Transmitter: Difference between revisions

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== Transmitter ==
= Transmitter =


A '''transmitter''' is an electronic device that produces radio waves with an antenna. The transmitter itself generates a radio frequency alternating current, which is applied to the antenna. When excited by this alternating current, the antenna radiates radio waves. Transmitters are necessary components of all electronic devices that communicate by radio, such as [[radio]] and [[television]] broadcasting stations, [[cellular phones]], [[wireless computer networks]], [[Bluetooth]]-enabled devices, [[garage door openers]], and [[two-way radios]].
A '''transmitter''' is an electronic device that produces radio waves with an antenna. The transmitter itself generates a radio frequency alternating current, which is applied to the antenna. When excited by this alternating current, the antenna radiates radio waves. Transmitters are necessary components of all electronic devices that communicate by radio, such as [[radio]] and [[television]] broadcasting stations, [[cellular phone]]s, [[walkie-talkie]]s, [[wireless network]]s, [[Bluetooth]]-enabled devices, [[garage door opener]]s, [[two-way radio]]s in aircraft, ships, [[spacecraft]], [[radar]] sets, and [[navigational beacon]]s.


== History ==
== Components ==


The development of the transmitter began with the discovery of radio waves by [[Heinrich Hertz]] in the late 19th century. Hertz's experiments in 1887 demonstrated the existence of electromagnetic waves, which were predicted by [[James Clerk Maxwell]]. The first practical radio transmitters were developed by [[Guglielmo Marconi]] in the early 20th century, using spark-gap technology. These early transmitters were capable of sending Morse code signals over long distances.
A typical transmitter consists of several key components:
 
=== Power Supply ===
The power supply provides the necessary electrical power to operate the transmitter.
 
=== Oscillator ===
The oscillator creates the alternating current at the frequency on which the transmitter will transmit. This is the carrier wave.
 
=== Modulator ===
The modulator adds the information to be transmitted to the carrier wave. This can be done by varying the amplitude, frequency, or phase of the carrier wave.
 
=== Amplifier ===
The amplifier increases the power of the signal to a level suitable for transmission.


In the 1920s, the invention of the [[vacuum tube]] allowed for the development of continuous wave transmitters, which could transmit audio signals. This led to the birth of [[AM radio]] broadcasting. The invention of the [[frequency modulation|FM]] transmitter by [[Edwin Armstrong]] in the 1930s improved the quality of radio broadcasts by reducing static and interference.
=== Antenna ===
The antenna converts the amplified signal into radio waves.


== Types of Transmitters ==
== Types of Transmitters ==


=== Radio Transmitters ===
=== Radio Transmitters ===
Radio transmitters are used in [[broadcasting]] to send audio signals to a wide audience. They can be classified into AM and FM transmitters, based on the modulation technique used.
[[File:WDET-FM_transmitter.png|thumb|right|A radio transmitter for WDET-FM]]
Radio transmitters are used in [[broadcasting]] to send audio signals to radios. They can be [[AM]] or [[FM]] transmitters, depending on the modulation technique used.


=== Television Transmitters ===
=== Television Transmitters ===
Television transmitters send both audio and video signals. They use a combination of amplitude modulation for video and frequency modulation for audio.
Television transmitters send both audio and video signals to television receivers. They use [[frequency modulation]] for audio and [[amplitude modulation]] for video.
 
=== Communication Transmitters ===
[[File:CB-Funkgerät_im_LKW.JPG|thumb|left|A CB radio transmitter in a truck]]
These transmitters are used in various communication devices such as [[cell phones]], [[walkie-talkies]], and [[CB radios]].
 
=== Radar Transmitters ===
Radar transmitters send out pulses of radio waves and receive the echoes to determine the location and speed of objects.


=== Microwave Transmitters ===
=== Microwave Transmitters ===
Microwave transmitters are used for point-to-point communication links, such as [[satellite communication]] and [[radar]].
Microwave transmitters are used for point-to-point communication links and in [[satellite communication]].
 
== Signal Processing ==
[[File:Signal_processing_system.png|thumb|right|Signal processing system]]
Signal processing in transmitters involves the manipulation of the signal to improve transmission quality and efficiency. This includes filtering, modulation, and amplification.
 
== Historical Transmitters ==


=== Mobile and Wireless Transmitters ===
=== Vacuum Tube Transmitters ===
These transmitters are used in [[cellular networks]], [[Wi-Fi]], and [[Bluetooth]] devices. They operate at various frequencies and power levels depending on the application.
[[File:Transmisor_de_bulbos_AM_Elcom_Bauer_701_B_XEQK.jpg|thumb|left|A vacuum tube AM transmitter]]
Early transmitters used vacuum tubes to generate and amplify signals. These were large and required significant power.


== Components of a Transmitter ==
=== Solid State Transmitters ===
Modern transmitters use solid-state devices such as transistors, which are more efficient and compact.


A typical transmitter consists of several key components:
== Modern Transmitters ==


* '''Oscillator''': Generates the radio frequency signal.
=== Digital Transmitters ===
* '''Modulator''': Imposes the information signal onto the carrier wave.
Digital transmitters use digital modulation techniques to transmit data. They are used in modern [[digital television]] and [[digital radio]] broadcasting.
* '''Amplifier''': Increases the power of the modulated signal.
* '''Antenna''': Radiates the signal into space.


== Related Pages ==
=== Software-Defined Radio ===
Software-defined radio (SDR) transmitters use software to perform signal processing tasks that were traditionally done by hardware.


* [[Antenna (radio)]]
== Applications ==
* [[Modulation]]
* [[Radio broadcasting]]
* [[Television broadcasting]]
* [[Wireless communication]]


== References ==
=== Broadcasting ===
Transmitters are used in radio and television broadcasting to send audio and video signals to the public.


* "Radio Transmitters." Encyclopedia of Radio, edited by Christopher H. Sterling, Routledge, 2004.
=== Telecommunications ===
* "The Invention of Radio." IEEE Global History Network, IEEE, 2010.
[[File:Cordless_phone_icon.svg|thumb|right|Cordless phone]]
* "Wireless Communication: Principles and Practice." Theodore S. Rappaport, Prentice Hall, 2002.
Transmitters are essential in telecommunications for sending voice and data over long distances.


== Gallery ==
=== Navigation ===
Transmitters are used in navigation systems such as [[GPS]] to send signals to receivers.


<gallery>
== Related Pages ==
File:WDET-FM_transmitter.png|WDET-FM transmitter
* [[Antenna (radio)]]
File:Signal_processing_system.png|Signal processing system
* [[Modulation]]
File:Transmisor_de_bulbos_AM_Elcom_Bauer_701_B_XEQK.jpg|AM Elcom Bauer transmitter
* [[Radio wave]]
File:KWNR_Continental_816R-5B_SN_247.jpg|KWNR Continental transmitter
* [[Broadcasting]]
File:Icom_IC-746PRO.jpg|Icom IC-746PRO
* [[Telecommunication]]
radio in a truck
File:HA0478-006_(6011470974).jpg|Historical transmitter
File:Cordless_phone_icon.svg|Cordless phone
File:Garage-door-opener-remote-control.png|Garage door opener remote
File:Wireless_network.jpg|Wireless network
File:Plantronics_Voyager_Legend.JPG|Bluetooth headset
File:Dipole_xmting_antenna_animation_4_408x318x150ms.gif|Dipole transmitting antenna
File:Heinrich_Hertz_discovering_radio_waves.png|Heinrich Hertz discovering radio waves
File:Marconi_1897_spark_gap_transmitter.jpg|Marconi's spark gap transmitter
File:Powerful_spark_gap_transmitter.png|Powerful spark gap transmitter
File:Poulsen_arc_1MW_transmitter.jpg|Poulsen arc transmitter
File:Alexanderson_Alternator.jpg|Alexanderson alternator
File:First_vacuum_tube_AM_radio_transmitter.jpg|First vacuum tube AM radio transmitter
File:Blythe_House_Science_Museum_stores_tour_99.JPG|Blythe House Science Museum
File:Armstrong_prototype_FM_transmitter_1935.jpg|Armstrong's FM transmitter prototype
File:Magnetron_radar_assembly_1947.jpg|Magnetron radar assembly
</gallery>


[[Category:Radio technology]]
[[Category:Radio technology]]
<gallery>
[[Category:Broadcast engineering]]
File:WDET-FM_transmitter.png|Transmitter
[[Category:Telecommunications equipment]]
File:Transmisor_de_bulbos_AM_Elcom_Bauer_701_B_XEQK.jpg|Transmitter
File:KWNR_Continental_816R-5B_SN_247.jpg|Transmitter
File:Icom_IC-746PRO.jpg|Transmitter
File:CB-Funkgerät_im_LKW.JPG|Transmitter
File:HA0478-006_(6011470974).jpg|Transmitter
File:Cordless_phone_icon.svg|Transmitter
File:Garage-door-opener-remote-control.png|Transmitter
File:Wireless_network.jpg|Transmitter
File:Plantronics_Voyager_Legend.JPG|Transmitter
File:Dipole_xmting_antenna_animation_4_408x318x150ms.gif|Transmitter
File:Heinrich_Hertz_discovering_radio_waves.png|Transmitter
</gallery>

Latest revision as of 14:13, 21 February 2025

Transmitter[edit]

A transmitter is an electronic device that produces radio waves with an antenna. The transmitter itself generates a radio frequency alternating current, which is applied to the antenna. When excited by this alternating current, the antenna radiates radio waves. Transmitters are necessary components of all electronic devices that communicate by radio, such as radio and television broadcasting stations, cellular phones, walkie-talkies, wireless networks, Bluetooth-enabled devices, garage door openers, two-way radios in aircraft, ships, spacecraft, radar sets, and navigational beacons.

Components[edit]

A typical transmitter consists of several key components:

Power Supply[edit]

The power supply provides the necessary electrical power to operate the transmitter.

Oscillator[edit]

The oscillator creates the alternating current at the frequency on which the transmitter will transmit. This is the carrier wave.

Modulator[edit]

The modulator adds the information to be transmitted to the carrier wave. This can be done by varying the amplitude, frequency, or phase of the carrier wave.

Amplifier[edit]

The amplifier increases the power of the signal to a level suitable for transmission.

Antenna[edit]

The antenna converts the amplified signal into radio waves.

Types of Transmitters[edit]

Radio Transmitters[edit]

A radio transmitter for WDET-FM

Radio transmitters are used in broadcasting to send audio signals to radios. They can be AM or FM transmitters, depending on the modulation technique used.

Television Transmitters[edit]

Television transmitters send both audio and video signals to television receivers. They use frequency modulation for audio and amplitude modulation for video.

Communication Transmitters[edit]

A CB radio transmitter in a truck

These transmitters are used in various communication devices such as cell phones, walkie-talkies, and CB radios.

Radar Transmitters[edit]

Radar transmitters send out pulses of radio waves and receive the echoes to determine the location and speed of objects.

Microwave Transmitters[edit]

Microwave transmitters are used for point-to-point communication links and in satellite communication.

Signal Processing[edit]

Signal processing system

Signal processing in transmitters involves the manipulation of the signal to improve transmission quality and efficiency. This includes filtering, modulation, and amplification.

Historical Transmitters[edit]

Vacuum Tube Transmitters[edit]

A vacuum tube AM transmitter

Early transmitters used vacuum tubes to generate and amplify signals. These were large and required significant power.

Solid State Transmitters[edit]

Modern transmitters use solid-state devices such as transistors, which are more efficient and compact.

Modern Transmitters[edit]

Digital Transmitters[edit]

Digital transmitters use digital modulation techniques to transmit data. They are used in modern digital television and digital radio broadcasting.

Software-Defined Radio[edit]

Software-defined radio (SDR) transmitters use software to perform signal processing tasks that were traditionally done by hardware.

Applications[edit]

Broadcasting[edit]

Transmitters are used in radio and television broadcasting to send audio and video signals to the public.

Telecommunications[edit]

Cordless phone

Transmitters are essential in telecommunications for sending voice and data over long distances.

Navigation[edit]

Transmitters are used in navigation systems such as GPS to send signals to receivers.

Related Pages[edit]