SPY-1D gave Flights I, II, and IIA a passive electronically scanned array (PESA) radar, even as successive computer and electronics upgrades improved the system. PESA electronically steers the beam while connecting antenna elements to a shared transmitter and receiver. This was a mature technology by the time the first Burkes entered service. Flight III's active electronically scanned array (AESA) represents a further change in radar architecture. Each element has a small computer-controlled transmitter-receiver module, increasing potential transmitting and receiving capability while demanding more computing and electrical power.
Notable Point · 23:23-28:43
SPY-1D and the transition from PESA to AESA radar
The PESA/AESA comparison explains what changed in radar architecture beyond ordinary Burke electronics upgrades.