Analysis and design of probe-fed printed annular rings

A coaxial connector is a robust and efficient technique to isolate the feeding network from the radiating patches. Unfortunately, probe-fed patch antennas suffer from inherently narrow impedance banwidths, typically 2-3%. One common means to improve the bandwidth is to use an electrically thick substrate. However, a special attachment mode must be used to accurately predict the RF performance of a probe-fed patch antenna utilising an electrically thick substrate. We present an attachment mode for probe-fed printed annular ring antennas. The attachment mode is incorporated into a full-wave spectral domain analysis. Several design examples are presented. Insight into the design philosophy of probe-fed printed annular ring antennas is also addressed.