Analytic Method for an FSS-Sandwiched Dual-Band Reflectarray Antenna

Abstract

This paper presents an analytical method for designing a high-efficiency frequency selective surface FSS-sandwiched dual-band circularly polarized reflectarray antenna. Results are obtained using Computer Simulation Technology Microwave Studio (CST MWS). The antenna is designed to operate within the receiving (19.6-21.2 GHz) and transmitting (29.4-31 GHz) bands while sharing the same unit and aperture. A double-layer FSS is loaded between the upper and lower antennas to suppress mutual coupling. An analytical approximation method using conformal mapping to determine the effective permittivity (ε r,eff) is observed. The transmission and reflection coefficients of the proposed FSS are synthesized using the transmission line approach. The comprehensive analyzed results obtained are compared with results obtained from simulations performed in CST MWS. To validate the performance of the proposed FSS-backed element configuration, a 20/30-GHz dual-band circularly polarized reflectarray with a 90-mm aperture is designed. The simulated gains are 23.3 dBi at 20 GHz and 27.7 dBi at 30 GHz with aperture efficiencies exceeding 47.25% and 57.85% in the receiving and transmitting bands, respectively.

A broadband single‐layer reflectarray antenna with split ring element

“…However, reflectarray antennas with moderate aperture size typically have a narrow gain bandwidth due to the narrowband nature of the elements. 2 To improve the bandwidth of the element, some design methods were proposed, such as multilayer structure, 3,4 phase delay line structure, [5][6][7] multiresonant structure, and so on. Among them, multiresonant structure is easy to affect the reflection performance of the unit cell by changing the resonance number, which makes it widespread application.…”

Dual polarized reflectarray antenna for operation in X and Ku bands

“…[3][4][5][6][7][8][9] On the other hand, a stacked configuration is used where each layer works at different frequencies. [10][11][12][13][14] For the first case, the mutual coupling of different resonant elements affects the antenna performance due to the limited space, which increases the complexity of the design. For example, a novel element composed of I-shaped dipole and circular ring was presented in Qu et al, 4 which operated at two closely separated bands with same polarization.…”

“…On one hand, various resonant elements are printed on a single‐layer substrate 3–9 . On the other hand, a stacked configuration is used where each layer works at different frequencies 10–14 . For the first case, the mutual coupling of different resonant elements affects the antenna performance due to the limited space, which increases the complexity of the design.…”

“…Using an FSS as band separator at the middle of double‐layer elements is the third case. A double layer FSS consisted of square loop was used between the higher and the lower element to suppress mutual coupling was introduced in Xi et al 12 Unfortunately, the thickness of the antenna and loss would be increased with a larger number of layers due to the additional separator for kind of method.…”

Design of a wideband bowtie‐shaped reflectarray antenna loaded with parasitic split rings

“…However, for small and medium size reflectarrays, the narrow bandwidth caused by the inherent narrowband performance of microstrip elements, which limits its practical applications 1 . Kinds of meaningful efforts have been adopted to design wideband elements, such as using sub‐wavelength components, 2–4 phase delay lines, 5–7 or multilayer substrates 8 . Besides, additional resonances can be introduced by adopting multi‐resonances elements, which is a simple and effective method to achieve phase linearity and range requirement 9–13 …”