Parametric travelling-wave amplification along three transmission lines coupled by diode quartets

Each of the three waves (pump, signal, and idler) is transmitted along an independent line of appropriate characteristic impedance coupled only by equidistant reactance-diode quartets. Such a quad is composed of four diodes mounted in one plane perpendicular to the direction of wave propagation and connected as a ring-type modulator. The three transmission lines consist of a rectangular waveguide with Lecher wires parallel to its axis. The pump wave (8.45 Gc/s) is transmitted in a waveguide mode through the waveguide, the idling wave (5 Gc/s) in the Lecher mode along the double conductor. The signal wave (3.45 G/s) propagates in the coaxial mode, the double line being the inner conductor and the waveguide walls being the outer conductor. Test results show a signal gain of greater than 10 dB within the instantaneous bandwidth from 3.1 Gc/s to 3.75 Gc/s.