AN/TPX-19 to TPX-23

The AN/TPX-19 to AN/TPX-23 series comprises secondary surveillance radar (SSR) identification interrogators, operating in the L-band (990-1040 MHz) according to IEEE designation, or D-band by NATO designation. These systems were designed for the Identification Friend or Foe (IFF) Mark X SIF standard, compatible with the AN/AFX-6 airborne transponder. The variations in designation reflect adaptations for integration with different primary radar systems, primarily differing in antenna configuration. For instance, the AN/TPX-19 was integrated into the AN/TPS-1D and SCR-584 radars, with its IFF antenna forming part of the primary radiator and transmit/receive feed via coaxial cable. The AN/TPX-20 was deployed within U.S. Nike Hercules air defense missile system sites, while the AN/TPX-21 was used with the T-38 Skysweeper artillery radar. Although theoretically capable of multiple transmission frequencies for backward compatibility, only frequency No. 3 (nominally 1030 MHz) was utilized due to standardization of the interrogation protocol.

radartutorial.eu: https://www.radartutorial.eu/19.kartei/14.ssr/karte030.en.html