Non-degenerate electron-beam parametric amplifiers

Ever since the Electron Beam Parametric Amplifier (EBPA) first became known, there has been substantial interest in the development of a nondegenerate version. The low-noise EBPA’ s now in use are degenerate or near-degenerate amplifiers;. the pump frequency which they employ is very nearly twice the signal frequency, with the resul t that an idler near the signal frequency is generated. In some situations this is harmless, but generally it represents a handicap. Solid-state diode amplifiers are usually nondegenerate, with a pump frequency many times higher than the signal frequency; an electron beam device employing such a frequency combination would have obvious advantages over its degenerate counterpart.