Frequency-selective substrate integrated waveguide front-end system for tracking applications

Abstract

A K-band frequency-selective front-end system for monopulse tracking applications is presented on a single layer of a substrate-integrated waveguide (SIW). The circuit comprises an antenna array of two Vivaldi antennas, a frequency-selective power combiner, and two frequency-selective SIW crossovers, which eliminate the need for subsequent filtering. Its performance is demonstrated in terms of sum and difference patterns, gain, and scattering parameters. In order to validate the design procedure, the monopulse tracking front end is fabricated and measured. It has a bandwidth of 540 MHz with an operating frequency range of 23.63-24.17 GHz. The sum and difference patterns are provided by in-phase and out-of-phase electric fields. The maximum achievable gain is 6.2 dB at the mid-band frequency, and a 30-degree field of view is obtained. The measurements are found to be in good agreement with simulations.