A wideband compact horizontally polarized omnidirectional antenna for 2G/3G/LTE

Abstract

A compact horizontally polarized omnidirectional slot antenna with a wide working band is presented in this article. The proposed antenna consists of 4 shorter driven cross‐shaped slots, 4 longer parasitic cross‐shaped slots, and a feeding network. Four shorter slots, placed on the same side of a circular substrate, are fed by a feeding network printed on the other side with uniform phase and magnitude. To enhance the bandwidth of the antenna, 4 longer cross‐shaped slots are inserted between adjacent longer slots to produce an additional resonant frequency. All 8 slot radiators placed symmetrically along the circumference results in an omnidirectional horizontal polarized radiation pattern. By utilizing cross‐shaped slots, a compact size of 0.53λL × 0.53λL × 0.005λL (λL is the free space wavelength at the lowest operational frequency) is achieved. The prototype of the proposed antenna is fabricated and measured. The measured results reasonably agree with the simulated results. The measured working band for |S11|<–10dB is from 1.62 to 2.81 GHz which successfully covers the 1.7 to 2.7 GHz 2G/3G/LTE bands. The measured gain variation in azimuthal angle is <1.7 dB within 1.7 to 2.7 GHz, and the cross polarization level is <–27 dB in the horizontal plane.

A wide‐band all‐metal and high‐gain omnidirectional antenna with simple prototype

“…Compared with the magneto‐electric dipole antennas, 15,16 both of them have a bigger volume size than our proposed antenna, and they do not have a omnidirectional radiation. Compared with References 17,18 our design has a wider bandwidth, higher gain, and an easy fabrication.…”

“…Besides, several magneto‐electric dipole antennas 15,16 were designed to achieve a wide‐band operation bandwidth, but the omnidirectional performance is lost. For horizontally polarized omnidirectional antenna, 17,18 a compact slot antenna 17 and a circular array formed by four composite dipoles 18 achieve the wide‐band performance. However, the bandwidth and the omnidirectional gain of References 17, 18 is not enough.…”

“…For horizontally polarized omnidirectional antenna, 17,18 a compact slot antenna 17 and a circular array formed by four composite dipoles 18 achieve the wide‐band performance. However, the bandwidth and the omnidirectional gain of References 17, 18 is not enough. Therefore, for the omnidirectional antenna, there are few researches to achieve the performance of broadband and relatively high gain at the same time.…”