Parametric Amplification of Space Charge Waves
Parametric Amplification of Space Charge Waves
复制标题
空间电荷波的参量放大
DOI：
10.1049/pi-b-1.1958.0140
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发表时间：
1958
期刊：
影响因子：
--
通讯作者：
C. Quate
中科院分区：
文献类型：
--
作者：
W. Louisell;C. Quate
在电路中使用可变电抗来产生增益的原理可以应用于电子束。该光束被频率等于信号频率两倍的RF波强烈调制。在这样的束流中，两个正常的空间电荷波在信号频率处分裂成两部分，一部分随距离呈指数增长，另一部分则衰减。无论是“慢”还是“快”的空间电荷波都可以放大。当这束先前以倍频调制的光束耦合到慢波电路时，就会发现不断增长的波，并再次放大“快”空间电荷波。我们强调快波的放大，因为适用于以前的微波放大器的噪声定理和建立噪声系数下限的方法不适用。因此，原则上，我们应该能够获得较低的噪声系数值。
The principle of using a variable reactance in a circuit to produce gain can be applied to an electron beam. The beam is strongly modulated by an rf wave at a frequency equal to twice the signal frequency. In such a beam the two normal space charge waves at the signal frequency break into two parts¿one grows exponentially with distance and the second is attenuated. Either the "slow" or the "fast" space charge wave can be amplified. When this beam, which has been previously modulated at the double frequency, is coupled to a slow wave circuit, growing waves are found and again the "fast" space charge wave can be amplified. We stress the amplification of the fast wave since the noise theorems which apply to previous microwave amplifiers and establish a lower limit to the noise figure do not apply. Thus, in principle, we should be able to obtain lower values for the noise figure.