The application of printed-circuit techniques to the design of microwave components

A brief résumé is given of the basic theory of strip transmission lines including unwanted effects such as spurious mode transmission and radiation. A variety of materials and different printed-circuit techniques have been tried and the relative merits of each are discussed. A technique of measurement is described and details are given of two pieces of specially developed measuring equipment in microstrip, namely an adjustable short-circuit and a wide-band precision attenuator. A number of new broad-band components covering the range 2500¿4200 Mc/s are described; they include a reverse-phase hybrid-ring circuit, a back-to-back slot-coupled 3 dB directional coupler, and a new type of low-pass filter. The paper concludes with a description of an r.f. head for two-way communication equipment used in propagation testing.