Description of the radar set, tactical-technical characteristics
|frequency:||1 280 … 1 350 MHz|
|pulse repetition time (PRT):||2 858 µs|
|pulse repetition frequency (PRF):||350 Hz|
|pulsewidth (τ):||2 µs|
|peak power:||2 … 2.5 MW|
|average power:||4.35 … 6 KW|
|instrumented range:||231 NM (≙ 428 km)|
|range resolution:||1000 Yard|
|hits per scan:|
|antenna rotation:||3.3, 5 or 10 rpm|
AN/FPS-20 was a widely used L-Band early warning and ground-controlled interception radar system, developed by Bendix orporation. The radar family started with the AN/FPS-3 in 1950, used a transmitter with two magnetrons.
The production of AN/FPS-20 began in 1956 with a dual-channel liquid-cooled klystron transmitter. Each receiver used the “Dicke Fix”- processing. The antenna was equipped with a polarizer and could work alternating in circular or linear horizontal polarization.
Later updates (including anti-jamming opportunities mostly) led to the designations AN/FPS-64, AN/FPS-65, AN/FPS-66, AN/FPS-67, AN/FPS-91, AN/FPS-93, AN/FPS-100, AN/FPS-113 and AN/GPS-4. The Canadian vwesion got the designator AN/FPS-508.
|Original System||+ Upgrade||= New System|
|AN/FPS-20||+ AN/GPA-102||= AN/FPS-64|
|AN/FPS-20||+ AN/GPA-103||= AN/FPS-65|
|AN/FPS-20A||+ AN/GPA-102||= AN/FPS-66|
|AN/FPS-20A||+ AN/GPA-103||= AN/FPS-67|
|AN/FPS-20||+ OA-7091/FPS||= AN/FPS-100|
Similar upgrades using a Canadian OA-4831 system produced the AN/FPS-87 and AN/FPS-87A. A more major update was the adding of a new antenna from Raytheon, the Diplex Gating Unit (DGU), a bandpass filter and other modifications, to produce the AN/FPS-91 and 91A. The similar MK-748 applied to the -60 series resulted in the AN/FPS-64A, -65A, -66A and -67A. The radar AN/FPS-66A was also used by the FAA as en-route radar and got the designator ARSR-66. Canadian AN/FPS-87s were also converted, becoming AN/FPS-93 and 93A.