Circuit Lake

Electronic Project and Circuit Collection

Doppler Radar System

01/20/2010 Category: Monitoring, PIC, Project

This Doppler Radar System Project enables you to track speeding motorists in your neighborhood. It measures motorists speed using frequency (Doppler) shift. Steve Lubbers as the project designer explains that the speed radar will generate a microwave energy burst using a 10 GHz Gunnplexer transceiver. The energy burst can be modulated using a PWM output. The microwave signal will bounce off of a moving object, creating a Doppler shift of the transmitted frequency.


The received signal will be fed to a Fast Fourier Transform (FFT) to determine the shift frequency. The shift frequency will be converted to a target speed in miles per hour, and the target speed will be displayed on an analog display and transmitted to a serial port.

The Doppler Radar hardware consists of a microwave Gunnplexer hooked to a modified Microchip dsPIC30F4012-based Starter Board. The Gunnplexer provides the microwave front end. An op-amp based amplifier section conditions the receive signal. The Microchip Starter Board pulls together the digital hardware components of the system.

Doppler Radar
Download Project Documentation (zip)