A transponder is a wirelesscommunications, monitoring, or control device that picks up and automatically responds to an incoming signal. The term is a contraction of thewords transmitter and responder. Transponders can be eitherpassive or active.

Answered by pooja , an ibibo Master, at 10:33 AM on April 19, 2008

A transponder is a wireless communications, monitoring, or control device that picks up and automatically responds to an incoming signal. The term is a contraction of the words transmitter and responder. Transponders can be either passive or active.

Answered by satyakam , an ibibo Master, at 6:51 PM on April 11, 2008

In telecommunication, the term transponder (short-for Transmitter-responder and sometimes abbreviated to XPDR, XPNDR or TPDR) has the following meanings:
An automatic device that receives, amplifies, and retransmits a signal on a different frequency (see also broadcast translator).
An automatic device that transmits a predetermined message in response to a predefined received signal.
A receiver-transmitter that will generate a reply signal upon proper electronic interrogation..

Answered by ayisha , an ibibo Master, at 4:19 PM on April 11, 2008

In telecommunication, the term transponder (short-for Transmitter-responder and sometimes abbreviated to XPDR, XPNDR or TPDR) has the following meanings:

* An automatic device that receives, amplifies, and retransmits a signal on a different frequency (see also broadcast translator).
* An automatic device that transmits a predetermined message in response to a predefined received signal.
* A receiver-transmitter that will generate a reply signal upon proper electronic interrogation.
A communications satellite’s channels are called transponders, because each is a separate transceiver or repeater. With digital video data compression and multiplexing, several video and audio channels may travel through a single transponder on a single wideband carrier. Original analog video only has one channel per transponder, with subcarriers for audio and automatic transmission identification service ATIS. Non-multiplexed radio stations can also travel in single channel per carrier (SCPC) mode, with multiple carriers (analog or digital) per transponder. This allows each station to transmit directly to the satellite, rather than paying for a whole transponder, or using landlines to send it to an earth station for multiplexing with other stations.

Answered by Kaushal , an ibibo Advisor, at 4:08 PM on April 11, 2008

saurabh A transponder is a wireless communications, monitoring, or control device that picks up and automatically responds to an incoming signal

Answered by raj u , an ibibo Master, at 2:25 PM on April 11, 2008

A receiver/transmitter on a communications satellite. It receives a microwave signal from earth (uplink), amplifies it and retransmits it back to earth at a different frequency (downlink). A satellite has several transponders.

Answered by Nishis , an ibibo Master, at 12:30 PM on April 11, 2008

A transponder is a wirelesscommunications, monitoring, or control device that picks up and automatically responds to an incoming signal. The term is a contraction of thewords transmitter and responder. Transponders can be eitherpassive or active.

Answered by swadesh , an ibibo Specialist, at 12:19 PM on April 11, 2008

A transponder is a wirelesscommunications, monitoring, or control device that picks up and automatically responds to an incoming signal. The term is a contraction of thewords transmitter and responder. Transponders can be eitherpassive or active.
A passive transponder allows a computer or robot to identify an object. Magnetic labels, such as those on credit cards and store items, are commonexamples. A passive transponder must be used with an active sensor that decodes andtranscribes the data the transponder contains. The transponder unit can bephysically tiny, and its information can be sensed up to several feet away.

Simple active transponders are employed in location, identification, andnavigation systems for commercial and private aircraft. An example is an RFID (radio-frequency identification) devicethat transmits a coded signal when it receives a request from a monitoring or controlpoint. The transponder output signal is tracked, so the position of the transpondercan be constantly monitored. The input (receiver) and output (transmitter) frequencies are preassigned. Transpondersof this type can operate over distances of thousands of miles.

Sophisticated active transponders are used in communications satellites and on board space vehicles. They receive incoming signals over a range, or band, of frequencies, and retransmit thesignals on a different band at the same time. The device is similar to a repeater of the sort used in land-based cellulartelephone networks. The incoming signal, usually originating from a point on theearth's surface, is called the uplink. The outgoing signal, usually sent toa point or region on the surface, is the downlink. These transponderssometimes operate on an interplanetary scale.

Answered by Sudipta Deb , an ibibo Specialist, at 10:11 AM on April 11, 2008

Well first of all it is 'TRANSPONDER' not transpoder. It is a wireless communications device usually attached to a satellite. A transponder receives and transmits radio signals at a prescribed frequency range. After receiving the signal a transponder will at the same time broadcast the signal at a different frequency. The term is a combination of the words transmitter and responder. Transponders are used in satellite communications and in location, identification and navigation systems.
A passive transponder allows a computer or robot to identify an object. Magnetic labels, such as those on credit cards and store items, are commonexamples. A passive transponder must be used with an active sensor that decodes andtranscribes the data the transponder contains. The transponder unit can bephysically tiny, and its information can be sensed up to several feet away.

Answered by Hemant Kumar , an ibibo Master, at 10:04 AM on April 11, 2008