High-gain wideband low-cost series-parallel fed stacked patch antenna array for 60 GHz unlicensed band

Design and Non-Intrusive Diagnostic of High-Gain Wideband Millimeter-Wave Active Antenna Array With Beam-Steering Capability for 5G Application

Design of a Wideband High-Gain Metasurface Antenna Based on Characteristic Mode Theory

High gain wideband 60 GHz antenna based on patch structure with SIW feed and CSRR loading for quasi optical millimeter wave applications

High-Gain Wideband Filtering Quasi-Yagi Antenna Based on High-Order Mode of SSPPs

This paper presents a directional radiation antenna designed for wireless local area network applications. The proposed antenna consists of two FR4 substrates, each with dimensions of 80 mm × 50 mm × 1.59 mm. A rectangular microstrip line is printed on the top surface of the upper substrate and fed by an RF cable through a via. On the bottom surface of the upper substrate, a defected ground plane featuring two semi-ellipses is printed. To enhance the antenna’s directional radiation capability, a substrate composed of artificial magnetic conductors is placed beneath the antenna, maintaining a distance of 25 mm between the two substrates. The proposed antenna operates across the frequency bands of 2.32–3.2 GHz and 4.9–5.9 GHz, effectively covering the IEEE 802.11a/b/g frequency bands of 2.4–2.4835 GHz, 5.15–5.35 GHz, and 5.725–5.85 GHz. It exhibits ideal radiation patterns in both the vertical and horizontal planes, with peak gains of 4.37 dBi at 2.4 GHz and 7.67 dBi at 5.5 GHz. The measured total radiation efficiencies are 67.9% at 2.4 GHz and 85.2% at 5.5 GHz. These measurement results demonstrate the antenna’s strong potential for use in wireless communication applications.

In this paper, a novel 3D-printed high-gain wideband antenna composed of split-ring resonators, a bowl-shaped reflector, and a circularfractal, multilayered, stacked microstrip antenna is presented. The cambered internal surface of the bowl-shaped structure is coated with sliver conductive adhesive. The microstrip antenna and split-ring resonators are installed inside and on top of the bowl-shaped structure, respectively. High gain is achieved due to the split-ring resonators and the curved reflective surface formed inside the bowl-shaped structure. At the same time, a high bandwidth is realized owing to the split-ring resonators and the microstrip antenna’s multilayered, stacked, and fractal structure. The proposed antenna is fabricated and measured. Operating within the frequency range of 5.63–6.78 GHz (reflection coefficient ≤ -10 dB), the antenna achieved a gain between 10.9 dBi and 14.6 dBi, with a peak gain of 14.6 dBi at 5.7 GHz. In addition, the antenna offers other significant advantages–low cost, low cross-polarization, and easy fabrication.

Abstract Superconducting Parametric Amplifiers (SPAs) with near-quantum-limited added noise are crucial for weak signal detection applications such as astronomical receivers, quantum computation, and fundamental physics experiments. Commercially available SPAs include Josephson Parametric Amplifiers (JPAs), which offer high gain but narrow bandwidth performance; and Josephson-junction Travelling Wave Parametric Amplifiers (JTWPAs), which provide broader bandwidth at the cost of a complicated fabrication procedure, lower fabrication yield, and larger footprint area. In this paper, we investigate the parametric amplification of microwave signals in a Josephson array embedded in a low-Q Fabry-Pérot cavity. We fabricated a 500-junction array device and measured >15 dB phase-preserving gain over a ∼350 MHz bandwidth, while offering almost two orders of magnitude improvement in compression point (P 1dB = −106.2 dBm) compared to standard JPAs. Furthermore, using a novel measurement technique, we configured our device to operate in the phase-sensitive mode, measuring a phase-sensitive extinction ratio (PSER) of 42.3 ± 2.81 dB, in line with state-of-the-art values for JPAs. These promising performances, combined with the ease of fabrication and improved yield compared with JTWPAs, underscore the potential of these devices for applications in advanced detection schemes.

Design of Wideband High-Gain Slotline Antennas With Enhanced Frequency Selectivity for 5G Wireless Communication Application

The advancement of communication systems, particularly in antenna design, focuses on achieving low-cost, compact devices with high gain and wide bandwidth. However, at millimeter-wave frequencies, microstrip antennas suffer from severe losses, limiting their performance. Dielectric Resonator Antennas (DRAs), composed of dielectric materials with no metallic losses, offer a promising solution by providing high gain, wide bandwidth, and excellent efficiency for millimeter- wave applications. Despite these advantages, conventional MIMO antennas often use two or three elements with an equal number of ports, resulting in relatively large sizes. To address this limitation, we propose a novel approach utilizing a single- element DRA equipped with three ports for MIMO applications. This design not only reduces the overall antenna size but also optimizes performance. The single-element DRA is initially designed to operate at 26 GHz, with three ports feeding the resonator at distinct orientations.

F-Slotted Multiple-Input Multiple-Output Antenna with High Gain, High Isolation, and Expanded Bandwidth for Ultra-Wideband Wireless Applications

This study presents the design and analysis of a compact metamaterial-based antenna, tailored for wideband wireless communication systems and intended primarily for commercial use. The antenna combines a Co-planar Waveguide (CPW) structure with a Square Ring Resonator (SRR), aiming to boost both bandwidth and gain. Fabricated on a standard FR4 substrate with overall dimensions of 24 × 24 × 1.6 mm³, the antenna’s performance was first optimized using CST Microwave Studio, a full-wave Electromagnetic (EM) simulation platform. Key parameters, such as the reflection coefficient (S11), radiation pattern, and gain were thoroughly evaluated. The simulation predicted a wide operating bandwidth of 7 GHz, ranging from 2.8 to 9.8 GHz, with a peak gain of 4.7 dBi. Following fabrication via photolithography, an experimental validation was carried out using a Vector Network Analyzer (VNA). The measured results demonstrated excellent agreement with the simulations, revealing an even broader bandwidth of approximately 8.2 GHz (1.58–9.8 GHz) and a slightly improved peak gain of approximately 5.14 db. These findings confirm the reliability of the proposed design and underline its potential as a practical solution for modern wideband wireless applications.

This paper introduces an innovative design and analysis of a magneto-electric dipole antenna exhibiting high-gain, ultra-wideband operation, and stable radiation characteristics in the 60-GHz mm-wave band. Furthermore, the trapped printed gap waveguide (TPGW) technology is presented as a low-cost, minimal-loss, and low-dispersion guiding structure to feed the proposed antenna. The antenna covers a relative matching bandwidth of over 33.33% from 50 to 70 GHz with a maximum gain up to 8 dBi. In addition, the antenna is integrated with a perforated dielectric substrate layer lens on the antenna’s broadside location, enhancing the gain by an average of 3 dB along its entire operational bandwidth. Moreover, an efficient approach for designing a large ME dipole antenna array and its corporate feeding network is presented. Both ME-dipole sub-arrays and the out-of-phase power divider with WR-15 standard interface are designed and studied separately, where a systematic design procedure is presented to obtain initial design parameters. A 2 × 2 planar antenna array is designed and implemented, featuring proper integration between the radiating elements and a differentially fed wide-bandwidth TPGW power divider. Then, the operation of the individual components has been assessed using simulation and measurements. Furthermore, an in-depth mathematical analysis is presented to investigate the potential resonance conditions arising from disparities in complementary components. Consequently, a proposed solution is provided to break the resonance loop and shield the two opposing sub-arrays. The 2 × 2 array of ME-dipoles has overall dimensions of 1.61.4 and demonstrates an impedance bandwidth (– 10 dB) exceeding 33.33 at 60 GHz, with a peak gain of over 18 dBi.

In this paper, a wideband circularly polarized folded reflectarray antenna (CPFRA) based on a transmissive linear-to-circular polarization converter is proposed. The CPFRA consists of a primary reflector and a sub-reflector. To achieve broadband performance, a metasurface-based RA element on the primary reflector surface and a transmissive linear-to-circular polarization converter on the sub-reflector surface are applied. Moreover, the transmissive linear-to-circular polarization converter on the sub-reflector surface helps convert linear polarization to circular polarization. To verify the proposed CPFRA, a prototype is designed, fabricated, and tested. The measured results exhibit that the proposed CPFRA presents a 3 dB gain bandwidth of 27.4% and a 3 dB axial ratio bandwidth of 23%. The CPFRA achieves a peak gain of 21.2 dBi with an aperture efficiency of 27.2%. The proposed CPFRA is a promising candidate for millimeter-wave (mm-W) satellite communication applications because of its advantages of high gain, low cost, low profile, and broad bandwidth.

A 6G THz MIMO antenna with high gain and wide bandwidth for high-speed wireless communication

Oil palm fruits farmers in Indonesia have determined the ripeness of oil palm fruits in the traditional way, namely using human eye visuals, which have the weakness of inconsistent levels of accuracy and are prone to errors. The development of increasingly sophisticated technology will help oil palm fruits farmers recognize the characteristics of fruit maturity. Advanced technology, such as frequency modulated continuous wave (FMCW) radar, can assist farmers in accurately identifying fruit maturity. To ensure high accuracy and sensitivity, an antenna with low side lobe level (SLL), high gain, and wide bandwidth in the 23-26 GHz range is required. Using CST Microwave Studio 2023, a designed and simulated antenna achieved an SLL of 24 dB, a gain of 15 dBi, and a bandwidth of 2.5 GHz. These results indicate that higher gain enhances energy directionality and overall antenna performance. Additionally, a smaller angular value improves the antenna’s radiation focus, making it more effective for precision sensing in oil palm fruit ripeness detection.

We propose a new ultra-wideband antipodal Vivaldi antenna design based on the Klopfenstein curve, incorporating exponential slots, horns, and apertures to improve the antenna’s return loss and increase its gain in high-frequency bands. The antenna achieves high gain and wide bandwidth characteristics, with measured −10 dB bandwidth ranging from 2 GHz to 20 GHz, maximum gain of 14 dBi, and gain exceeding 10 dBi from 3.5 GHz to 14 GHz.

Abstract Emerging near‐infrared (NIR) single‐pixel imaging (SPI) technology presents a promising alternative to conventional imaging systems, offering cost efficiency and enhanced durability. The high gain bandwidth product (GBP) of the single‐pixel photodetector (PD) is the primary requirement for high resolution and high imaging speed in SPI. Here, a novel MXene‐Si‐MXene van der Waals (vdW) metal‐semiconductor‐metal (MSM) PD, is demonstrated fabricated via a facile solution process. By incorporating a Ti3C2Tx MXene film, the device exhibits a synergistic photogating effect, leading to an exceptional photogain of up to 7.2 × 103 and a GBP of up to 1.45 GHz under 850 nm illumination at a bias voltage of 2 V, outperforming most currently reported silicon‐based detectors and even many commercial avalanche photodiodes (APDs). Significantly, the high‐quality 512 × 512‐pixel image is successfully achieved at an even 1% sampling rate without any additional filter circuitry by using the PD. The signal‐to‐noise ratio (SNR) of 72.3 dB is the highest value reported to date for SPIs and prior to some NIR array detectors. Thereafter, a high‐quality reconstruction image is also obtained with a SNR of 32.1 dB in visible opaque light. This work paves the way for easy fabrication of high GBP PD for high‐quality NIR SPI.

The rapid development of optical communication has increased the demand for high-speed and high-sensitivity avalanche photodiodes (APDs). However, there is a well-known trade-off between the bandwidth and responsivity of the avalanche photodiodes. To solve this problem, we design and simulate an avalanche photodetector with highly doped, Gaussian-doped, and unintentionally doped hybrid absorption layers. The results show that the maximum 3dB bandwidth of the optimized device increases from 20.1 to 28.1GHz. At a gain of 20, the 3dB bandwidth increases from 18.1 to 22.4GHz, and the gain-bandwidth product experiences an increase of 86GHz. The introduction of the Gaussian-doped region creates a gradually increasing electric field. Due to the effect of negative differential mobility in InGaAs, the electron drift velocity in this region is significantly increased. In addition, we also analyzed the influence of charge layer doping concentration on the APD bandwidth. The study indicates that reducing the doping concentration increases the bandwidth at low gain, while decreasing it at high gain. This research can provide a reference for the structural design of high-speed APDs.

Compact High Gain Wide Band Planar Antenna Design Using Metamaterial Techniques For Wireless Applications