A X/Ku dual‐band reflectarray design with cosecant squared shaped beam

Abstract

low band, the left-handed transmission line is not very required. The measured isolation between the two pass bands is >54 dB at the low band and >41 dB at the high band.As shown in Figure 5, the quadplexer has the measured insertion losses at the low band (882-960 MHz) less than 3.0 dB. For high band (1.85-1.99 GHz), the insertion losses are less than 3.0 dB. The measured return losses are less than 10 dB at all the pass bands of the quadplexer. The isolation between the low and high bands is >60 dB, which is higher than that of the diplexer since the duplexers isolate between the bands further. CONCLUSIONThis letter presents a low-loss lowpass-highpass diplexer and quadplexer. A simple 50-X transmission line at the lowpass filter side maximizes the lowpass channel impedance at the highpass frequency band, resulting in low loss and high isolation (>54 dB). To minimize the diplexer size, high impedance meander lines and stepped impedance transmission lines are used. The measured and full-wave EM simulated results of the diplexer show a good agreement and the quadplexer has a designed transmission performances in all four low and high pass bands. ABSTRACT: A X/Ku dual-band center-fed microstrip reflectarray antenna with cosecant squared shaped beams has been developed. The circular reflectarray has a radius of 0.3 m and a flat aperture that emulates a cylindrical reflector antenna. The reflectarray is designed for two frequency bands: 10 GHz (X band) and 15 GHz (Ku band). Crossdipole elements and double-ring elements are uniquely applied on a dual-layer structure to achieve the desirable dual-band operations. As the two operation frequency bands are close to each other, the coupling effects of the dual-band reflectarray elements are investigated, and the unit cell design is optimized in simulations to suppress the interband interference. A phase-only synthesis technique for cosecant squared patterns is also discussed and realized. For demonstration purpose, prototype antenna is fabricated and measured and the measured results are compared with the simulation results.

Optimum design of dual band shaped-beam circularly polarized reflectarray antenna based on physical optic method

“…The elevation and azimuth patterns are considered the XZ plane and YZ plane in the Cartesian coordinates, respectively. Similar works have been recently done and reported in literatures [31][32][33][34][35]. It can be said that in all these referenced works, suboptimal performance is achieved.…”

“…Shaped‐beam antennas could potentially be used for SATCOM applications where it is necessary to illuminate the special geographical region. In addition, high‐gain antennas (more commonly RA antennas) with single or dual‐band operation and cosecant squared radiation patterns are widely used in radar application (i.e., ground‐based sense and avoid radars and/or coastal surveillance radars) .…”

A Single-Layer Dual-Band Reflectarray Cell for 5G Communication Systems

“…Negligible mutual effects between the two bands are demonstrated, thus achieving an independent phase-tuning mechanism for each frequency band, by properly changing the fractal shapes. Unlike other multiband reflectarray cells presented in the literature [17][18][19][20][21], the proposed dual-band fractal cell allows to achieve the following: a simpler and thinner structure with respect to the multilayer stacked configurations [17,18]; smaller unit cell size at both operating frequencies (≅0.4λ at 28 GHz, ≅0.54λ at 38 GHz) with respect to other single-layer configurations [19,20], thus preserving the capability to point the main beam at large scan angles, without occurring in grating lobe phenomena; and smaller electrical interferences between the elements operating at the different bands [21], despite the adopted small interelement spacing.…”

Dual-Band Capabilities Of The Fourth Order Phoenix Cell for Reflectarrays Antennas

“…In space applications, the environment constraints usually favour single-layer technology, which makes dual-band operation even more challenging to develop. Several single-layer designs with dual-band capabilities have been reported using either an interleaved array configuration [3] or a multi-band unit-cell [4]. As a possible candidate in this last category, Phoenix Cell (PC) with its rebirth capabilities and numerous geometrical degrees of freedom offers undeniable advantages for wide-band operation and layout smoothness [5].…”