Manipulation of antenna-mode radar cross-section in patch antennas

The Radar Cross-Section (RCS) of an antenna has two main components: structural RCS and antenna-mode RCS. Structural RCS is due to the physical geometry of the antenna. The antenna-mode RCS component is due to load impedance mismatches and can be manipulated by changing the load impedance connected to the antenna. This thesis explores the behavior of antenna-mode RCS when the load of a simple patch antenna is changed. The load is iterated through equally spaced points on a fixed Voltage Standing Wave Ratio (VSWR) circle on a Smith chart. The behavior was simulated at the fundamental frequency and the first and second harmonics. The patch antenna and the various loads were fabricated, and the actual change in RCS was measured in an anechoic chamber. The simulation data is compared to the measured data. It is seen that a predictable change in RCS occurs as load points are moved around a constant VSWR circle