Patent ID: 6066992
Filing Date: 2000-05-23
Classification: H01P

Abstract:
A variable attenuator comprising:a circulator having an input port for receiving a signal, an intermediate port, an output port for outputting an attenuated signal, and means for routing of signals received at said input port to said intermediate port, and signals received at said intermediate port to said output port;a section of transmission line comprising a waveguide having a first end coupled to the intermediate port and a second end coupled to a terminating load, said transmission line transmitting signals routed to said intermediate port toward the second end of the transmission; andat least one variable tuning element coupled to said transmission line, said tuning element comprising a tuning element variably extendable within said waveguide for reflecting a predetermined amount of signal passing through the transmission line back toward the first end, wherein the reflected portion of the received signal is routed by the circulator to said output port, and the remaining portion of the received signal is absorbed by the terminating load.