A Novel Design of Microstrip Arrays for Relay-Based Wireless Network

Abstract

A relay station (RS) is a smart transceiver used under a 4G wireless network in order to extend network's coverage and capacity. It uses an antenna system that includes an antenna for connecting the relay with the end users (access link) and the RS with the base station (backhaul link). In this paper, a 7.9 dBi access and 11.4 dBi backhaul antennas are presented for the frequency range of 3.3 to 3.8 GHz. The antennas are simulated and fabricated, and relevant measured results in terms of return loss and radiation pattern are presented and analyzed. Considering that the planes of those two antennas are positioned in an angle (omega), two antenna configuration geometries are tested in terms of coupling. The experimental results of for several values of the angle show that the interaction between the radiating elements is dependent on their relative position. Simulated and experimental results are in good agreement, showing coupling typically less than −40 dB. A comparison in terms of coupling between the proposed antennas and commercial ones proves that the suggested antennas provide 10 dB lower coupling.

Coupling Measurements of an Antenna System Suitable for Relay-Aided Wimax Network

“…[18] for completely different antennas. In reference, the tested antennas utilize one substrate FR-4 and the array includes a power division circuit.…”

“…For this reason it is useful to examine the coupling between the antennas. Coupling comparison between antennas of [18] and the modified E-shaped ones is denoted in Table 3, were S 21 in the case of the modified E-shaped antennas is enhanced as a result of the lower distance d. In configuration 1 the coupling presented in this study is enhanced compared to the corresponding measurements of [18] while configuration 2 provides approximately the same value of S 21 for 90 • but coupling of the modified E-shaped antennas for 180 • is significantly increased. Although coupling measurements of the proposed antennas are increased compared to [18], S 21 is at a sufficiently low level below −28.5 dB and the presented antennas have increased gain and bandwidth therefore their utilization is beneficial and advantageous.…”

Miniaturization Design for 8 × 8 Butler Matrix Based on Back-to-Back Bilayer Microstrip

“…Microstrip technology is widely used for implementation of antenna arrays [8,9], feeding networks [10] such as Butler matrices [11,12], because it has advantage of low cost, low profile, and convenience for manufacture. However, 8 × 8 or higher order microstrip-line matrices have seldom been reported due to their complexity, increased dissipation, and difficulty in design [13].…”