Low-Profile Uni-Cavity High-Gain FPC Antenna Covering Entire Global 2.4 GHz and 5 GHz WiFi-Bands Using Uncorrelated Dual-Band PRS and Phase Compensation AMC

A design methodology of the dual-band Fabry-Perot-cavity (FPC) antenna is proposed, realizing dual-broadband high gain and keeping the simplicity of one low-profile resonant cavity. A ray optics model is applied to obtain the phase resonance condition for dual-band FPC antennas. The proposed antenna employs a tightly stratified partial-reflective-surface (PRS), an artificial-magnetic-conductor (AMC) ground, and a dual-band microstrip feed. The PRS modulates independently the dual-band reflection coefficient to maintain a large amplitude and a positive phase gradient. Meanwhile, an AMC ground is distinctively employed to compensate for the transmission phase difference of the lower band when the cavity height meets half the wavelength of the upper one, enabling eventually a low-profile uni-cavity. Furthermore, a dual-band microstrip feed with two asymmetric slots is customized as the primary radiator. Detailed electromagnetic studies are carried out to illustrate the operating mechanisms of these components. Finally, a proof-of-concept prototype is fabricated covering the entire global 2.4 and 5 GHz WiFi bands. The measurement results agree well with the simulation, and the 3 dB gain bandwidths of 7.2% and 16.2% with peak gains of 13.6 and 15.0 dBi over two wide bands of 2.42-2.60 and 5.1-6 GHz are achieved, respectively, with a single cavity height of 26.8 mm.