Transmitarray Antenna Research Articles

Analytical design of low-profile wideband multi-layer transmitarray antenna for Ku band

Analytical design of low-profile wideband multi-layer transmitarray antenna for Ku band

Design and implementation of a novel wideband dual‐polarised transmitarray antenna based on tightly coupled cross dipole cells

AbstractA novel broadband dual‐polarised transmitarray antenna (TA) utilising tightly coupled cross dipole cells is proposed in this work. The transmitarray cell using the tightly coupling wideband principle comprises two radiation patches designed as two orthogonal planar dipoles with four interdigital capacitors, two meandered parallel plate transmission lines, and a ground. Each cell has a square shape and a dimension of approximately 0.28 where is the wavelength at central frequency 5.5 GHz. The transmitarray cell can achieve 475° phase shift at central frequency and transmission magnitude better than −2.5 dB within the working band. To verify the feasibility of this design, a tightly coupled dual‐polarised transmitarray antenna (TCDPTA) is modelled and manufactured. The transmitarray aperture size is approximately 4.1 4.1 . The simulation and measurement illustrate that the TCDPTA has stable and distortion‐free main beams whose side lobe levels are generally below −10 dB in the band of 3.0–8.0 GHz. The measured gain at central frequency is 16.2 dBi and peak gain is 19 dBi at 7.5 GHz. The working bandwidth is 90.9% and 3 dB gain bandwidth is 66.7%. The measured cross‐polarisation levels are below −15 dB at axial direction. This TA has potential applications for high‐date‐rate communication and high‐revolution radar imaging systems at C‐band.

A Dual-Band Dual-Circularly Polarized Transmit-Array Antenna and Its Application for Four-Color Scheme Multibeam Generation

A Dual-Band Dual-Circularly Polarized Transmit-Array Antenna and Its Application for Four-Color Scheme Multibeam Generation

A quad-polarization reconfigurable transmitarray antenna with beam-scanning and reconfigurable polarization capabilities

Abstract In this paper, a novel quad-polarized electronically reconfigurable transmitarray antenna(QRTA) is proposed, which can actively switch among four linear-polarization modes and steer beam-scanning in these polarization modes. The QRTA element follows a receiving-transmitting structure. Its receiver or transmitter is composed of four rotationally symmetric patches and a coupling patch. Four rotationally symmetric patches generate x- and y-polarization modes, while coupling patches on the top and bottom layers of the QRTA element are designed to synthesize x-, 45◦-, y-, and 135◦-polarization modes. The QRTA element utilizes a reverse symmetry current method to achieve a 180◦ phase difference in the radiated electromagnetic waves. By manipulating the state of the p-i-n diodes, the proposed QRTA element can achieve four LP functions and a 1-bit phase shift. Based on the proposed novel QRTA element, a 10 × 10 elements QRTA prototype is fabricated and measured. The measured results demonstrate that the proposed QRTA can electronically switch between four LP modes and achieve beam-scanning in those LP modes. The proposed QRTA shows several advantages, including low cost, multi-polarization capability, high gain, and beam-scanning, which means that it can enhance the polarization capabilities and intelligence of wireless communication systems.

Metasurface Source Antenna Gain Improvement Using Simple Side Metal Structure.

As metasurfaces are in the spotlight, research is being conducted to incorporate them into transmitarray (TA) antennas. Among these, as an attempt to create a low-profile design, a patch antenna classified as low-gain can be utilized as an appropriate source antenna. However, for high efficiency of the TA, the gain of the source antenna must be fundamentally improved. For this, a simple side metal structure was applied to a metallic cross-type slot transmitarray. This acts as a resonant element and reflector by utilizing the electromagnetic wave radiated from the source antenna. The changes in the center frequency and gain due to the application of the side metal structure to the source antenna were analyzed. The gain of the source antenna was improved by a total of 4.63 dB. This is expected to be applied to create various source waves and to conduct future research on improving the gain in transmitarray antennas.

Wide-angle low-scattering transmitarray antenna based on transmit-reflect selective metasurface

Abstract A high-gain transmitarray antenna with low radar cross section (RCS) properties is presented in this paper. Compared with conventional high-profile multilayer designs, we introduce a transmit-reflect selective metasurface integrated with high-gain transmission and random scattering functions, achieving a reduced thickness of 0.13 λ 0 (where λ 0 is the wavelength at the center frequency). For the meta-atom design, we combine geometric rotation and dimension optimization to realize 1-bit independent transmit and reflection phase modulation, respectively. Moreover, in metasurface coding strategy, we employ an initial phase optimization method and a simulated annealing algorithm to determine the optimal coding matrices. The experimental results demonstrate high-performance radiation characterized by the peak gain of 23.6 dB, maximum aperture efficiency of 28.5%, and 3 dB gain bandwidth of 18.4%. For x-polarization, measured 10 dB RCS reduction bandwidth under transverse magnetic (TM) 0°-45° and transverse electric (TE) 0°-20° incidence are 9.02–11.36 GHz. For y-polarization, 10 dB RCS reduction bandwidth under TM 0–60° and TE 0–30° incidence is 8.82–10.96 GHz.

A broadband and high‐efficiency folded transmitarray antenna

AbstractA folded transmitarray antenna (FTA) with low profile, high efficiency, and broadband is proposed. The transmission unit‐cell is composed of two metallic layers of bowknot‐shaped patches printed on a single layer of dielectric substrate. By regulating bowknot‐shaped patches' dimension and mirroring elements' top and bottom layers, 360° phase swing and high transmission magnitudes are obtained. With the introduction of a reflectarray integrated with a feed horn in the middle, an FTA is designed based on ray tracing principle, leading to a profile reduced to 1/3 of the focal distance of traditional transmitarrays. According to testing results, 15.5% 1 dB gain bandwidth, 30.9% 3 dB gain bandwidth, and 42.3% peak aperture efficiency are achieved. These outstanding performances demonstrate its good potential for a wide range of high‐gain applications.

A Broadband High-Efficiency Spin-Decoupled Folded Transmitarray Antenna With Independent Beam Control

A Broadband High-Efficiency Spin-Decoupled Folded Transmitarray Antenna With Independent Beam Control

A wideband transmitarray antenna based on polarization conversion metasurface with 2‐bit phase compensation

AbstractA wideband transmitarray antenna (TA) incorporating a polarization conversion metasurface (PCM) is proposed. Four PCM elements with annular metallic polarizers are utilized to provide 2‐bit phase compensation without altering the geometric parameters of the elements, resulting in a wideband TA with a bandwidth comparable to that of the individual elements. A prototype of the proposed TA is designed, fabricated, and measured. The measured 1‐ and 3‐dB gain bandwidths of the proposed TA are found to be 10–13.6 GHz (30%) and 9.2–15 GHz (48.3%), respectively, while the effective 1‐dB transmission band of the individual elements is 7.8–14.6 GHz. The similarity between the bandwidth of the proposed TA and that of elements used in our design demonstrates less wastage of element bandwidth by the proposed approach. A measured peak gain of 27.2 dBi and a peak aperture efficiency (AE) of 48.7% highlight the promising potential of the proposed TA for long‐distance communication, point‐to‐point communication, and other applications.

Wideband dual-polarized high-efficiency transmitarray using isolated metal elements

A wideband dual-polarized high-efficiency transmitarray antenna utilizing the isolated metal elements is proposed. First, a dual-polarized isolated metal element supported by a substrate frame is introduced. Each array element is isolated from adjacent elements by gaps. To realize the element, a substrate frame is used to completely fill the gaps and support the elements. As a result, the limitation of metal connections is overcome, and the transmitarray bandwidth is significantly enhanced. Based on equivalent circuit of the element, its wideband operating mechanism is revealed. Then, to reduce the manufacturing difficulties and costs while maintaining electrical performance, PCB technology is applied to the transmitarray fabrication, integrating the elements and the substrate frame. Finally, a wideband dual-polarized substrate-based metal transmitarray is designed, fabricated and measured. The measured results of the prototype indicate that its gain at the center frequency 10.2 GHz is 26.9 dBi, its 1-dB gain bandwidth is 23.4%, its efficiency is 56.1% and its lowest efficiency across the 1-dB gain bandwidth is 38% at 12.4 GHz. To the best of our knowledge, this is the first time a wideband two-layer substrate-based metal transmitarray has been proposed and implemented.

A single‐channel transmitarray antenna with abilities of super resolution and digital beamforming

AbstractA single‐channel transmitarray antenna with abilities of super resolution and digital beamforming (DBF) is proposed. The amplitude and phase distributions on the array aperture are reconstructed through beam switching with a single channel. By finding and solving relations between distributions and received signals of beams, aperture distributions can be reconstructed. The ill‐conditioned problem caused by limited scanning range and angular interval is solved using the regularization method. The obtained distributions can then be delivered to super‐resolution algorithm to obtain super resolution, or used to produce shaped beams by DBF. On the basis of the proposed theory, a bifocal beam‐reconfigurable transmitarray is designed and tested as a single‐channel DBF antenna without special and additional hardware design. It has the outstanding advantages of low cost, simple structure, low energy consumption, and high working frequency.

A Novel Approach for the Enhancement of Security through Defining the Spatial Secrecy Outage Probability in the Industrial Internet of Things

The rapid development of the Industrial Internet of Things (IIoT) has brought enormous opportunities to the industrial environment, but has also posed significant challenges to network security, especially physical layer security, which is crucial for the reliable transmission of messages among interconnected devices and sensors. Focusing on enhancing the physical layer security in IIoT communication, this paper proposes a mechanism for the Spatial Secrecy Outage Probability (SSOP) to ensure the secure transmission of data. The SSOP algorithm assumes that the location of legitimate devices is known, while the eavesdropper devices have a random distribution of locations, forming the SSOP model related to the device locations from the perspective of insecure regions (ISRs) and secure regions (SRs), and the closed-form expression for its upper bound is derived. Subsequently, under the constraint of the SSOP conditions, we establish an optimization model with the objective of system throughput maximization based on the Spatial Secrecy Outage Probability (SRM-SSOP). By optimizing the transmission rate of legitimate channels or controlling the transmission power, the maximization of the system throughput can be achieved, thus reducing the consumption of communication resources. Through sophisticated modeling and simulation in MATLAB, we verified the accuracy of the definition and derived the upper bound of the SSOP. The experimental results also show that the SSOP algorithm gradually converges to a specific value as the number of antenna elements increases. In addition, we observed that, when the receiver device is aligned with the normal direction of the transmit antenna array, the SSOP reaches a minimum value. This performance is crucial for understanding and optimizing the security performance of IIoT communication systems.

The Evolution of Printed Lens and Transmitarray Antennas: Navigating representative past, present, and future designs and manufacturing techniques

The Evolution of Printed Lens and Transmitarray Antennas: Navigating representative past, present, and future designs and manufacturing techniques

Low profile wide band high gain transmitarray antenna for Ku band applications

A wideband transmissive surface with identical slots on 15 × 15 unit cells proposes in this article. The high gain transmitarray antenna presents using Huygens' principle at 15 GHz. The transmitarray surface consists of trilayer H-shaped slots on the middle of four symmetric slots on the edges of the unit cells. The placed slots induce Huygens’ resonances at three frequencies, 13.5 GHz, 15 GHz and 16.7 GHz which is caused by electric and magnetic surface currents on the transmitarray surface. This makes a wide bandwidth for the antenna performance. 360° phase distribution is obtained by increasing the H-shaped slots legs. Since no dielectric substrate used between layers, the transmission coefficient is near 1 (0 dB) through the whole range. For experimental results, the trilayer artificial metallic surfaces with substrateless conductive slotted unit cells is fabricated. The test results presented the transmitarray antenna peak gain is measured 28.6 dB at operating frequency, 15 GHz. Ultra wide band antenna with 3 dB gain bandwidth of 30% and high aperture efficiency of 42.66%.

Focal Plane Array Chip With Integrated Transmit Antenna and Receive Array for LiDAR

Focal Plane Array Chip With Integrated Transmit Antenna and Receive Array for LiDAR

A double-layer dual-polarized metasurface transmitarray antenna with low profile

In this paper, a polarization-independent chain Huygens’ metasurface is proposed. It is polarization multiplexing of two chain structures. Owing to the polarization-independent property, it can be conveniently applied to design double-layer dual-polarized transmitarray antennas (TAAs) with low profile. The measured results show that, for the designed low-profile dual-polarized TAA, its peak gain is 29.7 dBi at 28 GHz with aperture efficiency of 48.9 %, and the 3-dB gain bandwidths is 8.8 %. With the F/D ratio of only 0.36, the proposed low-profile dual-polarized TAA based on the chain Huygens’ metasurface has critical applications in antenna engineering.

A Collaborative Control Method of Transmission Amplitude and Phase for Transmitarray Antenna Design

In this paper, a collaborative control method of transmission amplitude and phase for transmitarray antenna (TA) design is proposed. In this proposed method, one of the most popular hypersurface fitting models, Gaussian stochastic process (GP) model, is utilized to construct an accurate surrogate model. Following this implementation, a mapping relationship between structural parameters of TA unit cell and its transmission amplitude and phase is established. The most advantage of this method is its applicability for general TA designs because it is much difficult to control the amplitude and phase of unit cell independently through adjusting separate structural parameters. To verify the high efficiency of the proposed method, three TA antennas with different scanning angles are designed to obtain high sidelobe suppression level. Measured results show that the proposed collaborative control method of amplitude and phase is much promising for high sidelobe suppression level in TA designs.

A Broadband Transmitarray Antenna Using a Metasurface-Based Element for Millimeter-Wave Applications.

In this manuscript, a broadband transmitarray antenna (TA) using a metasurface-based element is presented for millimeter-wave communication applications. The metasurface-based TA element adopts a receiver-transmitter configuration: metasurfaces are applied as the receiver and transmitter, and slot-coupled differentially fed striplines are used as the phase compensation. The designed TA element achieves good transmission performance with a more than 360° transmission phase shift range and less than 1-dB transmission insertion loss within a wide frequency range. To verify the proposed TA, a prototype is fabricated based on the conventional printed circuit board (PCB) process, and a pyramid horn is designed as the source. The measured results show that the proposed TA with the differential feed network presents a 1-dB gain bandwidth of 26.2% from 23.5 to 30.5 GHz and a peak gain of 24.5 dBi. The designed TA is a promising alternative for millimeter-wave communications applications because of its high gain, broad bandwidth, low costs, and convenient integration with other circuits.

High-Efficiency Wideband Transmitarray Antenna Using Polarization-Rotating Elements with Parasitic Stubs

High-Efficiency Wideband Transmitarray Antenna Using Polarization-Rotating Elements with Parasitic Stubs

A wideband 1 bit reconfigurable transmitarray antenna based on proximity-coupled feed patch element

ABSTRACT In this paper, a wideband 1-bit reconfigurable transmit array antenna (RTA) is proposed. The 1-bit RTA element consists of a passive receiving antenna and a reconfigurable radiating antenna, which adopt a proximity-coupled feed method to broaden the transmission bandwidth. Two p-i-n diodes are integrated into the reconfigurable receiving antenna to control the current distribution. By switching the states of the p-i-n diodes, the reconfigurable radiating antenna can achieve a 1-bit phase shift. Element simulation results show that the proposed RTA element can achieve a 3 dB transmission bandwidth of 21.5%. A 100-element RTA prototype with 200 p-in diodes is designed, fabricated and measured. The measured results show that the peak gain is 18.8 dBi at 5.05 GHz, corresponding to an aperture efficiency of 20.8%, and the 3 dB gain bandwidth is 17.1%. Furthermore, the scanned beams can reach −32° and −36°, respectively, in the E- and H-planes.