Simultaneous transmit and receive through active cancellation

A simultaneous transmit and receive (STAR) system, comprising:

• a plurality of radiating elements configured as part of an antenna array, the antenna array configured for transmitting signals and for receiving signals;
• and
• a plurality of antenna transmit/receive (T/R) elements, each respective T/R element being in operable communication with a respective radiating element, each respective T/R element comprising a first transmit channel, a second transmit channel independent of the first transmit channel, a receive channel, and a directional coupler, wherein, for each respective T/R element:
• the first transmit channel has an input configured to receive a signal to be transmitted and an output configured to operably couple the signal to be transmitted to the respective radiating element;
• the second transmit channel has an input configured to receive an active cancellation signal and an output configured to operably couple the active cancellation signal to the directional coupler;
• the directional coupler comprises a radiofrequency (RF) input in operable communication with the antenna array to receive a signal received by the antenna array, an RF output configured to couple the received signal to an input of the receive channel, and a coupled input in operable communication with the output of the second transmit channel;
• and
• the active cancellation signal is configured to cancel at least some coupling effects that arise on an input to the receive channel, the coupling effects arising from operation of at least a portion of the plurality of T/R elements.

A method for simultaneous transmit and receive (STAR) operation, comprising:

• operating a system comprising (i) a plurality of radiating elements configured as part of an antenna array, the antenna array configured for transmitting signals and for receiving signals, and (ii) a plurality of antenna transmit/receive (T/R) elements coupled to be in operable communication with the plurality of radiating elements, wherein:
• each respective T/R element is in operable communication with a respective radiating element;
• each respective T/R element comprises a first transmit channel, a receive channel, a switch, and a directional coupler;
• and
• for each respective T/R element:
• the directional coupler comprises a radiofrequency (RF) input in operable communication with the antenna array to receive signals received by the antenna array, an RF output configured to couple the received signals to an input of the receive channel, and a coupled input in operable communication with the switch;
• and
• the switch comprises an input in operable communication with an output of the first transmit channel, a transmit pole in operable communication with the respective radiating element, and a feedback pole in operable communication with the coupled input of the directional coupler;
• setting, for at least a first T/R element of the plurality of T/R elements, the switch of the first T/R element to the transmit pole to cause an output of the first transmit channel of the first T/R element to be provided to the respective radiating element for the first T/R element;
• setting, for at least a second of the plurality of T/R elements, the switch of the second T/R element to the feedback pole to cause an output of the first transmit channel of the second T/R element to be provided to the coupled input of the directional coupler;
• providing a transmit signal to an input of the first transmit channel of the first T/R element, wherein the first T/R element provides the transmit signal to its respective radiating element to be radiated into a target area;
• receiving, at the antenna array, a received signal that is provided to an input of the receive channel of the second T/R element;
• and
• providing an active cancellation signal to an input of the first transmit channel of the second T/R element, wherein the directional coupler of the second T/R element is configured to provide the active cancellation signal to the input of the receive channel of the second T/R element, wherein the active cancellation signal is configured to cancel at least some coupling effects that arise on the input to the receive channel of the second T/R element, the coupling effects arising from providing the transmit signal to the first T/R element, and wherein the active cancellation signal is configured to enable the input to the receive channel to be as close a match as possible to the received signal.