Dual-Band Microstrip Circular Patch Antenna With Monopolar Radiation Pattern

• Published in: IEEE antennas and wireless propagation letters Vol. 15; pp. 1004 - 1007
• Main Authors: Dai, Xi-Wang, Zhou, Tao, Cui, Guan-Feng
• Format: Journal Article
• Language: English
• Published: New York IEEE 2016; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Antenna measurements; Antenna radiation patterns; Dual band; low profile; microstrip antenna; Microstrip antennas; monopolar antenna; mushroom structure; Patch antennas; Resonant frequency
• ISSN: 1536-1225; 1548-5757
• DOI: 10.1109/LAWP.2015.2490079

A novel dual-band microstrip monopolar patch antenna with zeroth-order resonance is proposed and analyzed in this letter. The antenna is a combination of circular patch antenna with center-fed and circularly periodic mushroom units. With the zeroth-order resonant (ZOR) mode and TM 02 mode, the proposed antenna can create horizontal magnetic loop currents on the patch, which lead to a low profile of 0.02λ at the low frequency band. The radiation mechanism of the proposed antenna is discussed. The antenna is fabricated on a double-layered printed circuit board (PCB) and center-fed by a 50- Ω SMA connector. Simulated and measured results show that the proposed antenna produces a stable monopole-like radiation pattern in two working frequency bands. The corresponding impedance bandwidths and gains are 0.75% and 5.1 dBi for the low frequency band and 20% and a range of 5.8-8 dBi for the high frequency band.