摘要:
本文提出一個用增加電極長度來提高微波場效應(yīng)器件輸出功率的新方法。從一個具有分布參數(shù)的電極系統(tǒng)模型出發(fā),求得一組描述電極系統(tǒng)上電流電壓與半導(dǎo)體中的電荷流的相互作用方程,這些基本方程以耦合模的形式表示。本文討論了弱耦合情況下的行波放大特性。在同步工作時,增益具有極寬頻特性,波幅沿漏極線上線性增長,功率輸出正比于電極的有源長度,并具有寬頻功率合成特性。在異步工作時,增益變?yōu)榈皖l窄帶特性。當(dāng)系統(tǒng)的電磁耦合存在時,系統(tǒng)中的波幅沿線路近似地按指數(shù)增長,并具有高增益特性。在合適的電極系統(tǒng)設(shè)計下,行波場效應(yīng)器件是可以實現(xiàn)大功率輸出,長壽命工作的。
Abstract:
A new method of increasing the power capability of microwave FETs by increas-ing the electrode length is proposed. An analytical model with distributed parameters of the structure is derived. A set of equations deseribing the mutual interaetion of voltage and eurrent on the electrodes with the charge current in the active layer of FET is found. This set of basie equations is transformed into coupled mode form. When the electromagnetic coupling is weak enough and in synchronous case, the wave amplification with ultra wide bandwidth occurs. The wave amplitude along the drain electrode system increases linearly with distance, the power output is directly proportional to the active drain electrode length. A broadband power combining exists. In nonsynchronous case, wave amplification shows only a narrow bandwidth. When the electromagnetic coupling cannot be neglected, the wave amplitude grows exponentially along the electrode length, indicating a high gain characteristic. the TW FET can be realized by proper design of the electrode system, and high power output with long life operation results.