Low-Power FM Transmitter
A low-power FM transmitter designed for rural broadcasting applications, featuring Colpitts oscillator and PCB-integrated telescopic antenna.
Demonstration Videos
Project Files
Project Overview
This FM transmitter project addresses the need for reliable, low-power broadcasting solutions in rural and remote areas. The design emphasizes efficiency, range, and regulatory compliance while maintaining simplicity for field deployment and maintenance.
The heart of the transmitter is a carefully tuned Colpitts oscillator circuit, chosen for its excellent frequency stability and low phase noise characteristics. The oscillator operates across the standard FM broadcast band (88-108 MHz) with precise frequency control and minimal drift over temperature variations.
Audio input is captured through a high-quality microphone preamplifier circuit, with the audio signal modulating the carrier frequency through a varactor diode modulation stage. The PCB design integrates a telescopic antenna system optimized for the FM broadcast band, ensuring efficient radiation and maximum range within power limitations.
Key Features
- • 88-108 MHz frequency range coverage
- • Colpitts oscillator for frequency stability
- • Integrated microphone and audio processing
- • PCB mounted telescopic antenna
- • Low power consumption design
- • Rural broadcasting optimization
Challenges
- • Achieving frequency stability across temperature variations
- • Ensuring regulatory compliance for broadcast power
- • Minimizing harmonic distortion and spurious emissions
Outcomes
- • Stable FM transmission across 88-108 MHz
- • Reliable performance for rural broadcasting