Comparative effects of capacitive and inductive superstrates on the RCA's gain

Abstract

The radiation performance of the resonant cavity antenna (RCA) is mainly determined by the superstrate, and thereby various superstrates are designed for the RCA to obtain high performance. In this work, the comparative effects of the capacitive and inductive superstrates on the RCA's gain are investigated systematically. Three approaches including the leaky‐wave model, full‐wave simulations and prototype measurements are employed for the investigation. Using the leaky‐wave model, the gains of the RCA with various superstrates are calculated and a difference between the gains with the capacitive and inductive superstrates is observed. Full‐wave simulations and prototype measurements further prove the result. All the approaches demonstrate that the capacitive superstrate has the potential to obtain a higher gain, in comparison with the inductive superstrate having the same reflection magnitude and aperture size.

Beam-Reconfigurable Antenna with Inductive Partially Reflective Surface and Parasitic Elements

“…PRSs have been classified into two types according to the equivalent reactance of their periodic structures: capacitive PRS with reactance less than 0, and inductive PRS with reactance larger than 0 [32]. The two PRS types have different effects on PRS antenna properties, e.g., the capacitive PRS is more suitable for broadside beam, as it facilitates higher gain [30], [33].…”

Dual-Band Shared-Aperture Antenna with Single-Layer Partially Reflecting Surface

“…As the frequency increases from f 0  Δf to f 0 + Δf, the equivalent reactance increases monotonically from a negative to a positive value, whereas the reflection phase of the PRS decreases monotonically from π + Δφ r to π -Δφ r (Δf and Δφ r are small and positive values). The PRS is changed from being a capacitive one to an inductive one with the frequency variation, according to the sign of the equivalent reactance [27]. Therefore, the reflection phase of the capacitive PRS unit cell is larger than π, whereas that of the inductive PRS unit cell is less than π near the resonance frequency with maximum reflection.…”

“…Unlike the traditional DS-FPC antenna with a shared dualband FPC, the proposed antenna integrates a FPC antenna and a short backfire antenna (SBA), which is a type of high gain antenna with a typical profile of 0.5 free-space wavelength (0.5) [28]. The single-layer PRS is designed to be capacitive, to achieve a higher gain for the FPC antenna [27]. In addition, the PRS height calculated from (1) for the capacitive PRS is larger than 0.5, so the FPC antenna is designed for HB, such that the shared PRS height can still be close to the typical SBA profile of 0.5 in LB.…”