Abstract: A system for transmitting and receiving electromagnetic waves simultaneously. A portion of a signal to be transmitted through a transmitting antenna element is diverted from a transmit signal path, processed by an adjustable filter, and coupled into receive signal path. The adjustable filter is adjusted to approximate the channel that the leakage signals go through to get from the transmitter to the receiver so that the signal coupled into the receiving path through the filter partially cancels the parasitic leakage from the transmit signal path to the receive signal path.

Abstract: Systems and methods described herein are directed towards an active electronically scanned array (AESA) that can perform both frequency division duplexing (FDD) operations and time division duplexing (TDD) operations. The AESA includes a switch network having one or more switching stages coupled between a transceiver and one or more array elements to switch the AESA between FDD operation and TDD operations, modify a function of one or more of the array elements in the AESA and/or swap portions of the AESA between different functions. The switch network can be disposed in a feed portion of the AESA. Thus, functions of each of the array elements or subarrays of multiple array elements in the AESA can be modified at a feed portion of the AESA. The array elements can be configured for TDD operations and FDD operations and can be configured as a transmit elements, receive elements or isolation elements.

Abstract: Method and apparatus for leakage signal cancellation in a simultaneous transmit and receive RF system includes: generating a digital transmit signal for transmission from the system; receiving a receive signal produced by reflection of the transmit signal from an object or generated by a second RF system; adaptively filtering the transmit signal by an adaptive finite input response (FIR) filter; calculating filter coefficients for the adaptive FIR filter in real-time at a different sampling rate; adaptively inputting the calculated filter coefficients to the adaptive FIR filter to generate a cancellation signal in real-time; and applying the cancellation signal to the receive signal to cancel leakage in the receive signal to generate an optimum receive signal.

Abstract: A system for transmitting and receiving electromagnetic waves simultaneously. A portion of a signal to be transmitted through a transmitting antenna element is diverted from a transmit signal path, processed by an adjustable filter, and coupled into receive signal path. The adjustable filter is adjusted to approximate the channel that the leakage signals go through to get from the transmitter to the receiver so that the signal coupled into the receiving path through the filter partially cancels the parasitic leakage from the transmit signal path to the receive signal path.

Abstract: Systems and methods described herein are directed towards an active electronically scanned array (AESA) that can perform both frequency division duplexing (FDD) operations and time division duplexing (TDD) operations. The AESA includes a switch network having one or more switching stages coupled between a transceiver and one or more array elements to switch the AESA between FDD operation and TDD operations, modify a function of one or more of the array elements in the AESA and/or swap portions of the AESA between different functions. The switch network can be disposed in a feed portion of the AESA. Thus, functions of each of the array elements or subarrays of multiple array elements in the AESA can be modified at a feed portion of the AESA. The array elements can be configured for TDD operations and FDD operations and can be configured as a transmit elements, receive elements or isolation elements.

Abstract: Method and apparatus for leakage signal cancellation in a simultaneous transmit and receive RF system includes: generating a digital transmit signal for transmission from the system; receiving a receive signal produced by reflection of the transmit signal from an object or generated by a second RF system; adaptively filtering the transmit signal by an adaptive finite input response (FIR) filter; calculating filter coefficients for the adaptive FIR filter in real-time at a different sampling rate; adaptively inputting the calculated filter coefficients to the adaptive FIR filter to generate a cancellation signal in real-time; and applying the cancellation signal to the receive signal to cancel leakage in the receive signal to generate an optimum receive signal.