Low-distortion modulation of infrared and submillimetre waves with crossed reverse-biased junction diodes

Modulation of radiation using free-carrier absorption in a pair of crossed reverse-biased junction diodes is discussed. The condition for negligible distortion is examined, and it is shown that a single unit may be worked to yield 25% modulation with distortion within 1% up to a frequency of 1 Gc/s and efficiency somewhat higher than that of a single diode.