Microwave Module - Decatur Electronics SI-2 Technical Manual

System interface

Table of Contents

MICROWAVE MODULE

The microwave module of the SI-2 consists of a directional Gunn oscillator assembly, which is connected to

a machined horn lens antenna. The antenna radiates and receives the microwave energy and returns the

Doppler signal to the receiver section. The receiver section contains two coupled high-sensitivity mixer

diodes that receive the Doppler-shifted transmitted signal and a small amount of the microwave energy from

the oscillator. The mixer diodes mix these two signals to produce two low-level output signals with a

Doppler frequency shift of approximately 72Hz per mph of the target velocity and a phase shift between

them to determine the target direction. Two coax cables connect the Doppler signal to the DSP board, and

two wires connect the Gunn Oscillator to it.

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Si-arcade