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{{Short description|Device that both transmits and receives}}
{{inline|date=August 2020}}

In [[radio communication]], a '''transceiver''' is an electronic device which is a combination of a radio [[transmitter|''trans''mitter]] and a [[Radio receiver|re''ceiver'']], hence the name. It can both transmit and receive [[radio wave]]s using an [[antenna (radio)|antenna]], for communication purposes.  These two related functions are often combined in a single device to reduce manufacturing costs.  The term is also used for other devices which can both transmit and receive through a [[communications channel]], such as ''optical transceivers'' which transmit and receive light in [[optical fiber]] systems, and ''bus transceivers'' which transmit and receive [[digital data]] in computer [[data bus]]es.

Radio transceivers are widely used in [[wireless devices]].  One large use is in [[two-way radio]]s, which are [[Audio signal|audio]] transceivers used for bidirectional person-to-person voice communication.  Examples are [[cell phone]]s, which transmit and receive the two sides of a phone conversation using radio waves to a [[cell tower]], [[cordless phone]]s in which both the phone handset and the base station have transceivers to communicate both sides of the conversation, and [[land mobile radio system]]s like [[walkie-talkie]]s and [[CB radio]]s.  Another large use is in [[wireless modem]]s in mobile networked computer devices such [[laptop]]s, pads, and cellphones, which both transmit digital data to and receive data from a [[wireless router]].  Aircraft carry automated [[microwave]] transceivers called [[aircraft transponder|transponders]] which, when they are triggered by microwaves from an [[airport surveillance radar|air traffic control radar]], transmit a coded signal back to the radar to identify the aircraft.  Satellite transponders in [[communication satellite]]s receive digital telecommunication data from a [[satellite ground station]], and retransmit it to another ground station.

==History==
[[File:Icom.png|thumb|A modern [[High frequency|HF]] transceiver with a [[spectrum analyzer]] and [[Digital signal processing|DSP]] capabilities]]
The transceiver first appeared in the 1920s.{{cn|date=March 2024}} Before then, receivers and transmitters were manufactured separately and devices that wanted to receive and transmit data required both components. Almost all amateur radio equipment today{{when?|date=March 2024}} uses transceivers, but there is an active market for pure radio receivers, which are mainly used by [[shortwave listening]] operators.{{cn|date=March 2024}}

===Analog===
Analog transceivers use [[frequency modulation]] to send and receive data. Although this technique limits the complexity of the data that can be broadcast, analog transceivers operate very reliably and are used in many emergency communication systems. They are also cheaper than digital transceivers, which makes them popular with the [[Citizens band radio|CB]] and [[HAM radio]] communities.

===Digital===
Digital transceivers send and receive [[binary data]] over radio waves. This allows more types of data to be broadcast, including video and encrypted communication, which is commonly used by police and fire departments. Digital transmissions tend to be clearer and more detailed than their analog counterparts. Many modern wireless devices operate on digital transmissions.

==Usage==
===Telephony===
[[File:PXE.jpg|thumb|A decapped integrated circuit of a transceiver used in handheld communication devices and radio equipment as a modem extension. On-die passfilters are visible.]]
<!-- This section is linked from [[Headphones]]. -->
In a wired [[telephone]], the handset contains the transmitter (for speaking) and receiver (for listening).  Despite being able to transmit and receive data, the whole unit is colloquially referred to as a "receiver".  On a [[mobile telephone]] or other [[radiotelephone]], the entire unit is a transceiver for both audio and radio.

A [[cordless telephone]] uses an audio and radio transceiver for the handset, and a radio transceiver for the [[base station]]. If a [[speakerphone]] is included in a wired telephone base or in a cordless base station, the base also becomes an audio transceiver.

A [[modem]] is similar to a transceiver in that it sends and receives a signal, but a modem uses modulation and demodulation. It modulates the signal being transmitted and demodulates the signal being received.

===Ethernet===
[[File:Ethernet-media-converter-transceiver-0a.jpg|thumb|[[100BASE-TX]] connected to a [[100BASE-FX]] transceiver]]
Transceivers are called [[Transmission medium|Medium]] Attachment Units ([[Medium Attachment Unit|MAU]]s) in [[IEEE 802.3]] documents and were widely used in [[10BASE2]] and [[10BASE5]] [[Ethernet]] networks. [[Fiber-optic]] [[gigabit Ethernet|gigabit]], [[10 Gigabit Ethernet]], [[40 Gigabit Ethernet]], and [[100 Gigabit Ethernet]] utilize [[GBIC]], [[SFP transceiver|SFP]], [[SFP+]], [[QSFP]], [[XFP]], [[XAUI]], [[CXP_(connector)|CXP]], and [[C form-factor pluggable|CFP]] transceiver systems.

==Regulation==
{{See also|Federal Communications Commission}}
Because transceivers are capable of broadcasting information over airwaves, they are required to adhere to various regulations.  In the United States, the [[Federal Communications Commission]] oversees their use.  Transceivers must meet certain standards and capabilities depending on their intended use, and manufacturers must comply with these requirements.  However, transceivers can be modified by users to violate FCC regulations.  For instance, they might be used to broadcast on a frequency or channel that they should not have access to.  For this reason, the FCC monitors not only the production but also the use of these devices.

==See also==
{{Portal|Electronics}}
* [[Two-way radio]]
* [[4P4C]], [[de facto standard]] [[Electrical connector|connector]] for telephone handsets
* [[Duplex (telecommunications)|Duplex]], two-way communications capability
* [[Radar beacon]]
* [[Transmitter]]
* [[Radio transmitter design]]
* [[Radio receiver]]
* [[Radio receiver design]]
* [[Transponder]]

==References==
{{reflist}}
* Rutledge, D. (1999). ''The electronics of radio''. Cambridge [England]; New York: Cambridge University Press.
* Reinhart, R. C. K. (2004). ''Reconfigurable transceiver and software-defined radio architecture and technology evaluated for NASA space communications''. <nowiki>https://ntrs.nasa.gov/search.jsp?R=20050215177</nowiki>
* ''Govinfo''. (n.d.). Retrieved February 29, 2020, from <nowiki>https://www.govinfo.gov/app/details/CFR-2010-title47-vol1/CFR-2010-title47-vol1-sec2-926</nowiki>
* Haring, K. (2007). ''Ham radio's technical culture'' (Inside technology). Cambridge, Mass.: MIT Press.
* {{FS1037C MS188}}

==External links ==
{{Wiktionary|transceiver|handset}}
{{Commons category multi|Transceivers|Radio transceivers}}
* ''{{US patent|0716136}}'', [[John Stone Stone]], "Apparatus for simultaneously transmitting and receiving space telegraph signals"
* [http://hamradio.co.in/tcvr/index.php 7 MHz SSB transceiver]

{{Authority control}}

[[Category:Networking hardware]]
[[Category:Radio electronics]]
[[Category:Telecommunications equipment]]