Transponder

A Transponder we can say that it is a controller device that picks up and automatically responds to an incoming signal or whatever the input is coming in the machine, so this is a combination of transmitter and responder which is called a transponder. Also, a transponder is an electronic device that produces a response when it receives a radio frequency interrogation, or we can say a communication satellite transponder is also used between receiving and transmitting the Antennas for the signals. There are two functions of the Transponder which can be said to amplify the received input signals which is received in a format and then translate the frequency of it. It is a wireless communication device that takes the incoming signals automatically and then to it.

What is Transponder?

A transponder is a device that receives some radio signals and then automatically transmits some different kinds of signals also we can say that it is a device that on receiving a signal emits different signals in the response. 

Transponders are used for detecting identifying or location locating any object, but they can also be used in some other Technologies and satellites or in communication signals. It refers to the subsystem of the transmitter and receiver on board the satellite which amplifies the range of frequencies to another location on the earth.

It turns up the input signal and translates the frequency of the signals which are received and main function is to transfer the received signals.

Block Diagram of Transponder

Working Principle of Transponder

Transponder is like an electronic circuit which has receiver and transmitter generally we see transponder and  satellites and in satellites they receive the signal from the ground stations and then retransmit and broadcast  to the earth stations, Transponders will also do functions like signal amplification noise reduction and  frequency conversion. 

The transponder works with radio frequency and then respond to the monitoring or the controlling of the  devices and the Signals and Communications once a signal is sent transponder react by simply returning and  other signal information within the response change which is based on kind of transponder although it also  contain codes or the location of the aircraft in any machine the transport automatically transmits back a radio  signal at a fixed frequency to transmit and receive Signals concretely transmitting and receiving signals should  be set at the dissimilar frequencies. 

Uses of Transponder

Transponder is used in Aircraft satellites, advanced vehicles, underwater, vehicle keys many more. 

• Aircraft: A transponder is used as a part of a system that provides some altitude information.
• Satellite: It helps from communication by receiving and transmitting the signals in a satellite there  are many Transponders in a single satellites and which support sum of kind of signals.
• Advance Vehicles: It helps to receive the signals in vehicles and used to receive the audio video  signals as well as.
• Underwater: transponder or we can say as soon as transponder which measures the distance based  on underwater location. 
• Vehicle Key: It was also used in a key in the form of a small ship in car keys. 

Classification of Transponder

Basically, there are three main types of Transformers A, C and S Transformer. 

• In transponder A it sends back a transformer code to ATC  
• In transponder C it sends a transformer code + altitude information to ATC  
• In transponder S it sends a transformer code + altitude information to ATC and receives and reports  information to other transponder of the same type. 

Working of Mode-A Transponder

Mode A transmits the identifying code only not the other one , in mode A transponder it is the most basic transponder mode in it only transmits the four-digit squawk code  and useful for identifying an aircraft its position and but not much about it so that’s why mode A and mode C  are usually combined. This is also referred to as Mode 3A which means temporary identity of the aircraft.

Working of Mode -C Transponder

Mode C gives the identifying code and the altitude to the ATC, mode C Transporter it is the most widely used transponder mode and it provides information on the aircraft’s  pressure altitude it usually combines with the mode A, aircraft which can receive aircraft code position  altitude, so it is normally referred to as mode C. This provides information regarding the vertical position of the aircraft .This mode an be turned off if it sends the incorrect position of the aircraft.

Working of Mode -S Transponder

In this data exchange can done and also has altitude capability, each of this transponder is provided with a unique address code. mode S transponder is the short its short form is mode select it is a type of transponder that offers advanced  communication capability then mode A or mode crowded so whenever we use the S transponder it transmits  a variety of information to ATC and other aircraft.

Types of Transponders

The types of transponders are classifies as follows:

• Active or passive transponder
• Bent Pipe Transponder
• Regenerative transponder
• Satellite transponder
• Aviation transponders
• Radar transponder
• Automatic dependent surveillance broadcast transponder
• Telecommunications transponders
• Fiber optic transponder
• RFID transponders
• Sun pass transponder

Active or Passive Transponder

In passive transponder the power sources external and in active transponder power sources is intercalative transponder is cheaper than the active transponder also the passive transformer is smaller size compared to the  active transponder. In active the internal power source is present whereas in passive one there is no internal power source and requires no power . This is also known as active tag and passive tag.

Bent Pipe Transponder

The bent pipe transponder it is just a terminology which is used when signals are sent in return like in  a regular traffic will be considered to go back and return to where they came from. Bent pipe represent  u- shaped flow of signals sensor transponder is just a signal repeater that bounces by the any signals  received after their process and amplified.

Bent Pipe Transponder

Regenerative Transponder

Regenerative transponder is also known as processing transponder on the other hand besides the  performing the functions of the band type transponder it regenerates the Signals and Modulation and  perform steam modulation of the radio frequency carrier to the baseband. This regenerates signals and also performs demodulation , most probably it is suitable for the digital signals.

Regenerative Transponder

Satellite Transponder

Satellite transponder performs two functions which involves translation of frequency and received  input signal amplification there are two types of satellite transponder like bend Pipe and regenerative  type which are discussed above. The capacity of satellite transponder is measured in megahertz MHz.

Satellite Transponder

Aviation Transponder

Aviation transponders are used in Aircraft for Air Traffic control and identification purposes the  receives signal from the ground-based systems and transmit a response which involves information  about aircrafts identity altitude and other data and helps in tracking and monitoring aircraft during the  flight. 

Radar Transponder

Radar transponder redirect Transformer Adivasis used to enhance aircraft visibility on redial system  they receive radar signal from a ground based with a system or any other aircraft and transmits a response signal back to the source which allows should a system to detect and locate the aircraft more  accurately. 

Automatic Dependent Surveillance Broadcast Transponder

Automatic dependent surveillance broadcast transponder is used in aviation for surveillance and  tracking purposes they receive GPS signal and transmit information about aircraft position altitude  speed and other data to ground based receivers and other aircraft with ADS B systems. 

Automatic Dependent Surveillance Broadcast Transponder

Telecommunications Transponders

Telecommunications transponders are used in various communication system and satellite  Communications they receive incoming signals amplify them and transfer them to their  destination. 

Telecommunication Transponder

Fiber Optic Transponder

Fiber optic transponder is used to transmit and receive optical signal using a fiber by its data speed in  highest distance signal can move and function of this transponder is to optical and electrical signal  conversion and controlling Serializing and de-serializing. This sends the optic signals over a fiber and converts short range signals to long range signals through fiber optic.

Fiber Optic Transponder

RFID Transponder

RFID transponders are used in RFID they are also known as tax which provide unique and specific  identification which exist within chip or memory a smart card transponder with extra memory store a  lot of data as compared to simple ID number capacity is utilized in different payment location access  and other applications which stores the data. 

RFID Transponder

Sun Pass Transponder

Sun pass transponder is used in different countries where is red passes accepted this provides drivers  ease of tools paying automatically by letting norms to travel by single tool account. 

Sun Pass Transponder

Transponder Types in Controlling Air Traffic

There are three main types of transponders: A, C, and S. 

Transponder types in Controlling Air Traffic

Modes of Transponder

• Military Transponder Modes: Usually, mode one to mode 5 is military transport or modes while modes  A,B,C and S are similar transponder modes mode B and mode D are not in use only mode A C and S are  operational. 
• Civilian Transponder Modes: Mode A mode B mode cord D and mode as are called civilian  Transformer modes. 

Transponder Requirements

• VFR Aircraft with no other code assigned Hijacked Aircraft 
• Aircraft with Radio Failure 
• Aircraft in an Emergency State 
• In Class A B C all aircraft are equipped with mode c transponder  
• In class D as space does not need Transformer because Pilots need only two-way Radio  Communication  
• Requirement will vary in Class A space based on height of the aircraft. 

Advantages and Disadvantages of Transponder

There are some list of Advantages and Disadvantages of Transponder given below :

Advantages of Transponder

• Functionality: It improves functionality. 
• Convenient: It is simple to use and handle. 
• Secure : It is more secure and stable to use.
• Decarbonization: It decreased use of diesel and emission of Co2  
• Data Entry : It permits motor Carriers for getting data quickly from governing agency. 
• Efficient: It improves efficiency and productivity of motor Carriers and drivers. 

Disadvantages of Transponder

• Expensive : The introductory cost, for instance segment and installation cost are very high.
• Loss: Congestion of frequency can cause destruction of communication service. 

Applications of Transponder

• In Radio Telecom 
• In TV broadcasting  
• For voice correspondence  
• In military applications and roots  
• In internet applications.

Conclusion

Transponder react to the incoming input in a device and gives the output , it is the controller device used in various technologies. In communication satellites it receives some signals over some range from a satellite  or ground station then a transponder then amplifies them and then again retransmits them on different  frequencies so that it can be received on earth without changing any content of the received signal. So basically it receives input signals , amplifies it and gives output signal.

FAQs on Transponder

1. What is the difference between transmitter and transponder?

A transmitter device sends the signal and whereas transponder is a receiver which is coupled to the transmitter , so transmission will be sent.

2. What is the main function of transponder in satellite?

The main function of transponder in satellite is to transfer the received signals.

3. What is a transponder key?

It is a key which has RFID in the key , which adds extra layer of security to the vehicle’s ignition.