transponder

American  

[tran-spon-der] / trænˈspɒn dər /

Or transpondor

noun

1. a radio, radar, or sonar transceiver that automatically transmits a signal upon reception of a designated incoming signal.

---

transponder British  

/ trænˈspɒndə /

noun

1. a type of radio or radar transmitter-receiver that transmits signals automatically when it receives predetermined signals

2. the receiver and transmitter in a communications or broadcast satellite, relaying received signals back to earth

---

transponder Scientific  

/ trăn-spŏn′dər /

1. A radio or radar transmitter and receiver that responds to an incoming signal either by broadcasting its own predetermined signal (as in aircraft identification systems) or by relaying the incoming signal at a different frequency (as in satellite communications).

---

Etymology

Origin of transponder

First recorded in 1940–45; trans(mitter) + (res)ponder

Example Sentences

China and Russia show little effort to disguise the trade, with tankers carrying the sanctioned cargoes continuing to broadcast their positions through so-called AIS transponder signals.

From The Wall Street Journal

Russia will probably find ways around restrictions by setting up new supply chains to handle energy deals, and redoubling efforts to disguise where cargoes have come from using ship-to-ship transfers or manipulating ships’ transponders.

From The Wall Street Journal

Collision-avoidance systems on commercial jets typically use a mix of transponders and other sensors, but not radar.

From The Wall Street Journal

The Los Angeles County Metropolitan Transportation Authority said it doesn’t anticipate a significant uptick in the number of FasTrak transponders being issued as a consequence of the decal program’s end.

From Los Angeles Times

Estonian media are reporting that in the latest incident the Russian jets had their transponders switched off.

From BBC