Radiation Pattern Prediction for Third‐Order Intermodulation of the Reconfigurable Reflectarray Antenna With Embedded Varactor

The irregularly located element array within the antenna aperture can be applied to obtain narrow main lobe width and low sidelobe levels with fewer elements as compared with the traditional (periodic) array configurations. In this article, a reconfigurable reflectarray antenna (RRA) combined with hyperuniform disordered distribution is presented. Based on the theoretical radiation pattern of reflectarray, it has been found that the proposed array with reduced elements holds a similar radiation pattern as that of a corresponding periodic array. Meanwhile, the reflectarray avoids the design of complicated feeding network for the disordered phased array antenna. In addition, for a reconfigurable reflectarray to achieve beam scanning, active devices are necessary. In such case, the design of RRA with fewer elements is of particular importance. A 1 bit RRA of 64 elements prototype has been designed, fabricated, and measured. The side length of each element is <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.625\lambda $ </tex-math></inline-formula> . Experimental results agree well with the full-wave simulations, and scan beams within ± 50° range have been obtained with a peak gain of 17.4 dBi at 12.5 GHz.

In this article, we propose an ultralow-power-consumption reconfigurable reflectarray antenna (RRA) capable of wide-angle beam scanning and simultaneous phase, amplitude, and polarization control. The RRA element is integrated with two single-pole single-throw (SPST) switch chips, which achieve 1-bit phase shift and continuous amplitude control for both <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</i>- and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</i>-polarizations. By independently biasing each element, the RRA enables wide-angle electronic beam scanning in both polarization channels. Flexible beam phase control is achieved by adjusting the reference phase in the array factor. The beam amplitude is continuously tuned by precisely controlling the bias voltages of the integrated SPST switch chips. Furthermore, since both the phase and amplitude of the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</i>- and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</i>-polarizations can be modulated, the RRA can synthesize scanning beams with arbitrary polarization. As a demonstration, a 16 × 16 RRA prototype is designed, simulated, and measured. Both simulations and measurements confirm that the RRA can achieve beam scanning over a wide-angle range of ±60°, with a maximum gain of 20.78 dBi and an aperture efficiency of 22.8%. Additionally, its capacities for phase, amplitude, and polarization control are fully demonstrated. Furthermore, the measured maximum power consumption of the RRA is only 0.34 W, corresponding to 1.3 mW per element. With its ultralow power consumption and versatility, the proposed RRA shows great potential for green wireless communications and advanced radar applications.

A folded reconfigurable reflectarray antenna for mono-pulse radar application is presented in this paper. The proposed antenna combines the properties of reconfigurable reflect-array antenna and folded reflectarray antenna. A reconfigurable reflectarray with $15\times 15$ elements is developed to verify the design method. The antenna design is calculated and simulated using MATLAB and HFSS, and detailed results are presented and discussed. The reconfigurable reflectarray antenna can operate at Ku-band and provide the performance of beam scanning. This reconfigurable reflectarray antenna has significant potential for satellite applications, due to its low profile, simple control and beam-scanning capability.

An electronically steerable monopulse antenna based on reconfigurable reflectarray antenna (RRA) has been designed, fabricated and tested. The large-scale RRA at X-band is consisted of $160\times 64$ elements integrated with PIN diodes, and is controlled by arrays of 160 field-programmable gate arrays (FPGAs) in parallel, for the steerable monopulse patterns. The steerable sum-difference beams are achieved by the diode state distributions of the RRA. The gain of the RRA is measured to be 37.35dBi, and the null-depth is measured to be -43.51dB at the direction angle of 0 o. A null-depth of under -37.54dB is verified at the direction angle of 60°. The electronically steerable monopulse antenna based on RRA presents a low-cost solution for high resolution tracking applications.

A liquid metal based 1-bit reconfigurable reflectarray antenna for beam-scanning applications

In this article, a metal-only reconfigurable reflectarray antenna (RRA) is proposed for generation of diversified circular-polarization (CP) focused beams and mode-agile vortex beams in the X-band. The proposed RRA element has the 3-D metal-only configuration, which consists of three staircases with different heights, a turntable, a latch, and a base. By rotating the proposed RRA element in 45° steps, the ability of 1-bit phase quantization with orthogonal linear polarization (LP) reconfigurability can be realized. Then, a 26 × 26-elements reconfigurable reflectarray antenna feeding by a linear polarization horn antenna is designed to enable free conversion of line-to-circle polarization at the array level. Full-wave simulations show that the diversified circular-polarization beams can be synthesized by adjusting the aperture element distribution. Furthermore, a manually reconfigurable reflectarray antenna prototype is fabricated to obtain the actual performance of the synthetic LHCP focused beams. The measured maximum gain of the LHCP beams is 27.1 dBi, with the aperture efficiency of 24.2% where the beam point at 20°, and the 1-dB gain bandwidth is 18.0% (9.3 GHz − 11.1 GHz). Finally, mode-agile vortex beams can also be realized by using the proposed reconfigurable reflectarray antenna, and the simulated results show that the mode purity of vortex beams are all above 35% in different modes, and the maximum gain of the vortex beams is 21.1 dBi, with aperture efficiency of 6.1% where the mode of vortex beams is −1.

An origami-based foldable and reconfigurable Reflectarray Antenna (RA) with multiple apertures is proposed for CubeSat applications. The proposed configuration consists of a central RA embedded in folding panels using Lamina Emergent Torsional (LET) joints based on compliant mechanisms. Depending on the folding direction of these panels (forward or backward), a new RA aperture is formed. The proposed RA along with its folding panels and hinges is fabricated using only a single PCB. A prototype of such an RA with two foldable panels is fabricated and measured. This RA operates in the Ku-band at 16 GHz and provides two pencil beams pointing at (8 = 30°, φ = 0°) and (8 = -30°, φ = 0°), and a dual-beam pointing at (8 = +27°, φ = 0°) and (8 = -29°, φ = 0°). The proposed RA provides a gain of 25 dB and 19 dB in its singleand dual-beam operations, respectively. For CubeSat applications, the key advantages of this RA are its small stowed volume, reconfigurable EM performance, beamsteering capabilities, monolithic construction, low fabrication cost, and reduced complexity.

Terahertz reconfigurable reflectarray antennas (RRAs) hold significant promise for next-generation wireless communication systems by enabling dynamic beam control to mitigate severe path loss at high frequencies. This work presents a Complementary Metal-Oxide-Semiconductor (CMOS)-based RRA for terahertz amplitude control using tunable split-ring resonators. First, a terahertz switch in standard 65 nm CMOS process is designed, tested, and calibrated on the chip to extract the equivalent impedance, enabling precise RRA element design. Next, a reconfigurable element architecture is presented through the co-design of a split-ring radiator, control line, and a single switch. Experimental characterization demonstrates that the fabricated RRA achieves 3 dB amplitude variation at 0.290 THz with &lt;8.5 dB element loss under 0.8 V gate bias. The measured results validate that the proposed single-switch topology effectively balances reconfigurability and loss performance in the terahertz regime. The demonstrated CMOS-compatible RRA provides a scalable solution for real-time beamforming in terahertz communication systems.

Microstrip reconfigurable reflectarray antennas (RRAs) have great potential for advanced systems including satellite communications and the 6th generation (6G) wireless mobile communication networks. However, as a type of microstrip antennas, RRAs generally exhibit an intrinsic issue of narrow bandwidths. This issue is further deteriorated by complicated structures for phase shifting and DC supplying in RRAs. PIN diodes have been used in recent works to control the phases of RRA elements. However, modelling them is still costly and time consuming. In this work, a simple but novel method for modelling PIN diode SMP-1340-040 is developed by using waveguides and modified simulation approaches. Based on the obtained model, a broadband 1-bit unit cell using only one substrate is also proposed, and it achieves a simulated bandwidth of 40.6% and 33.8% for linear and circular polarizations, respectively. The experimental results show an excellent agreement with the simulation, which confirms the accuracy of the proposed PIN diode model. Moreover, the performances of the unit cell demonstrate that it can be used for designing RRAs in bands X and Ku.

Terahertz (THz) high gain antennas with electronic beam-scanning capability have been long required in various modern applications. In this paper, a novel reconfigurable reflectarray antenna (RRA) at 0.3 THz with 16×16 individually controlled 1-bit phasing elements is proposed. The element consists of a shorted bow-tie microstrip patch and a double-channel heterostructure HEMT in the middle. Electronic 1-bit phase control can be achieved by switching the state of HEMT. The element simulation verifies its wideband and low cross-polarization performance. Design and analysis of a RRA with 16×16 elements and practical biasing circuits are presented. The high gain beam scanning capability of the proposed RRA is validated by theoretical calculations.

In this paper, an electronically 1‐bit reconfigurable reflectarray antenna (RRA) with wide‐angle beam‐scanning and high efficiency performance is presented for formation satellite communication applications. A 1‐bit phase distribution can be generated by controlling the state of the PIN dipole in the configurable element comprising a double split ring (DSR) patch and two T‐shaped parasitic structures. The resonant frequency of the DSR patch in both states can be optimised by a T‐shaped parasitic structure, which is beneficial to improving the bandwidth and aperture efficiency. A 180° ± 20° phase difference can be realised from 9.7 to 10.3 GHz only by controlling one PIN dipole loaded on the proposed element, which ensures stable radiation performance over a larger band. To validate the effectiveness of the proposed element, a prototype RRA containing 20 × 20 units is designed and measured. A ±60° beam scanning range with the gain drop of 3.2 and 3.3 dB in the xoz and yoz planes is realised, which verifies the wide‐angle beam‐scanning ability of the RRA. The measured peak gain is 25 dBi at 10 GHz in the broadside direction, corresponding to an aperture efficiency of 25.2%. Meanwhile, the 1‐dB gain bandwidth of the proposed RRA is 12.6%.

In this paper, a wideband reconfigurable reflectarray antenna (RRA) using 1-bit resolution for beam scanning with two-dimensional (2D) capability is presented at Ku-band. A 1-bit RRA element with a rectangular patch embedded with slots is proposed for broadband operation. Each element is equipped with a single PIN diode, allowing for resonance tuning while ensuring low cost and minimal power consumption. According to the simulation results, the proposed element is capable of 1-bit phase resolution with a phase difference of ${180^\circ \pm 20^\circ}$ stability from 11.27 to 13.74 GHz, which corresponds to an approximate bandwidth of 19.75%. To demonstrate its capabilities, we developed, fabricated, and tested a wideband electronically RRA with ${14 \times 14}$ elements. The experimental results demonstrate that the realized maximum gain in the broadside direction is 21.1 dB with a peak aperture efficiency of 20.9%. 2D beam scanning within ${\pm50^\circ}$ angular range are obtained and the scan gain reduction is 1.88 dB for ${-50^\circ}$ scanned beam in E-plane while 2.21 dB for ${50^\circ}$ scanned beam in H-plane. The 1-dB gain bandwidth of the RRA is 15.1%.

In this letter, a 1-bit wide-angle and multi-polarization beam-scanning reconfigurable reflectarray antenna (RRA) is designed, fabricated and measured. The proposed RRA element consists of a square base, a circular turntable and three butterfly staircases with different heights based on 3D all-metal structure. The 1-bit reflected phase and orthogonal linear polarization reconfigurability can be achieved by rotating the proposed RRA element. Then, an all-metal RRA prototype with 26 × 26 rotational elements are fabricated, which is fed by a <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</i> -polarized corrugated horn with 20° inclination. The multi-polarization scanning beams are generated by dynamically rotating individual element on the aperture. The measured results show that the RRA prototype can achieve a 60° beam scanning with maximum scan loss of 3.3 dB in <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</i> -polarization, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</i> -polarization and circular polarization at 10.0 GHz. The peak gains of 27.2 dBi, 26.7 dBi and 27.1 dBi with aperture efficiency of 24.7%, 22.0% and 24.2% are obtained where the 1-dB gain bandwidth is 24.0%, 14% and 18% for <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</i> -polarization, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</i> -polarization and LHCP. The proposed RRA greatly reduces the cost, complexity and RF loss.

In this letter, a wideband high-efficiency 1-bit 16 × 16 reconfigurable reflectarray antenna (RRA) is proposed. First, a wideband and low loss 1-bit RRA element is designed. It consists of double-layer patches printed on two dielectric substrates, respectively, forming a multiresonant behavior to expand the bandwidth.Due to the relatively thin thickness of the double-layer dielectric substrate (0.05 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">λ</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> ), the element has low reflection loss. Therefore, the high efficiency and wide bandwidth performances can be obtained simultaneously. The phase difference between the two states of the RRA element is stable within 180 ± 20° in the frequency range of 12.9–16.5 GHz. Based on the broadband RRA element, a 16 × 16 RRA was fabricated and measured. Tested results show that the proposed RRA achieves 22.5% of 1 dB gain bandwidth and 25% of maximum aperture efficiency.

This work presents a pattern and polarization reconfigurable reflectarray antenna (RRA). Using 1-bit independently controlled dual-linearly polarized (DLP) units, the radiation beam of the RRA can be scanned with switchable polarization. The designed unit is composed of a crossed dipole, a metallic centered patch, four PIN diodes and biasing networks. By controlling the working states of the PIN diodes, the unit possesses independently 180° reflection phase shift in either of the two linear polarizations (LPs). A novel polarization manipulation method is introduced, and the 1-bit DLP unit can be transformed into a 2-bit unit with agile polarization. Based on the DLP unit, the proposed RRA can realize polarization reconfigurable among ±45° LPs, left-hand circular polarization (LHCP) and right-hand circular polarization (RHCP) by only changing the biasing voltages applied on the RRA. A prototype including 256 units is analyzed, fabricated, and measured. The 2-D beam-scanning ability is verified for dual-linear polarization and reconfigurable polarization. Good performance, including high gain and good polarization purity, can be observed. The proposed RRA features a wide beam scanning range and agile polarization, which makes it a good candidate for the wireless communication system.