Flyswatter Shaped Antenna for 8 Element Beam Forming Network utilizing Butler Matrix

Abstract

This work brings an innovative design of a flyswatter shaped antenna for an 8-element linear array with Butler Matrix (BM) as the beamforming network and also proposes four port cross-over. The proposed flyswatter shaped antenna resonates at a frequency of 2.4 GHz. The results of all components (such as quadrature couplers, crossovers, phase shifters) used to realize the design of beam forming network are presented. The proposed cross-over has insertion loss close to 2dB. The 8-element linear array is integrated on FR-4 substrate $\left(\varepsilon_{\mathrm{r}}=4.3 \quad \text { and } \quad \text { height }=1.6 \quad \mathrm{~mm}\right)$ with BM based beamforming network to produces eight different beams at $-55^{\circ},-36,-21^{\circ},-7^{\circ}, 55^{\circ}, 36,21^{\circ}$, and 7°. The reflection coefficients and isolation at respective ports are less than -15 dB at the operating frequency and side lobes of radiation pattern are sufficiently low. This technique finds applications in IEEE 802.11 WLAN, lower frequency bands of 5 G and LTE, and wearable devices.