The weapon closest to mass production uses a radio transponder in the handle that has to be activated by another radio device in a ring.

The readers are designed to pick up signals from radio transponders placed every 600 feet along the tracks.

The radio transponder continued to transmit signals for 64 seconds after the destruct command had been sent.

The system, with the aid of computers and radio transponders, is designed to route bar-coded baggage to automated carts that speed along tracks.

The main design change has been the placement of a tiny radio transponder inside the base of each key.

It features a device allowing drivers to pay the toll without slowing down, through a radio transponder on the dashboard.

Three, Kraj knew that I was here, which means they may have planted a directional radio transponder in me.

Oboe worked using two stations at different and well-separated locations in England to transmit a signal to a Mosquito Pathfinder bomber carrying a radio transponder.

Thirty seconds after liftoff the General Electric-Burroughs designed guidance system locked onto a radio transponder in the booster to guide the vehicle to orbit.

Soon after the introduction of radar, the radio transponder appeared.