An Improvement Approach for Wide-Angle Impedance Matching Using ELC Metasurface Slabs for SIW Slot Array Antennas

Abstract

The effects of mutual coupling in beam scanning arrays increase degradation in gain as the beam is scanned off the broadside. A simple and effective approach for a deployed SIW slot array antenna through the use of artificially structured materials is proposed to improve its performance of wide-angle scanning in the E-plane. Metasurface slabs of one-tenth wavelength electric-inductive-capacitive (ELC) resonators are vertically placed halfway between the adjacent waveguides without changing the antenna structure to realize wide-angle impedance matching (WAIM). The ELC metasurface is designed to operate at a linear region rather than at a resonance region to use its transmission property for greatly weakening mutual couplings. Inserting metasurface slabs between two adjacent waveguides to reduce the mutual coupling can achieve impedance matching at large scan angles. A 10 × 10 SIW slot array operating at X-band is modelled and simulated to study how the vertically placed ELC metasurface slabs over the antenna affect the array's beam scanning performance. The simulated results show that the scan range of the antenna is extended from −50°to 50°to −70°to 70°under the criteria that radiating efficiency is greater than 80%.

Use of Subarrays in Linear Array for Improving Wide Angular Scanning Performance

“…Ensuring wide-angle scanning in phased arrays has long been known to be an exacting task, as demonstrated by early works such as [2]- [4]. More recently, studies have dealt primarily with the effects of mutual coupling [5]- [17] and scan-loss [18]- [23].…”

Wideband and High-Efficiency SIW Cavity-Backed Magneto-Electric Dipole Antenna Array

“…SIW inherits the merits from both microstrip lines and metal waveguides and has the advantages of low transmission loss, low fabrication costs, ease of integration, and so on. erefore, it has been widely used in antenna arrays [22][23][24][25][26][27][28][29][30][31][32][33]. Series feeding networks based on SIW have lower transmission loss and excellent radiation performance.…”

“…Series feeding networks based on SIW have lower transmission loss and excellent radiation performance. However, large antenna arrays with series feeding networks suffer from narrow bandwidth [23][24][25].…”