AM Transmitters

AM (Amplitude Modulation) transmitters are used for broadcasting audio signals over the amplitude-modulated carrier wave. They are commonly used in AM radio stations and other applications where the transmission of audio content is required. AM transmitters consist of several key components that work together to generate and transmit the modulated signal. Here are the main components and their functions:

AM Transmitters
AM Transmitters

  1.     Oscillator: The oscillator generates a high-frequency carrier wave, typically in the range of several hundred kilohertz to a few megahertz. The carrier wave provides the base frequency for the transmission.
  2.     Modulator: The modulator combines the carrier wave with the audio signal to produce the modulated signal. In AM, the amplitude of the carrier wave is varied in proportion to the instantaneous amplitude of the audio signal. The modulator can be implemented using various techniques, such as linear amplifiers or switching circuits.
  3.     Power Amplifier: The power amplifier boosts the power level of the modulated signal to a level suitable for transmission. It ensures that the signal has sufficient strength to propagate over the desired coverage area. Power amplifiers used in AM transmitters are typically linear amplifiers.
  4.     Antenna: The antenna radiates the modulated signal into space, converting the electrical signals into electromagnetic waves. The design of the antenna depends on the desired coverage area and frequency range of operation. AM antennas are typically tall vertical structures or wire antennas.
  5.     Control and Monitoring Circuitry: AM transmitters include control circuitry to adjust and monitor various parameters, such as carrier frequency, modulation depth, and power output. These circuits ensure the transmitter operates within regulatory limits and provide control capabilities for optimal performance.
  6.     Power Supply: The transmitter requires a stable and reliable power supply to provide the necessary electrical energy for its operation. Power supplies for AM transmitters can range from AC mains power in fixed installations to generators or batteries in remote or emergency situations.


AM transmitters are regulated by government authorities to ensure they operate within allocated frequency bands and adhere to specified power limits. The design and specifications of AM transmitters can vary depending on factors such as the desired coverage area, power requirements, and regulatory constraints.