CP Antenna Array With Switching-Beam Capability Using Electromagnetic Periodic Structures for 5G Applications

Abstract

This paper proposes a novel circularly polarized electromagnetic band-gap (EBG) antenna array backed by an artificial magnetic conductor (AMC) that operates in the 26-32-GHz bands. The designed antenna is a 2 × 2 Yagi-Uda antenna array that uses the directors' semicircles to direct the radiation in the horizontal end-fire direction. The feeding of the array is designed with two parallel T-junction portions forming a parallel feeding network that converts the polarization from linear to circular. An AMC is placed underneath the antenna to suppress the backward radiation and obtain the propagation only in the +z plane. The novel approach is based on the fact that EBGs are placed around the array to give to the antenna, beamswitching capability. This simple technique provides a high beam tilting angle of +90 • from the end-fire to the full broadside plane. The final EBG-AMC-antenna array is circularly polarized and presents, at 29 GHz, a gain of 11.9 dBi, and an axial ratio bandwidth of 10% from 28 to 31 GHz. By assessing the high antenna performances presented in this paper, and the high angle beam-switching capability by adding the EBG, the novel array could be seen as a potential candidate for implementation in future 5G applications. INDEX TERMS Antenna array, artificial magnetic conductor (AMC), circular polarization, EBG structures, millimeter wave antennas, multi-feeding, periodic structures.

An Indoor Channel Model for High Data-Rate Communications in D-Band

“…In these scenarios beamforming approaches [38], [39] should be able to exploit secondary MPCs which are not obstructed. Thus, given the high losses and potential obstructions in this band, high gain beamforming antennas would be required.…”

Metasurface-Based Single-Layer Wideband Circularly Polarized MIMO Antenna for 5G Millimeter-Wave Systems

“…The antennas reported in [34][35][36] offer the advantages of a single printed layer and CP radiations but have the disadvantages of limited AR bandwidths and the absence of MIMO functionality as well as low gain even though these designs are at microwave frequencies. It is worth mentioning that among the 5G antennas with MIMO capabilities [44][45][46][47][48][49][50][51], only [48][49][50] have CP polarization. The antennas with superstrate [48][49] offer the advantages of MIMO, wide bandwidth, and high gain (<14 dBic) have the critical disadvantages of design complexity because of the multiple printed layers and the presence of air gap.…”

“…The CP MIMO antenna presented in [50], has a low gain of 8 dBic while the CP bandwidth is restricted to only 3%. The 5G CP antennas presented in [26,[51][52][53][54] are missing MIMO features besides of limited operating bandwidths. Although [26] and [53] are offering wider operating bandwidths but have drawbacks of multiple printed layers.…”

Beamformer development challenges for 5G and beyond

“…Another way of beamforming in the fixed antenna array case is by using electromagnetic-bandgap-(EBG) backed structures. One example is provided in [77] where an EBG-backed structure is operating from 26 to 32 GHz. An example of a fixed beamformer that can be mounted onto a ceiling and is designed using tapered slot antennas is given in [78].…”

“…The study shows an addition calibration after computing the path loss and updated version has beamscanning capability of 45 with a higher gain of 12 dB i. A stacking topology is shown in [77] that uses the principles of artificial magnetic conductor and helps in the pattern diversity and antenna gain of 11.9 dB i. A planar Yagi-Uda antenna uses two parallel T-junctions form parallel antenna feeding resulting in circular polarization.…”