Wang Enhao

Bio: Wang Enhao is an academic researcher from University of Electronic Science and Technology of China. The author has contributed to research in topics: Dielectric resonator & Dielectric resonator antenna. The author has an hindex of 3, co-authored 15 publications receiving 32 citations.

Conformal Bent Dielectric Resonator Antennas With Curving Ground Plane

Abstract: In this communication, conformal concave and convex bent dielectric resonator antennas (DRAs) with the curving ground plane are proposed and investigated. Their resonant frequencies and field distributions are theoretically analyzed through the eigenmode method and single-mode approximation with approximate models containing various boundary conditions. This method shows good accuracy for both concave and convex bent DRAs. Then, the radiation performance of bent DRAs is studied and compared with that of rectangular DRAs and bent microstrip patch antennas. Bent DRAs exhibit superior or flexible performance in terms of bandwidth, gain, and beamwidth. Finally, a prototype is fabricated and measured to validate the research. This communication paves the way for DRAs to the area of conformal, flexible, and wearable antennas.

Wristwatch-Style Wearable Dielectric Resonator Antennas for Applications on Limps

Abstract: A wristwatch-style wearable dielectric resonator antenna (DRA) is proposed for the 2.45-GHz ISM band and sub-6 GHz 5G NR bands around 2.5 GHz, such as the commercial band for China Mobile Communications Corporation. The antenna is designed for applications on forearms and ankles. Practical concerns, including the aligning method, platform size, specific absorption rate, and user effects are investigated. Coplanar feeding structure is applied for alignment and isolation. Analysis of the watchband-like substrate is highlighted to avoid performance degradation. Given that platform configurations are not discretionary in actual devices, parasitic loading is introduced to attain desirable substrate effects and suppress unwanted ones. The user-device interplay is studied in light of actual application scenarios. The specific absorption rate is calculated through multilayer biological tissue models. Meanwhile, radiation variation caused by users is estimated based on human phantom models and measurements.

Estimation and Utilization of Ground Effects on Conformal Dielectric Resonator Antennas

Abstract: Ground effects on arc-shaped conformal dielectric resonator antennas (DRAs) working in the TE $^{\mathrm {z}}_{11 \delta }$ mode are investigated and utilized to attain various radiation performances. Manipulation of directivity patterns are achieved with the help of the three-dimensional curved metal ground. The backlobe, beamwidth, broadside gain, backscattering, and cross-polarization level of the antenna are all readily controllable. The geometric theory of diffraction is applied to provide an intuitional explanation for the radiation changes. Detailed analysis is then conducted from the perspective of ground current. It is found that the current distribution is affected by configurations of both the arc DRA and ground plane. Based on this, analytical methods are developed to calculate the ground effects exclusively for conformal arc-shaped DRAs. Next, the design theory of arc DRAs with curved ground is proposed. To demonstrate it, two conformal DRAs owning directional and wide beams, respectively, are designed as paradigms. At last, a prototype is fabricated and measured for validation.

Fixing and Aligning Methods for Dielectric Resonator Antennas in K Band and Beyond

Abstract: Various conventional and novel fixing strategies for dielectric resonator antennas (DRAs) in K band and beyond are presented and investigated. Their effects on DRAs are studied in depth and explained theoretically through the perturbation theory and basic principles of DRAs. Multifunctional fixtures which achieve different antenna performance are then proposed and discussed. Their mechanisms for offering flexible bandwidth, miniaturization, frequency diversity, low cross polarization, and circular polarization are explained. In practical applications, glue is used besides fixtures to increase reliability, and its influence on antenna performance is difficult to predict. By considering various glue distributions in simulation beforehand, potential performance degradation is successfully mitigated. For validation, a four-element DRA array for 24-GHz automotive radars is fabricated. The results demonstrate that the proposed fixing strategy provides superior characteristics such as shock-resistance, fabrication and assembly simplicity, and robust antenna performance.

Frequency Measurement by FFT Based on FPGA

Abstract: This paper proposes a method for frequency measurement by FFT IP core in FPGA. It can be used in 24GHz Doppler radar system. Currently, almost all the frequency measurement uses frequency counting by singlechip machine(SCM). This method is easy to be affected by noise and keystroke jitter. However, frequency measurement by FFT can easily avoid the effect of noise and jitter and obtain the results quickly and efficiently. Even it can obtain the data of two objects at the same time. This can improve the accuracy of blind area detection and avoid accidents effectively. The cost of the sources and price both are low to meet users' demand. It can be widely used in automotive electronics.

A Road towards 6G Communication—A Review of 5G Antennas, Arrays, and Wearable Devices

Abstract: Next-generation communication systems and wearable technologies aim to achieve high data rates, low energy consumption, and massive connections because of the extensive increase in the number of Internet-of-Things (IoT) and wearable devices. These devices will be employed for many services such as cellular, environment monitoring, telemedicine, biomedical, and smart traffic, etc. Therefore, it is challenging for the current communication devices to accommodate such a high number of services. This article summarizes the motivation and potential of the 6G communication system and discusses its key features. Afterward, the current state-of-the-art of 5G antenna technology, which includes existing 5G antennas and arrays and 5G wearable antennas, are summarized. The article also described the useful methods and techniques of exiting antenna design works that could mitigate the challenges and concerns of the emerging 5G and 6G applications. The key features and requirements of the wearable antennas for next-generation technology are also presented at the end of the paper.

A Road towards 6G Communication—A Review of 5G Antennas, Arrays, and Wearable Devices

Abstract: Next-generation communication systems and wearable technologies aim to achieve high data rates, low energy consumption, and massive connections because of the extensive increase in the number of Internet-of-Things (IoT) and wearable devices. These devices will be employed for many services such as cellular, environment monitoring, telemedicine, biomedical, and smart traffic, etc. Therefore, it is challenging for the current communication devices to accommodate such a high number of services. This article summarizes the motivation and potential of the 6G communication system and discusses its key features. Afterward, the current state-of-the-art of 5G antenna technology, which includes existing 5G antennas and arrays and 5G wearable antennas, are summarized. The article also described the useful methods and techniques of exiting antenna design works that could mitigate the challenges and concerns of the emerging 5G and 6G applications. The key features and requirements of the wearable antennas for next-generation technology are also presented at the end of the paper.

Wideband Dual-Feed, Dual-Sense Circularly Polarized Dielectric Resonator Antenna

Abstract: In this article, a wideband dual-feed, dual-sense circularly polarized (CP) dielectric resonator antenna (DRA) is proposed and demonstrated. An L-shaped slot and a vertical metal strip, fed by the same microstrip line, simultaneously excite the antenna. Using this feeding method, a dual-band, dual-sense CP triangular DRA is obtained by employing the DRA mode excited at the lower band and the hybrid mode excited at the upper band. Building on this initial design, a rotationally symmetric bowtie DRA (bDRA) consisting of two triangular dielectrics is proposed for wideband dual-sense CP operation. An additional excited slot mode widens impedance bandwidth and broadens the axial-ratio bandwidth (ARBW) of the lower band. Meanwhile, a higher order DRA mode excitation widens the ARBW of the higher band. The characteristics of these two DRAs are explored via simulation. Moreover, a bDRA prototype is fabricated and measured. The results demonstrate a directional antenna with a wide 10 dB return loss bandwidth of 63.7%, a broad 3 dB ARBW of 27.1% for the left-hand circular polarization, and a broad 3 dB ARBW of 12.8% for the right-hand circular polarization.

Conformal Polarization Conversion Metasurface for Omni-Directional Circular Polarization Antenna Application

Abstract: In this article, conformal linear-to-circular (LTC) polarization conversion metasurface (MS) in transmission mode is engineered and fabricated. The conformal MS is cylinder-shaped with curved elements bent on the cylinder wall. First, the anisotropic element with the capability of LTC polarization conversion in high transmission efficiency is designed and simulated, and the electromagnetic response on the variation of the curvature radius of the conformal element is discussed. Second, the cylinder conformal polarization conversion MS is engineered based on the anisotropic element. Then by launching a monopole antenna at the center of the cylindrical axis as the feed source, the omni-directional circular polarization antenna is implemented. More importantly, the height, radius, and element number along the longitudinal direction of the MS are optimized to obtain an optimized performance of the antenna. Finally, the antenna system is fabricated, assembled, and measured. The device can operate in 9.9–10.1 GHz with an axial ratio lower than 3 dB along the circumferential direction and at 10 GHz the radiation fluctuation along the circumference is less than 1 dB. This study opens up a new way to design conformal MS on a curved surface and affords an efficient alternative for circular polarization antenna design.

Design and development of a singly-fed circularly polarized rectangular dielectric resonator antenna for WiMAX/Satellite/5G NR band applications

Abstract: A circularly polarized rectangular dielectric resonator antenna (DRA) has been designed (3.7–4.2 GHz) for WiMAX, satellite, and sub-6 GHz 5G NR band communications. A new T-shaped monopole has been used to excite the rectangular DRA. Using proposed conformal metal strip, the higher-order degenerate modes TE δ 13 x and TE 1 δ 3 y have been excited to achieve circular polarization (CP) with improved gain. Further, the bandwidths enhancement has been achieved by placing a parasitic patch of optimized height and width at a specific distance from T-shaped strip on DRA surface to cover the desired frequency band. A signaficant enhancement of ~ 73% in the impedance-matching bandwidth and ~ 75.5% in axial ratio (AR) bandwidth has been achieved. The | S 11 | ≤ 10 dB over a wide bandwidth of ~ 17.3% has been offered by the antenna. A broad axial ratio bandwidth of ~ 17.2% along with a useful gain of ~ 6.32 dBic has been provided by the antenna. The antenna designing and optimization has been carried out using CST® Microwave Studio. A reasonable agreement between simulated and measured results has been observed.