A microwave panoramic noise-spectrum analyser

The paper outlines briefly the direct-detection and superheterodyne principles of noise-spectrum measurement, and discusses the design of two forms of microwave panoramic noise-spectrum analyser. Details are given of a superheterodyne system capable of displaying automatically microwave oscillator noise at carrier/noise ratios as high as 177 dB per c/s with a display range of 40 Mc/s. Superheterodyne and frequency-modulation direct-detection spectrum analysers require the incorporation of a carrier-suppression filter, two new forms of which are also described.