Radiation properties of the Higher Order-High Gain Broadside Mode of a Microstrip fed Cylindrical Dielectric Resonator Antenna

A simple microstrip coupled cylindrical dielectric resonator antenna (CDRA) is capable of resonating at several frequencies, among which a few resonances (modes) exhibit excellent radiation characteristics. For a CDRA of high dielectric constant (εr = 24), in addition to the dominant HEM11δ mode, the HEM21δ mode is excited as the second mode, and the HEM123+δ mode as the third mode. The third mode is of great interest as it produces broadside radiation with a peak gain of ~ 9.8 dBi, which is about ~ 3.9 dB higher than that of the first mode and ~ 5.4 dB higher than that of the second mode. In the measurements, a peak gain of 9.4 dBi has been verified for the HEM123+δ mode.