Broadband EBG resonator antenna using a combination of different dielectric substrates

A novel design of an electromagnetic band gap (EBG) resonator antenna with a wide gain bandwidth at Ku band is presented. The bandwidth enhancement of the antenna is attributed to the positive reflection phase gradient of the EBG structure, which is generated by the combination of two dielectric substrates with different dielectric constants and thicknesses. The calculated results indicate that the antenna possesses a relative 3dB gain bandwidth of 26%, from 13.6GHz to 17.7GHz, with a peak gain of 15dBi, which can well cover the whole impedance bandwidth for the reflection coefficient (S₁₁) less than -10dB, from 13.9GHz to 17.7GHz. The design method developed here is significantly effective, and can be easily adopted for antenna designs at other frequencies.