Square Coaxial Beam Forming Network for Multilayer Microstrip Antenna

This paper presents the design of square coaxial beam former and its transition from square coaxial line to microstrip line. Impedance matching has been achieved by creating a groove discontinuity in inner conductor. A cone has been provided for smooth impedance transformation for required broad banding. The measured performance of the beam former has been obtained by feeding it to feed layer of the electromagnetically coupled multilayer patch antenna. Equal and unequal power divider has been designed with proper impedance transformer by changing dimensions of the inner conductor keeping same outer conductor dimensions. Smooth linear taper has been provided at impedance transformer junction. High power calculations are also presented for SCL to handle several kW of power.