Antenna element self-test and monitoring

An apparatus system comprising:

• a phased array antenna comprising an array of antenna elements, the array of antenna elements forming a plurality of antenna element pairs, each antenna element pair of the plurality of antenna element pairs including a first antenna element and a second antenna element;
• a plurality of transmitter circuits, each transmitter circuits of the plurality of transmitter circuits connected to a different corresponding one of the antenna elements within the array of antenna elements;
• for each transmitter circuit among the plurality of transmitter circuits, a bidirectional coupler connected between that transmitter circuit and the antenna element to which that transmitter circuit is connected;
• a detector system for measuring a signal characteristic;
• a switching system for selectively connecting signals from the bidirectional couplers for the plurality of transmitter circuits to the detector system;
• and
• a processor system programmed to use the switching system and the detector system to perform the operations of:
• for each antenna element pair of the plurality of antenna element pairs, performing a first cross element gain measurement from the first antenna element to the second antenna element of that antenna element pair;
• and
• determining whether there is a problem associated with the phased array antenna by examining the first cross element gain measurements for the plurality of antenna element pairs.