Ultralow-Power-Consumption Reconfigurable Reflectarray Antenna for Beam Scanning and Phase, Amplitude, and Polarization Control

This letter proposes a novel element-level amplitude and phase control method to achieve a millimeter-wave wide-angle beam-scanning phased array with low sidelobe. A beam-steerable antenna element is realized by feeding a pair of shorted patches with two separate ports. The main novelty is that the main-beam direction and radiation-null position of the proposed antenna pair can be tuned by controlling the excitation phase and amplitude of two ports, respectively. No active RF switch or varactor with DC biasing circuit is required. Furthermore, a millimeter-wave phased array is made up using proposed beam-steerable antenna pairs. By controlling the element-level amplitude and phase together with the array factor, the beam-scanning angle of the array is enhanced, and the sidelobe level is simultaneously suppressed in the process of beam scanning. The proposed array achieves a high peak gain of 13.1 dBi and a wide scanning range of ±70°, maintaining a low sidelobe level of smaller than -10 dB in the frequency band of 26-30 GHz. Compared with previous related works, the advantage of the proposed array lies in high gain, simple structure, wide-angle beam scanning capability and good sidelobe suppression.

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.

A G-Band single pole single throw (SPST) switch for low insertion loss and high isolation is proposed and fabricated using 65-nm CMOS technology. A grounded co-planar wave guide (GCPW) folded coupled line topology is developed to improve the switch isolation and lower its insertion loss simultaneously. Based on this topology, this switch achieves minimum 2.4-dB insertion loss (IL) in G-Band with minimum 28.5-dB isolation (ISO). This switch consumes only 0.0067 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> chip area. To the authors' knowledge, this CMOS SPST switch achieves the best performance among the published switches in bulk CMOS processes at this frequency.

In this letter, a broadband and low loss circularly polarized (CP) electronically reconfigurable reflectarray antenna (RRA) that can operate over the X-band is reported. The proposed RRA invokes a new reconfigurable magneto-electric (ME) dipole based element for dynamically manipulating the phase of the back-scattered CP wave from each pixel, and hence, the direction of the reflected beam. The engineered wideband ME-dipole element and the design of a low loss reconfigurable perturbation structure contribute jointly to a superior CP bandwidth as well as a high efficiency. A reflectarray prototype with two-dimensional (2-D) beam scanning is designed, fabricated, and measured, demonstrating a wide-angle beam scanning capability. Besides, notable advances in bandwidth and aperture efficiency of the 1-bit CP RRA are identified, over the previous state of the art.

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.

This letter presents novel high power and reliable radio frequency (RF) microelectromechanical systems switches with single-pole single-throw (SPST) and single-pole triple-throw (SP3T) configurations. An in-plane movable structure with a single layer is made using a simple standard silicon-on-insulator process, which greatly reduces the micro-fabrication complexity and cost compared with the previously reported multi-contact switches with out-of-plane movable structures. The SPST switch achieves a uniform current distribution through each contact, thereby increasing the power handling capability of the switch. The SP3T switch is a derivative of the SPST switch with separate individual actuations. The experimental results demonstrate that the fabricated switches have superior RF performances: insertion losses are −0.9 and −1.3 dB at 6 GHz for SPST and SP3T switches, respectively, whereas isolations are better than −29 and −37 dB from dc to 6 GHz for SPST and SP3T switches, respectively. In hot-switching conditions, the SPST switch can handle RF power up to 2 W for 10 million cycles, whereas the SP3T switch is capable of handling an RF power of 1 W for 7 million cycles before failure occurs.

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 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 ITS services, millimeter wave frequency bands are used and antennas are required beam scanning ability. Wide angle scanning can be achieved by introducing Abbe sine condition to lens surface shaping. Authors designed a lens antenna that could achieve beam scanning over plusmn30deg. Narrow beam widths were maintained on the scanning planes. However, beam shapes were distorted on the transverse planes. The reason of this beam distortion was due to the phase delay on the aperture. A phase delay correction was achieved through the radiation pattern synthesis of a cluster feed. In this paper, the cluster feed is composed of a group of rectangular horns that corresponding to the situation of an actual antenna. In order to achieve a phase delay correction, a new radiation pattern synthesis method is developed. Resultant excitation coefficients of the cluster feed horns are shown. And the phase correction in the radiation pattern of this feed is clarified. More over, achievements of excellent beam shapes and antenna gain in the wide angle beam scanning are shown.

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.

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

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.

The design and simulation of a 1-bit broadband multi-polarization reconfigurable reflectarray antenna (RRA) in Ka band is proposed in this paper. The unit cell of the RRA consists of four patches and four p-i-n diodes, which can be used in broadband multi-polariztion working mode. By controlling the on-off state of the diodes, two kinds of phase shift states (0° and 180°) can be realized to form a 1-bit phase quantization. The reflection phase of unit cell should compensate for the spatial phase delay from the feed phase center. The simulated results show that the RRA can realized a <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\pm 60^{\circ}$</tex> beam scanning in the frequency range of 31GHz-40GHz.

A novel mm-wave MEMS single pole single throw (SPST) switch has been developed, which is driven by 5.0 V in 10.3 μs. The insertion loss and the isolation at 60 GHz were 1.2 dB and 18 dB, respectively. A two metal layer silicon interposer technology was also developed. We designed single pole double throw (SPDT) switch module, in which two SPST switch are accommodated on the silicon interposer chip. It consists of 3 μm thick Al wires and 12 μm thick low-k benzocyclobutene (BCB) interlayer dielectrics. They enabled sufficient signal integrity for 60 GHz and higher frequencies.

A wide-angle frequency beam scanning antenna based on spoof surface plasmon polaritons (SSPPs) is proposed for planar integrated communication circuits. The SSPP-based antenna is constructed by hole arrays etched on the standard 50 Ω coplanar waveguide, which can achieve ultrawide bandwidth and wide-angle beam scanning from backward direction to forward direction as the frequency changes. The radiation mechanisms of the SSPP-based antenna are based on the higher-order modes of the structure, which have been analyzed by the dispersion curves and electric field distributions. The overall width of the proposed SSPP-based antenna is only 0.95λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> (with λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> being the wavelength of the lowest working frequency). The simulated results show that the proposed frequency beam scanning antenna achieves a wide scanning angle of 129° over a frequency range from 11.7 to 50 GHz (for |S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sub> | <; -10 dB) with an average gain level of 12.38 dBi. The good agreements between the simulated and measured results validate the proposed design.