Wideband simultaneous transmit and receive (STAR) subsystem

A self-interference-cancelling simultaneous transmit and receive (STAR) system, said system comprising:

• an antenna aperture;
• a transmitter circuit for transmitting signals over a frequency band through the antenna aperture, said transmitter circuit including a solid state power amplifier to minimize amplification of uncorrelated noise;
• a receiver circuit for receiving signals from the antenna aperture, said receiver circuit including a Gallium-Nitride differential low noise amplifier to maximize cancellation of the uncorrelated noise, where the receiver circuit uses the same frequency band as the transmitter circuit at the same time;
• a circulator for directing transmit signals from the transmitter circuit to the antenna aperture and received signals from the antenna aperture to the receiver circuit, where the circulator is an integrated nanowire magnetic circulator with high isolation to minimize leakage of the uncorrelated noise;
• and
• a canceller circuit including a plurality of tuners that operate on the transmit signals and synthesize a cancellation signal which is coupled into the receiver circuit, where the plurality of tuners include true time delay tuners which apply a true time delay to a leakage component and a reflection component of each of one or more digital transmit signals, and amplitude tuners which apply an amplitude scale factor to the leakage component and the reflection component of each of the digital transmit signals.

A method for cancelling interference in a simultaneous transmit and receive (STAR) system, said method comprising:

• providing one or more digital transmit signals to a transmitter circuit;
• creating, by the transmitter circuit, an analog transmit signal for transmission from the digital transmit signals;
• providing the analog transmit signal to a phased array antenna via a circulator;
• preparing, in a canceller circuit, a cancellation signal from the digital transmit signals, including applying a true time delay to a leakage component and a reflection component of each of the digital transmit signals, applying an amplitude scale factor to the leakage component and the reflection component of each of the digital transmit signals, and summing the leakage components and the reflection components after the true time delays and the amplitude scale factors have been applied;
• receiving a primary received signal from the antenna via the circulator;
• combining the cancellation signal with the primary received signal into a modified received signal, where the cancellation signal cancels leaked and reflected components of the analog RF transmit signal and correlated noise which are present in the primary received signal;
• and
• cancelling, in a receiver circuit, leaked and reflected components of uncorrelated noise from the modified received signal to create a final received signal.