Design and analysis of a novel miniaturized dual-band omnidirectional antenna for wifi applications

—In this article, a novel dual-band omnidirectional antenna for WiFi applications is presented and investigated. The proposed antenna is mainly composed of two pairs of half-wavelength dipoles with different lengths. It is fed by a microstrip balun, which provides a good impedance matching for desired dual-band operation. The dimension of the proposed antenna is only 50 mm × 10 mm × 1mm (0.4λ0 × 0.08λ0 × 0.008λ0,andλ0 is the wavelength of 2.4 GHz). The performance study of this dualband omnidirectional antenna with different geometric parameters has been conducted. The final design is fabricated and measured, and the results exhibit a good impedance bandwidth of approximately 19.2% for |S11| ≤ −10 dB ranging from 2.24 to 2.70 GHz centered at 2.4 GHz, and over 17.4% for |S11 |≤−10 dB ranging from 4.73 to 5.6 GHz centered at 5.0 GHz. This antenna also has a stable gain of 2.09 ∼ 2.87 dBi and omnidirectional radiation patterns over the whole operating band. Dual-band coverage, stable omnidirectional radiation performance, simple structure, and miniaturized dimension make this antenna an excellent candidate for WiFi applications. © 2020, Electromagnetics Academy. All rights reserved.