Transmitter signal cancellation in phased array receivers

A method employing an array of antenna elements and a plurality of transceivers, each including (1) a transmitter chain;

• (2) a receiver chain;
• and (3) a duplexer having a transmit input electrically connected to the transmitter chain, a receive output electrically connected to the receiver chain, and a duplexed port electrically connected to a corresponding different antenna element within the array of antenna elements, said method comprising:
• identifying among the plurality of transceivers a first subset of transceivers and a second subset of transceivers such that together the first and second subsets of transceivers constitute all of the transceivers among the plurality of transceivers;
• for each transceiver within the first subset of transceivers, but not for the transceivers within the second subset of transceivers, introducing a Φ degree phase shift between the duplexed port of the duplexer within that transceiver and the antenna element to which the duplexed port of that duplexer is electrically connected, wherein Φ=−(2n+1)90°, and wherein n is an integer.

A phased array system comprising:

• an array of antenna elements,
• a first transceiver subset that comprises at least one transceiver, and
• a second transceiver subset that comprises at least one transceiver,
• wherein each of the transceivers comprises
• a transceiver input,
• a transmitter chain that receives a transmit signal via the transceiver input,
• a transceiver output;
• a receiver chain that carries a residual transmit signal and a receive signal to the transceiver output,
• a duplexer having a transmit-input electrically coupled to the transceiver input via the transmitter chain, a receive-output electrically coupled to the transceiver output to the receiver chain, and a duplexed port electrically connected to a corresponding antenna element within the array, and
• wherein a residual path is defined between the transceiver input and the transceiver output;
• wherein for each transceiver in the first subset there exists a transceiver in the second subset such that the residual paths of the first and second transceivers differ by 180° in phase at an operating frequency of the phased array system.