Design of miniaturised circular polarisation-reconfigurable and frequency agile slow-wave SIW based microstrip antenna for wireless applications

ABSTRACT

Maintaining acceptable radiation performance over the entire operation bandwidth is a significant challenge in development of a miniaturised reconfigurable antenna. To address this issue, a new Substrate Integrated Waveguide (SIW) based reconfigurable antenna using slow wave structure is presented in this study. The proposed SIW antenna is based on a layered construction with metallic blind vias connecting to ground plane of SIW. The multi-layer structure of SIW with blind vias helps to separate magnetic and electric fields in the SIW cavity. Thus, a slow wave effect is also utilised and it leads to 36% reduction in the antenna size as compared to conventional SIW cavity. To attain the polarisation and frequency reconfiguration, a cross slot is introduced in the top metallic layer of the SIW cavity and four PIN diodes are connected into the cross-slot arms. Experimental results exhibit frequency reconfigurability in different operating regions with resonant frequencies 4.35, 5, 5.8, 6.4, and 9.6 GHz. The polarisation reconfigurability of the proposed antenna is achieved at 5 GHz with LP/RHCP/LHCP. The proposed antenna exhibits 3-dB axial ratio bandwidth of 4.8 to 5.2 GHz with peak gain of 4.2 dBi.

KEYWORDS:

• Compact
• SIW
• slow-wave
• frequency reconfiguration
• polarization reconfiguration

Disclosure statement

No potential conflict of interest was reported by the authors.