Broadband and multiple frequency piezoelectric antennas based on mode coupling

To solve the limitation of narrow bandwidth, a piezoelectric antenna (PA) structure with enhanced bandwidth and multiple frequency points is proposed in this paper. The structure adopts electrode zoning design, and three resonators are formed on a piezoelectric material. The parallel connection of three resonators enhances the bandwidth of the PA, and the coupling between different vibration modes can respond to multiple frequencies, which significantly expands the resonant frequency of the PA. The simulation results show that the proposed PA has five effective resonant frequencies, and the fractional bandwidth of the radiated electric field can reach up to 4.3%. Compared with traditional PA with fully covered electrode, the radiated electric field intensity of the proposed antenna is increased by 26dB. These results verify that the proposed antenna has great potential in the application of portable, miniaturized, and high-performance wireless communication equipment.