Hybrid Electromagnetic and Non-Linear Modeling and Design of SIW Cavity-Backed Active Antennas

This paper presents the modeling and implementation of planar passive and active cavity-backed antennas in substrate integrated waveguide (SIW) technology. The cavity-backed topology helps suppressing the undesired surfacewave modes and may provide better phase noise performance in the antenna oscillator. The use of SIW technology allows for a compact and costeffective implementation of the structure. The design of the active antenna involves both electromagnetic full-wave modeling for the radiating structure and nonlinear analysis of the active circuitry through harmonic balance and transient simulations. Single substrate prototypes of both passive and active antennas operating in X band are presented and measured, showing good agreement with simulated results.