A Broadband Microwave Noise Generator Using Zener Diodes and a New Technique for Generating White Noise

A microwave noise generator using Zener diodes as the source of noise has been designed and built. It generates almost constant noise power about 20 dB above the noise floor up to 3.2 GHz. The noise generator circuit employs two independent current sources and two identical Zener diodes to generate independent noise powers optimized for lower frequencies (<;1.4 GHz) and higher frequencies (>1.4 GHz). When the noise powers are combined on the same resistive load, the result is an almost flat noise power over the measured spectrum.