Design, analysis, and modeling of miniaturized multi-band patch arrays using mushroom-type electromagnetic band gap structures

Novel designs of miniaturized multi-band 1 3 2 patch antenna array with electromagnetic band gap (EBG) for wideband operation are presented in this article. The proposed patch array is composed of three unequal arms fed by CPW-to-slotline transitions to widen the impedance bandwidth with multiple resonances. By adding two conventional mushroom-type EBG (CMT-EBG) structures on both sides of 100 Omega slotline transitions, the compact wideband patch array (first design) is obtained. This proposed design with CMT-EBG includes two bands with the measured ranges (S-11 <= -10 dB) of 6.65-6.95 GHz (C-band) and 8.57-11.53 GHz (X-band). Moreover, the proposed 1 x 2 patch array with the 3 x 3 CMT-EBG array on the one side of the structure (second design) operates at multi-bands with the measured -10 dB impedance bandwidths of 5.80-5.98 GHz, 6.25-6.47 GHz, and 8.48-11.52 GHz. The second design compared to the first design introduces a considerable size reduction with more resonance tuning capability. The performance of the proposed designs is analyzed based on the EBG band gap properties near the slotline transitions. These designs with the EBGs indicate prominent features like resonance tuning capability, acceptable miniaturization, and enhanced impedance bandwidth with low-fabrication cost. In this study, an equivalent circuit model of the proposed first design with EBG is also offered to describe the properties of multi-band operation.