VHF quadrature hybrid coupler with the crossed strips

Abstract

In this study, the construction of the hybrid, with the crossed strips, is presented. The hybrid is designed as a broadside-coupled suspended strip-line coupler, with the crossed strips, for the frequency range from 150 MHz to 200 MHz, with the central frequency at 175 MHz. The strips made of brass, with the Teflon substrate between them, are placed inside the aluminum casing filled with air. The hybrid has to direct the sum of the two input signals, ports 1 and 4, towards an output port (port 2 or 3), leaving nothing at the second output port (port 3 or 2). The input signals have 16 KW of power each, while the output signal has 32 KW of power. Knowledge of the conditions, which must be satisfied by the hybrid, enables the acquisition of dimensions of the hybrid, through the process of EM simulation. The values of the S-parameters of the simulated coupler are being compared, to the values of the S-parameters of the produced coupler to validate the design process.