Method and apparatus for a full-duplex electromagnetic transceiver

Abstract

A cancellation circuit removes interfering signals from desired signals in electrical systems having antennas or other electromagnetic pickup systems. The cancellation circuit provides amplitude adjustment and phase adjustment to electrical signals induced in an electrical system by received electromagnetic signals. The cancellation circuit may be adapted to process received electromagnetic waves having multiple frequencies. Phase adjustment compensates for electrical path-length differences between signals resulting from propagation delays, circuit delays, and multipath. The amplitude-adjusted and phase-adjusted signals are combined to cancel the effects of electromagnetic interference. In an electromagnetic receiver, a plurality of receiver elements provide the cancellation circuit with different complex proportions of desired and interfering signals to enable removal of the interfering signals. An electromagnetic-wave transmitter having multiple transmitter elements is provided with a cancellation circuit for canceling electromagnetic signals in at least one predetermined region of space. A compensation circuit enables the cancellation circuit to compensate for frequency-dependent phase and amplitude differences in received signals and/or transmitted electromagnetic waves having multiple frequencies and/or broadband characteristics.