A non-degenerate electron beam parametric amplifier

In a non-degenerate electron beam parametric amplifier (EBPA), signal and idler frequencies are far apart. This contrasts with the more familiar degenerate type which uses a pump frequency approximately equal to twice the signal frequency, thus placing the idler near the signal. The non-degenerate EBPA shares with its better-known degenerate counterpart some desirable properties, such as unilateral amplification and the ability to take high overload; in addition, it is a single-channel device. On the other hand, it is more difficult to construct.