VHF quadrature hybrid coupler

In this paper the practical design of a VHF quadrature hybrid coupler is presented. Knowing, before the production, the conditions that the coupler has to satisfy, has enabled us to acquire, through computer simulation, the dimensions of the coupler that was later produced. Values of the S-parameters of the simulated coupler are compared, to the values of the S-parameters of the produced coupler to validate the design process. The coupler is designed as a broadside-coupled strip-line coupler, for a frequency range from 150 MHz to 200 MHz, with a central frequency at 175 MHz. It consists of two overlapping strip-line brass conductors, placed in an aluminum casing filled with air. The purpose of the coupler is to combine two input signals in the quadrature, which have 16 KW of power, into an output signal of 32 KW.