Super heterodyned power detector with enhanced linearity for use in power leveling loops

摘要

The present invention provides an improved power detector and more particularly a power leveling loop with a superheterodyned adjustable gain power detector. In one preferred embodiment, the adjustable gain power leveling detector receives an output signal from a directional coupler. According to the present invention, the leveling detector includes means for producing a signal whose amplitude is proportional to the amplitude of the output signal from the directional coupler and whose frequency is equal to a fixed intermodulation IF frequency, a power detector for providing a stable DC output voltage signal for an input of a single power at the IF frequency; and a leveling loop for maintaining the power detector DC voltage signal substantially constant.