拟软件,阐述了模拟软件的运行流程.基于该模型和模拟软件,采用外延-扩散的方法研制了一种硅超突变结变容二极管,采用C-V法测量了外延材料的杂质浓度分布,结果表明材料的浓度分布与模拟结果相符.研制的变容二极管的主要参数:击穿电压VBR为50～55 V;电容变化比(C_4v/C_8v为2.42～2.44;VR=-4 V,f=50 MHz时的品质因素Q为150～180,实测参数与模拟结果吻合得很好.设计模型和模拟软件得到了验证.     

一种新的超突变结电容电压方程

本文对超突变结构变容二级管进行了深入的研究，在改进的杂质分布模型基础上，推出一种新的超突变结构电容电压特性方程，方程中的主要参数与实际工艺参数一致，解决了以在模型这方面的不足。     

新模型基础上的超突变结变容管容压变化指数

在一种新改进的超突变结变容管杂质分布模型的基础上,对变容管的容压变化指数ｎ与器件的材料和工艺参数之间的关系进行了研究,根据导出的关系进行了数值计算,并绘出实用的关系曲线图。     

超突变结变突二级管的杂质浓度分布及n值

讨论了国产和进口超突变结构容二极要质浓度分布和ｎ值，提出了提高国产超突变结变容二极管性能的措施。     

超突变结变容管容压变化指数的研究

应用改进的超突变绿变容管杂质分布模型，对以杂质分布的不同参起来 特征的容压变化指数ｎ进行了数值计算并绘成了关系曲线图。     

MOCVD生长超突变结GaAs变容管材料

用ＭＯＣＶＤ生长了用于ＧａＡｓ变容二极管的结构材料。分别用ＳｉＨ＿４和ＣＣｌ＿４作为掺杂剂对ＧａＡｓ进行ｎ型和ｐ型掺杂，找到了适合高质量变容管材料的方法．材料用于器件制作，得到了反向击穿电压大于２５Ｖ、电容变化比大于４０的变容管。     

Hyperabrupt Junction Varactor Diodes for Millimeter-Wavelength Harmonic Generators

The design of a hyperabrupt Schottky-barrier varactor is considered with an exponentially retrograded doping profile assumed. Resistance and capacitance models are used to determine optimum doping profile characteristic length and breakdown voltage with respect to device dynamic cutoff frequency. Device fabrication is discussed and test results are presented indicating conversion efficiencies of approximately 15 percent upon doubling to the 200-GHz frequency range.     

Design and Analysis of Frequency-Tunable Amplifiers using Varactor Diode Topologies

The design of frequency-tunable amplifiers is investigated and the trade-off between linearity, efficiency and tunability is revealed. Several tunable amplifiers using various varactor diode topologies as tunable devices are designed by using load-pull techniques and their performances are compared. The amplifier using anti-series distortion-free varactor stack topology achieves 38% power added efficiency and it may be tuned from 1.74 to 2.36 GHz (about 35% tunable range). The amplifier using anti-series/anti-parallel topology is tunable from 1.74 to 2.14 GHz (about 23% tunable range) and provides 42% power added efficiency. It is demonstrated that tunable amplifiers using distortion-free varactor stack topologies provide better power added efficiency than the tunable amplifiers using reverse biased varactor diodes and their linearity is similar to that of a conventional amplifier. These amplifiers may facilitate the realization of frequency agile radio frequency transceiver front-ends and may replace several parallel connected amplifiers used in conventional multimode radios.     

Investigations of Broad-Band, Linear Phase Shifters Using Optimum Varactor Diode Doping Profiles

The problem of obtaining linear phase shift of microwave signals over a broad frequency range and its dependence on varactor properties is addressed. An important application of the linear phase shifter, the microwave frequency translator, is investigated in detail and various circuit configurations and varactor doping profiles are examined relative to their performance including suppression of undesired frequency components and bandwidth. Hyperabrupt or Read-type varactor diodes are found to be very useful in this application     

应用于三维IC的积累型NMOS变容二极管

基于TSV技术,提出了一种应用于三维集成电路的积累型NMOS变容二极管.通过与传统积累型NMOS变容二极管对比,证明了基于TSV的积累型NMOS变容二极管具有电容密度大、集成度高的优点.分析了 TSV高度、TSV直径、源区和漏区结深、源区和漏区宽度对所提出变容二极管性能的影响.结果表明,通过增加TSV高度或增大TSV直...     

Variable Bandpass Filters Using Varactor Diodes

A rectangular waveguide type variable bandpass filter for the 4-GHz bandpass has been proposed and tested. The bandpass width varies from 260 MHz to 1.02 GHz for a filter using varactor diodes. Two microstrip variable bandpass filters for the 6-GHz and 4-GHz bands are also proposed and tested. The passband width varies from 310 MHz to1.24 GHz for a varactor-diode coupled filter, and it varies from 380 MHz to 2.18 GHz for a filter which is composed of low-pass and high pass filters connected in cascade. The center frequency of the three filters can be changed arbitrarily.