Home arrow Relays arrow What is a Repeater?

arrow left

arrow right

What is a Repeater?

Author: Apogeeweb Date: 12 May 2022  1962

redstone repeater


Ⅰ What is a Repeater?

Ⅱ Types of Repeater

2.1 Telephone Repeater

2.2 Optical Communications Repeater

2.3 Radio Repeater

Ⅲ How Does a Repeater Work?

Ⅳ Features of Repeater

Ⅴ Advantages of Repeaters

Ⅵ Disadvantages of Repeaters

Ⅶ Use of Repeaters in Ethernet 

Ⅷ Frequently Asked Questions About Repeater


Ⅰ What is a Repeater?

A repeater is a network device that retransmits a received signal with greater strength and to a larger geographical or topological network boundary than the original signal could.



A repeater is used in computer networks to increase network coverage, replicate a weak or broken signal, and/or support remote nodes. Repeaters amplify the received/input signal to a higher frequency domain, allowing it to be reused, scalable, and available.


Repeaters were first used in wired data transmission networks to overcome the limitation of a signal propagating over a greater distance, and they are now widely used in wireless networks to increase cell size.


Repeaters are frequently referred to as signal enhancers.


Ⅱ Types of Repeater

2.1 Telephone Repeater 

This is used to extend the transmission range of telephone signals in a telephone connection.


  • Land Line Repeater

They are most commonly found on trunklines that transport long-distance calls. An analog telephone line is made up of two wires and an amplifier circuit constructed of transistors that uses power from a DC current source to boost the power of the alternating current audio signal on the line. The wire pair carries two audio signals, one in each direction, because the telephone is a duplex (bidirectional) communication device. As a result, telephone repeaters must be bilateral, amplifying the signal in both directions without creating feedback, which significantly complicates their construction. Telephone repeaters were the first sort of repeater, and they were used in some of the first amplification applications. Between 1900 and 1915, the introduction of telephone repeaters enabled long-distance phone service. The majority of telecommunications cables are now fiber optic cables with optical repeaters (below).


Mechanically connected carbon microphones were utilized as amplifiers in telephone repeaters prior to the invention of electronic amplifiers. It was discovered after the turn of the twentieth century that negative resistance mercury lamps could magnify, and they were utilized. Around 1916, the advent of audion tube repeaters made transcontinental telecommunications feasible. In the 1930s, vacuum tube repeaters with hybrid coils were prevalent, allowing thinner cables to be used. In the 1950s, negative impedance gain devices were more prevalent, and the E6 repeater, a transistorized form, was the last major type employed in the Bell System until the low cost of digital transmission rendered all voiceband repeaters obsolete. From the mid to late twentieth century, frequency frogging repeaters were common in frequency-division multiplexing systems.


  • Submarine Cable Repeater

This is a telephone repeater that is used in submarine telecommunications cables.


2.2 Optical Communications Repeater 

This is used to extend the signal range of a fiber optic cable. Short pulses of light carry digital information across a fiber optic cable. Light is composed of particles known as photons, which can be absorbed or scattered in the fiber. A phototransistor transforms light pulses to an electrical signal, an amplifier amplifies the signal, an electronic filter reshapes the pulses, and a laser converts the electrical signal to light again and sends it out the other fiber in an optical communications repeater. However, optical amplifiers for repeaters are being created to magnify light without first converting it to an electric signal.


2.3 Radio Repeater 

This is used to increase the range of a radio signal's coverage. The history of radio relay repeaters began in 1898, with Johann Mattausch's publication in the Austrian journal Zeitschrift für Elektrotechnik (v. 16, 35 - 36). However, his "Translator" concept was crude and unsuitable for usage. Emile Guarini-Foresio designed the first relay system with radio repeaters that actually worked in 1899.


radio repeater is typically made up of a radio receiver and a radio transmitter. To offer coverage beyond the blockage, the received signal is amplified and retransmitted, generally on a different frequency. The installation of a duplexer allows the repeater to use one antenna for both receive and transmit.


  • Broadcast relay station, rebroadcastoror translator: A repeater is a device that extends the coverage of a radio or television transmitting station. It is made up of a second radio or television transmitter. The signal from the main transmitter is frequently transmitted via leased telephone lines or microwave relay.


  • Microwave relay: This is a specialized point-to-point telecommunications link that consists of a microwave receiver that receives information from another relay station in line-of-sight distance via a microwave beam and a microwave transmitter that transmits the information to the next station via another microwave beam. Microwave relay networks deliver phone conversations, television shows, and computer data from one city to another across continents.


  • Passive repeater: This is a microwave relay that is merely a flat metal surface that reflects the microwave beam in a different direction. It is used to send microwave relay signals over hills and mountains when amplification is not required.


  • Cellular repeater: This is a radio repeater used to improve cell phone reception in a small region. The gadget works like a miniature cellular base station, including a directional antenna for receiving signals from neighboring cell towers, an amplifier, and a local antenna for rebroadcasting the signal to adjacent cell phones. It's common in downtown office buildings.


  • Digipeater: A packet radio network repeater node. It performs a store and forward function, sending information packets from one node to another.


  • Amateur radio repeater: Amateur radio operators use it to provide two-way communication across an area that would otherwise be difficult to cover using point-to-point on VHF and UHF. Individual operators or clubs put up and maintain these repeaters, which are normally available for use by any licensed amateur. A hill or mountaintop position is desirable for constructing a repeater since it maximizes usage across a vast area.


Radio repeaters improve communication coverage in systems that normally use frequencies with line-of-sight propagation. Without a repeater, the curvature of the Earth and the blocking effect of terrain or tall buildings limit the range of these devices. A repeater on a hilltop or tall building can allow stations that are not in line of sight with each other to communicate consistently.


Radio repeaters may also allow translation from one set of radio frequencies to another, allowing two separate public service agencies to communicate with one another (say, police and fire services of a city, or neighboring police departments). They may also provide connections to the public switched telephone network or satellite networks (BGAN, INMARSAT, MSAT) as an alternate way from the source to the destination.


A repeater station typically listens on one frequency, A, and transmits on another, B. All mobile stations listen on channel B for signals and transmit on channel A. The difference between the two frequencies may be negligible in comparison to the frequency of operation, say 1%. The repeater station will frequently utilize the same antenna for transmission and receiving; highly selective filters known as "duplexers" separate the feeble incoming received signal from the billions of times stronger outbound sent signal. Separate sending and receiving stations are often employed, linked by a wire line or a radio link. While the repeater station is designed for simultaneous receipt and transmission, mobile units do not need bulky and expensive duplexers because they only transmit or receive at any one time.


A "talkaround" channel may be given to mobile units in a repeater system, allowing direct mobile-to-mobile operation on a single channel. This may be utilized if the repeater system is out of range, or for communications that do not require the attention of all mobiles. The repeater output frequency could be the "talkaround" channel; the repeater will not retransmit any signals on its output frequency.


An engineer will examine the intended coverage area and pick repeater locations, altitudes, antennas, operating frequencies, and power levels to provide a predictable degree of reliable communication over the designed coverage area.


Ⅲ How Does a Repeater Work?

The repeater action is analogous to a relay race. The transmitting station passes the signal to the repeater, which receives it and sends it to the receiving station. Because you press the transmit button to communicate and the release button to receive, only one side of the conversation is heard at a time.


The diagram below depicts the gear used to operate a repeater as well as the path the signals take. Here's a quick rundown of the components:


How Does a Repeater Work

How Does a Repeater Work?


Antenna: The majority of repeaters employ a single antenna for both transmit and receive. In general, it's a high-performance, long-lasting, and efficient omnidirectional antenna. They are elevated as much as possible above ground level.


Feedline: Repeaters employ hardline, a tough, low-loss cable. Actually, it resembles a flexible pipe with a central conductor rather than a cable. Because hardline has lower signal loss than traditional coax, more transmit power reaches the antenna and weaker signals can be received by the repeater.


Duplexer: The duplexer distinguishes and isolates the incoming and outgoing signals. It keeps the receiver and transmitter from interfering with one another and aids in the rejection of particularly powerful adjacent frequencies or other RF interference entering the repeater system. A duplexer is often made up of two parallel bandpass filters. There is no direct connection between the transmitter and the receiver since one filter offers a road between the transmitter and the antenna and the other provides a way between the antenna and the receiver.


Receiver: Repeater receivers are often exceedingly sensitive and selective, capturing signals that would be lost if sent directly from radio to radio. It is configured to receive input frequencies from radio transceivers.


Controller: This is the repeater's brain and is effectively a dedicated computer. It manages repeater station ID via CW or voice and activates the repeater as necessary. It also serves a variety of other purposes, such as making pre-programmed announcements or connecting many repeaters.


Transmitter: The transmitting section of most repeaters includes an exciter and a power amplifier. The exciter retransmits the received audio at the correct frequency, while the power amplifier amplifies its output.


Repeaters are network devices that retransmit data and divert signals to weak network access points. Data transmission and reception have various frequencies on both the sender and receiver sides. When the sender's and receiver's frequencies are matched, the Repeater operates.


Let us look at an example to learn more about Repeators.


Many of you have probably heard of the term Walkie Talkie. A Walkie Talkie has a straightforward connection. The data can be transferred to the receiver without any congestion or error. Only if there are no barriers in the middle of the transmission may data be transferred. Allow us to get into the subject in depth. Assume one person communicates with another via a one-to-one communication device, such as a walkie talkie. If there is a clear path between the distances, the data can be successfully sent. If there is a peak or hill in the way, the data cannot be delivered precisely.


An Antenna is installed between the two devices to avoid this problem. This device retransmits data to the receiver side and directs signals to weak spots. This is referred to as the repeater's primary function.


Please let us know how the repeater system is working. The data delivered from the sender to the receptor is referred to as an uplink, whereas the receptor that retransmits the same data in the other way and sends it to the receiver is referred to as a downlink. These repeaters, however, can also be employed in areas where there are no mountains or hills in the Way. We consider reports to be incredibly strong radios.


We have various portable repeaters that are more powerful than the 25 Watt mobile devices. These repeaters are stationed in specific geographic locations. The range of these routers is mostly 50 to 100 watts, and there are certain cable connectors that link to repeaters at fixed locations such as building towers or the tops of residential buildings.


Because of the presence of repeaters, all mobile or portable devices have access to a wide range of communication signals in all directions. These receptors provide a broad spectrum of communication for greater areas.


Ⅳ Features of Repeater

  • These repeaters are linked together at the physical layer.
  • It transmits signals to weaker places in order to boost the system signals.
  • These receptors connect the various network signals in order to convey data between the two devices.
  • These Repeaters can bridge the gap between two devices.
  • The Repeaters are capable of continuously monitoring the signals generated between the two LANs.
  • Electrical signals become weaker as they travel a greater distance. These Repeaters arrived at the location to strengthen the weak signals used in data transfer.
  • Repeaters can help with flexible networking.
  • The 30 repeaters attached to it are supported by multi-site connectivity options.
  • All of the Repeaters are linked together via an IP site connection network.
  • This IP network can respond quickly to any problem in the repeater network.
  • These receptors are capable of providing 100 percent digital communication. thus they don't have to wait for analog voice calls.


Ⅴ Advantages of Repeaters

  • Repeaters are easy to set up and can be used to extend the length or coverage area of networks.
  • They are inexpensive.
  • Repeaters do not necessitate any processing overhead. The only time they need to be investigated is when performance suffers.
  • They can connect signals with various sorts of cables.


Ⅵ Disadvantages of Repeaters

  • Repeaters are unable to connect disparate networks.
  • They are unable to distinguish between true signal and noise.
  • They are unable to minimize network traffic or congestion.
  • Most networks restrict the number of repeaters that can be deployed.


Ⅶ Use  of Repeaters in Ethernet

Repeaters are used to increase signal length and efficiency, hence they are utilized more in Ethernet.


An Ethernet repeater's primary role is to transmit a signal from one Ethernet cable to another without signal attenuation or loss of signal strength.


Whereas repeater systems aid in the detection of collisions. If a repeater detects a collision, it sends the signal to all associated ports.


A repeater is a device that connects many Ethernet segments together. This is usually done with a multiport repeater.


If there are more than five segments between two host devices, repeaters frequently identify incorrect links; in such a case, the data flow is interrupted until the Jat's data is correct or repaired.


Repeaters are intelligent devices that regulate and control signal flow. In order to protect the wires from damage or breaking.


Repeaters also allow network segments to continue operating even if one of them breaks or becomes unable to perform any function. As a result, repeaters are extremely beneficial to the seamless operation of wired networks.


Ⅷ Frequently Asked Questions  About Repeater

1. What is the Function of Repeater in Network?

A repeater is used to extend the signal over great distances in order to transmit it. It is able to reach the destination by extending the signal's range, which was not achievable with a router alone.


2. What is the Meaning of Repeater in Computer?

A repeater is used in computer networks to increase coverage, repair weak or broken signals, and service faraway nodes. The received/input signal is amplified to a higher frequency domain in a repeater, making it reusable, scalable, and available at any moment.


3. What is Repeaters in Networking?

Extenders (also known as repeaters) are devices that improve your network's signal intensity so that it can travel further. When utilized in this manner, the repeater divides the cable into two segments. There is a limit on the cable length in addition to the length limit on each side of the repeater.


4. Where is Repeater Use  d in a Network?

The physical layer is where a repeater functions. To increase the amount of time a signal can be transmitted over the same network, it regenerates the signal before it gets weak or garbled.


5. How Do Repeaters Work in Networking?

When a wireless repeater receives radio signals from a WAP, it regenerates and distributes them as frames. Wireless repeaters can improve wireless signal coverage. A repeater is installed in remote regions where network signals can travel but become feeble.


6. What Are the Main Functions of Repeater?

A repeater's role in telecommunications is to retransmit a signal. A repeater is used to send signals over extended distances or to receive signals on the other side of an obstruction.


7. What is the Function of Switch And Repeater on Network?

A network switch learns the identity of the connected devices and passes the data to the port corresponding to the device, as opposed to repeater hubs, which broadcast the same data out of each port and let the devices select out the data targeted to them.


8. What is the Purpose of Using a Repeater in Network Environment?

In networking repeaters, incoming electrical, wireless, or optical signals are regenerated in order to maintain signal integrity and extend data transmission range.


9. What is a Repeater Station And How Does It Work?

Resounding is an automated radio station that expands communication range. An integrated controller is connected to a receiver tuned to one frequency and a transmitter tuned to another.


10. What’s the Optimal Location to Mount a Repeater?

The best mounting site is determined by your structure and surroundings. Before installing the repeater, we recommend doing a radio coverage site survey to ensure optimal radio range and coverage. This entails positioning the antenna in an optimal central place and replicating the coverage that would be expected if the antenna were put in this location.


11. How is a Repeater Made?

A typical repeater is made up of five parts: an antenna, a duplexer, a receiver, a baseband processor, and a transmitter. The duplexer allows a single antenna to receive and transmit signals on several frequencies. A low-level signal is filtered and amplified by the receiver before it is processed and delivered to the transmitter.


12. How Does a Digital Repeater Differ From an Analog Repeater?

The primary distinction is in the baseband processor. The receiver voice is filtered and delivered directly to the transmitter modulator in an analog repeater. Any noise picked up will be transmitted to the transmitter. This repeater downlink will have noise increases from both the uplink to the repeater and the downlink from the repeater, regardless of what a radio receives. The baseband processor in the digital repeater transforms to binary bits, which are then error corrected and supplied to the transmitter. This downlink signal will be error corrected by the radio receiving the repeater, resulting in noise-free voice. Only when the signal in either the uplink or downlink becomes too weak does the voice decode begin to break up and drop out.


13. How Can I Improve the Range of a Repeater?

By increasing antenna gain, increasing transmitter power, or improving antenna placement. Ascertain that the coaxial cable connecting the repeater duplexer to the antenna is of high quality, low loss, and in good working order. Additionally, ensure that no interfering signals are jamming the receiver. When the channel is busy with a signal, the receiver squelch LED indicator might help.


This is feasible, but it becomes complex. On another site, you cannot simply invert the repeater pair. The frequency of a repeater downlink output cannot be the same as the frequency of a repeater uplink receiver input. To extend the range using only repeaters, you would need two more repeaters with two more sets of repeater pairs.


Ordering & Quality

Photo Mfr. Part # Company Description Package PDF Qty Pricing
JS1-5V-F Company:Panasonic Remark:General Purpose Relays 10A 5VDC SPDT SEALED PCB Package:N/A
In Stock:On Order
1+: $1.63000
10+: $1.53000
20+: $1.36000
50+: $1.30000
100+: $1.23000
200+: $1.09000
500+: $1.02000
1000+: $0.95200
AQY212GH Company:Panasonic Remark:Solid State Relays - PCB Mount 500MA 60V SPST Package:N/A
In Stock:On Order
1+: $4.80000
10+: $4.50000
25+: $4.28000
50+: $4.01000
100+: $3.79000
250+: $3.19000
500+: $2.96000
1000+: $2.79000
2500+: $2.71000
AQY214S AQY214S Company:Panasonic Remark:Solid State Relays - PCB Mount 100MA 400V 4PIN SPST Package:N/A
In Stock:On Order
1+: $4.22000
10+: $4.02000
20+: $3.49000
50+: $3.38000
100+: $2.50000
200+: $2.32000
500+: $1.50000
1000+: $1.21000
2000+: $1.16000
K4EB-24V-1 Company:Panasonic Remark:Relays relay Package:relay
In Stock:On Order
AQY212EH AQY212EH Company:Panasonic Remark:Solid State Relays - PCB Mount 60V 550mA DIP Form A Norm-Open Package:N/A
In Stock:On Order
1+: $4.35000
10+: $4.08000
20+: $3.63000
50+: $3.44000
100+: $3.26000
200+: $2.90000
500+: $2.72000
1000+: $2.54000

Related Articles

How to Test a Relay with Multimeter?

Apogeeweb 29 Jul 2020  13087

IntroductionA relay is an electronic control device, which has a control system (also called an input loop) and a controlled system (also called an output loop). It is often used in automatic control ...

Continue reading »

The Role of the Relay and Its Working Principle

Apogeeweb 17 Jan 2019  10241

Warm hints: This article contains about 4000 words and the reading time is about 18 mins. IntroductionA relay is an electronic control device that has a control system (also called an input loop) and...

Continue reading »

Symptoms of a Bad Starter Relay and How to Test it?

Apogeeweb 25 Aug 2021  15559

Catalog Ⅰ IntroductionⅡ Function of Starter RelaysⅢ How does a Starter Relay Work with Others?Ⅳ Location of Starter RelaysⅤ Symptoms of a Bad Starter Relay5.1 the Vehicle doesn&rs...

Continue reading »

How does a Latching Relay Work [Types, Diagram, Advantages and Disadvantages]

Apogeeweb 19 Apr 2022  4900

Catalog IntroductionⅠ What is Latching Relay?Ⅱ How does a Latching Relay Work?Ⅲ How do You Reset a Latching Relay?Ⅳ Latching Relay Circuit Diagram & WorkingⅤ Latching Rel...

Continue reading »

Reed Relay Basics Update | Uses in Switching Circuits

Apogeeweb 26 Jul 2021  3068

IntroductionAs one type of relays, reed relays use an electromagnetic coil to control one or more flexible ferromagnetic metal reed switches directly. It is composed only by the contacts themselves th...

Continue reading »

How to Replace the Fuel Pump Relay?

Apogeeweb 21 Jul 2021  4676

Catalog Ⅰ Definition of Fuel Pump Relay Ⅱ Function of Fuel Pump Relay Ⅲ Application of Fuel Pump Relay in Vehicles   3.1 The working principle of automobile rela...

Continue reading »

pinglun 1 comment

    • pingluntus
    • Nio danz on 2022/8/18 23:19:44

    More notes about HUBs

Leave a Reply

Your email address will not be published.

code image
Rating: poor fair good very good excellent

# 0 1 2 3 4 5 6 7 8 9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z