What is Transmitter: Definition and 123 Discussions

In electronics and telecommunications a transmitter or radio transmitter is an electronic device which 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 component parts of all electronic devices that communicate by radio, such as radio and television broadcasting stations, cell phones, walkie-talkies, wireless computer networks, Bluetooth enabled devices, garage door openers, two-way radios in aircraft, ships, spacecraft, radar sets and navigational beacons. The term transmitter is usually limited to equipment that generates radio waves for communication purposes; or radiolocation, such as radar and navigational transmitters. Generators of radio waves for heating or industrial purposes, such as microwave ovens or diathermy equipment, are not usually called transmitters, even though they often have similar circuits.
The term is popularly used more specifically to refer to a broadcast transmitter, a transmitter used in broadcasting, as in FM radio transmitter or television transmitter. This usage typically includes both the transmitter proper, the antenna, and often the building it is housed in.

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  1. T

    Sequel of "Impedance Matching when the Transmitter, Line and Load...."

    Then might be regarded as continuation of discussion https://www.physicsforums.com/threads/impedance-matching-when-the-transmitter-line-and-load-impedances-are-different.1009266/ where unfortunately it's not more possible to post further replies (why?). So I would like to continue it here, since...
  2. T

    Impedance Matching when the Transmitter, Line and Load impedances are different

    Assume we have a general rf system where source with impedance ##Z_S## transfers a signal to a load with impedance ##Z_L## through a transmission line with impedance ##Z_T##. We want to match this system in order to maximize it's effiency: In https://en.wikipedia.org/wiki/Impedance_matching...
  3. T

    How Does Project 122 Snap Circuit AM Transmitter Work?

    Hi, guys! Could anyone provide an explanation about how the following AM transmitter works? It is similar to the AM transmitter for project 122 of the Snap Circuit kit by Elenco. Does it work as a switching modulator?
  4. G

    RF transmitter inside a metal enclosure, re. reflections

    wavelength is .3 m to 6m, a 3m waveguide can do up to the 6m λ, so it will reflect all the frequencies concerned
  5. nduka-san

    Electrical Raspberry Pi Zero W receiver / transmitter

    For a project that I'm making it has a raspberry pi 0w as its cpu for running autonomously, But I want to make use the raspberry pi 0w as the receiver as well. The range needed is about 3000 feet minimum. Currently I have been looking at some rc and drone receivers that would work as well, but I...
  6. S

    Description of a telemetry transmitter

    Hi, the following statement is taken from the telemetry standard IRIG Standard 106-11: The RF signal is typically generated by filtering the baseband non-return-to-zero-level (NRZ-L) signal and then frequency modulating a voltage-controlled oscillator (VCO). The optimum peak deviation is 0.35...
  7. N

    How to transmit a signal (530 - 550 Khz) to a point

    Hi everyone, I'm pretty new to electromagnetism and have no experiences in this topic. I have a signal generator (Digital Dual Channel Funktion Signal Generator) and want to generate two signals (530 and 550 Khz signal) and want to transmit these generated signals to the points on a table...
  8. T

    Homework Help - Transmitter for dP

    Hello. I've got a last homework before the summer, which is due to be handed in tomorrow. The question is the following: "How is it possible that a normal transmitter, used for measuring differential pressure, can get the label FT, PT, LT in a process scheme?" Of course, the labels stands...
  9. D

    Can you build an FM transmitter with a crystal oscillator

    Can you build a fm transmitter with A crystal oscillator? I already have a 100 megahertz crystal oscillator. I can't find instructions on how to do That on the internet.
  10. M

    Radiofrequency communication through tissue

    Hello, I am a Biologist currently working on a Biocommunication related project. To explain the project, I am going to use a Piezo sensor attached to the bone and it can detect bone cracks using EMI. I would first energize Piezo sensor with certain frquencies and it generates Ultrasonic waves...
  11. T

    How Do Microwave transmitters work without physical connections?

    So I recently picked up 40 of 10.525 GHz Microwave RADAR transmitters: I opened up one out of curiosity and had something like this (image attached) . I noticed some parts of the PCB aren't even connected to anything. How do the different shapes and sizes of the PCB interact with each-other...
  12. C

    Find the maximum amplitude of the induced EMF

    Homework Statement [/B] A radio transmitter radiates isotropically at the frequency of 90.8 MHz. The peak magnetic field at a receiver, 9km from the transmitter, is ##9x10^{-10}T##. Calculate the maximum amplitude of the induced emf in a 12 turn coil with area A = ##90cm^{2}## at the receiver...
  13. GhostLoveScore

    Effect of high SWR on transmitter

    I've been reading about effect of high SWR in antenna system on my ham radio. A lot of people are talking something like - You can't have SWR higher than 1.5 to 1, it will blow final transistors of your transmitter. I've read about it and it doesn't look to be true. In fact, it seems like power...
  14. OldWorldBlues

    Basics of radio for a focused transmitter

    Hi there! I'm looking to create a small (max 20 foot range) radio transmitter, to direct a focused radio beam at a receiver, for the purpose of remote switching. Ideally, I would like the device to work at a relatively "exotic" frequency, as I would think there is a lot of radio noise where I...
  15. V

    Safety concerning ERP of transmitter

    I'm curious to figure out if I'm operating a transmitter with safety compliance regarding its HERP (Hazards of Electromagnetic Radiation to Personnel). Put simply, the transmitter has a low and high output capability of 2w and 10w. The antenna it operates on has an 11db gain. Radiating around...
  16. N

    Transmit/Receive analog signals

    I'm completely new to transmitting/receiving signals, but I wanted to get a scope of what kind of components are out there that I could use to build this system. I wanted to read the voltage drop across a resistance thermometer (Vt) and send this signal wirelessly to another circuit, where I...
  17. maearnie

    Microwave transmitter question

    Can someone enumerate the equipment needed in a microwave transmitter control room? i already searched the net and i somehow don’t understand anything haha. also can you please explain what each equipment does? thank you :)
  18. Cool4Kat

    How did Armstrong's FM receiver and transmitter work?

    Hey, I was wondering if any of you smart people could help explain in a very simple way (if possible) how the first FM transmitter and receiver worked? I know, for example, that many current transmitters use a voltage variable conductor to change the frequency of the wave. Did Armstrong do...
  19. L

    WiMAX Transmitter: Can 1 EXAbit/sec be Transmitted?

    I was reading about WiMAX networks and how they can provide a 30mbit connection to a user 50km away! Now, I don't have a great understanding of data transfer but I assume inverse power law applies?? Pf = Pi / 4*pi*r^2 At 50km Pf = Pi / 10^10 * pi For Pf = 30mbit/sec = 30*10^6 Pi must equal...
  20. Tesladude

    Does Using Multiple 20mW Transmitters Increase Remote Control Car Range?

    I have built a remote control car, pwm speed controll and all, using picaxe microcontrollers and gained a lot of experience doing it. I used a low power i think 20mw transmitter you can find all over ebay that uses a 433hz carrier wave. A long time ago i found a 1w transmitter meant to be a step...
  21. T

    Relationship between an EM wave and its current

    Given the following: A directional radio wave transmitting antenna which creates a beam (diameter in mm), a current in volts, and a frequency (Hz), is it possible to calculate the em wave voltage (v/m or w/m2) immediately next to the antenna? and then at a distance of 10meters? What...
  22. ghost313

    Can quantum physics explain the workings of transmitters and receivers?

    Hello :) So my question are: -how to build a transmitter and a receiver? -how do they actually work?(in detail,microscopic and macroscopic) -which scientist was the one who invented this tech and if possible,are there any papers published that can be red today? Thank you for your time.
  23. U

    What's different between a receiver & transmitter antennas?

    Hello, I'm currently working on satellite model for high-school compatition, and I'm not sure if there's a visual difference between a reciver & transmiter antenas (on satellites)... Also, is it possible to satellite to recive a radio wave information from another satellite Thank you
  24. T

    What method does a receiver or transmitter use to approx....

    Hi, I'm just curious because I know wifi uses digital FFT to send and receive signals. (I can't really remember why) But when I imagine a signal being sent its like a squiggily wave, so what method does the reciever use to approximate the instantanious values of the signal into a mathematical...
  25. cnh1995

    Spark Gap Transmitter: EM Wave Generation & Transmission

    I recently read about the early spark gap transmitter..But I don't understand how the EM waves are generated and transmitted..Induction coil creates sparks in the gap but what produces the waves and how are they transmitted?? Need I study electromagnetic waves in detail??
  26. E

    Exploring Photon Transmitters and Receiving Antennas

    If instead of sending electromagnetic wave in transmitting antenna by shuttling electrons.. what would happen if we emit photons from photon emitters like in double slit.. would receiving antenna that receive wave receive the photons?
  27. L

    Advice on building a radio transmitter in the Radio Control band

    << Mentor Note -- post separated out of a different thread to deal with a separate question >> Hi, I am looking transmit as well as receive power within close proximity. Currently I am looking at 27.255 MHz AM in the citizens band. It is listed on Wikipedia and in statues I found to be for...
  28. Dark_Capacitor

    FM transmitter not transmitting

    I studied the working of the fm transmitter and end up making my own. The first part is amplifier and second (right) part is colpitts oscillator. The circuit works good on simulator. The output is AM modulated wave lying in fm band so it could be detected by radio easily but the circuit is not...
  29. G

    Molecules With Radio Emission Under Current

    I am working on a project, however I am having trouble finding the right material for it to work. I am looking for a nano-material or any molecule that will emit a radio frequency when subjected to a voltage or a current at around 37 degrees Celsius. I would really appreciate it if someone could...
  30. Tesladude

    Use 433MHz transmitter for video rca?

    Hi I want to transmitt a video rca signal with dome of the 433mhz transmitter and receiver modules you can get on ebay for cheap. I have used them a lot and have accomplished transmitting data through picaxe microcontrollers successfully. But could I use it to transmitt a video rca signal...
  31. T

    Trying to triangulate position of rogue radio transmitter.

    First off, this is my first post here. If this is in the wrong section I apologize and ask that it be moved. I am a amateur radio operator. We have experienced issues with a rogue radio operator recently, who is maliciously transmitting noise. I think it is possible to determine his position...
  32. O

    What would happen if I were close to a powerful transmitter?

    I saw some AM broadcast radio towers, several to form an array in order to direct the energy dependant on the time of day. I guess they covered 500+ meters, horizontal. I am now listening to shortwave transmissions on youtube, of things like OTH radar. I wonder in both cases, what...
  33. J

    What is the difference between NANC transmitter and co-transmitter?

    Hi all, I was just wondering, what is the difference between non-adrenergic non-cholinergic (NANC) transmitter and co-transmitter in the synaptic communication between neurons? In particular, what are their different functions? Many thanks, Jay
  34. H

    Understanding the Legalities and Limitations of Building a PM RF Transmitter

    How can I build a transmitter using radio waves with pulse modulation (Which I think [PM] means sine waves that either transmit or don't)? I can't find anything on how to build a PM transmitter, I can only find FM/AM ones, and I'm not smart enough to convert that information to the way I want...
  35. E

    Pressure Transmitter Installation at 410 deg C

    Hi, I have an application of pressure transmitter at 410 deg C max. process temperature. Transmitter can withstand only up to 350 C at Atm pressure. The original length of tubing for maximum working Temp of 310 C is shown in the attach file (Sketch B) and We are planning to extend the...
  36. N

    Why modulate the data sinusoid onto a transmitter sinusoid?

    Why modulate the "data" sinusoid onto a "transmitter" sinusoid? (Sorry about the simple question but this stuff isn't exactly my specialty) From howstuffworks.com ... Why can't you just send the sine wave produced by a person's voice directly through the air (or whatever channel you are...
  37. dexterdev

    Transmit With 5W FM Transmitter & Dipole Antenna: Range & Radiation Pattern

    With a 5W FM transmitter and a normal dipole antenna , to what range can I transmit. To be more specific, what will be the radiation pattern like (Can I get signal uniformly as in a circle where the center is antenna). Using which antenna, can I achieve maximum range omnidirectionally...
  38. E

    Knowing the Refractive Index of a Prism using Microwave Transmitter

    Homework Statement A prism of 90-45-45 was placed between a microwave receiver and transmitter. What steps should I take to know the index of refraction of the prism given that its material is not transparent to microwave? I positioned the prism so that a side of the prism is perpendicular to...
  39. A

    What is the job of a radio transmitter

    I am kind of confused. Does the radio transmitter modulate the waves or change it into alternating current. If it does both then which one is done first? Thanks for your help.
  40. A

    How Do You Calculate Component Values in an FM Transmitter Circuit?

    Homework Statement Hi I am weak at circuit, but I need to analyse how this circuit works and to determine the values of C4, C5 ,C6,C7, and L1. I need help for the understanding function of the whole component and determine the values of these component Homework Equations f=1/2√LC...
  41. A

    Implementation of Transmitter and Receiver for GPR

    Hello, I am a final year student of BEE Telecom. I chose my Final Year Project to design a Transmitter and Receiver for GPR. GPR has already been developed in my institute. It uses VNA as its source. Since VNA is a multipurpose device and the already-implemented project used it to find S11...
  42. C

    Laser Audio Transmitter Project Question

    Hi everyone, I'm attempting the laser audio transmitter project. And example of it is found here: http://www.freeinfosociety.com/site.php?postnum=2310 I'm quite new to electrical engineering type work, and am a little confused by why the circuit works the way it does. The diagram is this...
  43. R

    Combine bluetooth transmitter in a school project

    hey im in 11th grade and I am in a electorinc trend at school, we have to make a project for school and i want to combine bluetooth technology in it. i looked i looked Through the internet for guilding- how it is built, are there any protocols, how to use / transmit/recive - everything. so far i...
  44. F

    Can someone explain the workings of this FM transmitter circuit in detail?

    I am a beginner at circuit design.i need to find a way to explain how an fm transmitter works which i do not so any of you my sincere friends can explain to me how the circuit below works and does the necessary calculations I'm in your debt Here is sample proteus file and circuit diagram :
  45. M

    Low Power FM transmitter explanation

    Hello everyone, Finally I found a useful website where I can find the answers of my questions:) I will take signal processing course soon and I thought "building a low power fm transmitter" is a bright idea to train myself to a certain level... Though I need your help and I don't have...
  46. 0

    Transmitter uses radio waves or any type of waves

    Hi: I'm new in this site I need help here please I need a circuit that works as : 1- transmitter uses radio waves or any type of waves 2- sends waves for long way more than 3 km 3- consist of simple component than can be found in old electronic instruments such as old TV or radio...
  47. TestTubeGames

    Tesla Coil as Power Transmitter

    I've been trying to hash this problem out with some friends of mine, but we haven't been able to find a satisfactory answer: Tesla coils are (in an extremely basic sense) like a transformer. There are two coils of wire... the first one having a large current and not-so-large voltage. The...
  48. M

    Orientation of Receiver Antennas given orientation of transmitter

    Homework Statement An electric dipole antenna used to transmit radio waves is oriented vertically. At a point due north of the transmitter, how should a second electric dipole antenna be oriented to serve as a reciever? Homework Equations Im not sure if my answer below makes sense, is...
  49. I

    Pick up gps transmitter chip signal on android app

    Hi, i would like to make an android app and a gps transmitter. Where do i start? (Sorry if this is in the wrong section)
  50. L

    Research for novel: spark-gap transmitter

    (Please go ahead and move this if it's in the wrong section.) I'm a science fiction writer doing research for my latest book and hoping someone can help. A technically competent character (far more competent than me with my long-ago high school physics) - let's call him Jake - needs to build...