Fu-Man Yang

Bio: Fu-Man Yang is an academic researcher from Guilin University of Electronic Technology. The author has contributed to research in topics: Wideband & Dielectric resonator antenna. The author has an hindex of 2, co-authored 3 publications receiving 12 citations.

Coupling Reduction for a Wideband Circularly Polarized Conformal Array Antenna With a Single-Negative Structure

Abstract: Decoupling of a wideband circularly polarized (CP) conformal array is studied by a single-negative (SNG) metamaterial (MTM) isolator. The conformal array consists of two wideband CP antennas, which are assembled on an arched carrier, and a wideband SNG structure is placed between the antenna elements for coupling reduction. The SNG structure consists of four wheel-shaped units concentrically. The SNG structure is bianisotropic, and its constitutive parameters are tailored to form a wide isolation band. By using the proposed wideband SNG structure, the mutual coupling between the conformal antenna elements is reduced up to 25 dB at 4.5 GHz, and the mutual coupling is improved in the 3.9–5.05 GHz band. In addition, the loading of the SNG structure has little effect on the axial-ratio bandwidth. Besides, the gain and radiation patterns are improved. This research provides some basis in the decoupling of the conformal array.

Simple and Electrically Small EZR-MZR Resonator With Quasi-Isotropic Pattern

Abstract: A new zeroth-order resonator that composites epsilon-zero resonance and mu-zero resonance characteristics (called EZR-MZR resonator) can be used to design quasi-isotropic antenna. Compared to the presented quasi-isotropic antenna, the EZR-MZR resonator has the advantages of simple structure for high efficiency design and electrically small size. The EZR-MZR resonator includes a patch, a ground plane, and a shorting pin. The single frequency EZR-MZR resonator with rectangular patch has a volume of 0.13 $ {\lambda _{r} \times } 0.20 {\lambda _{r} \times } 0.03 {\lambda _{r}}$ (where $ {\lambda _{r}}$ is the free space wavelength of the resonant frequency $ {f_{r} = 1.500}$ GHz). While the dual frequencies antenna ( $ {f_{r1} = 1.038}$ GHz and $ {f_{r2} = 1.443}$ GHz) with two curved EZR-MZR resonator has a volume of 0.078 $ {\lambda _{r1} \times } 0.214 {\lambda _{r1} \times } 0.024 {\lambda _{r1}}$ (where $ { \lambda _{r1}}$ is the free space wavelength of the resonant frequency $ {f_{r1}}$ ). The field distributions, patterns of different polarizations, Z/S -parameters and parametric studies were used to reveal the operational mechanism of the EZR-MZR resonator antenna. The resonant frequency of the EZR-MZR resonator can be easily tuned by adjusting the size parameters of the resonator, thus, the EZR-MZR resonator with quasi-isotropic pattern is a good candidate to design antenna that accommodates with different RFID frequency.

A Novel Single-Negative Metamaterial Isolator For Compact Wideband Circular Polarization Antenna Array

Abstract: In this paper, a new type of single-negative material structure isolator with a wide band gap of ‘ $4.3\sim 5.9\ \text{GHz}$ is designed, and it is loaded into a broadband circularly polarized array antenna[1] to reduce the mutual coupling between the antenna elements. Compared to the unloaded array, the results show that the coupling of the antenna array with single negative material isolator is reduced by $9.5\text{dB}\sim 32\text{dB}$ in the working frequency band. The isolator has the advantages of easy processing, simple structure and small space.

A Novel Slot-Array Defected Ground Structure for Decoupling Microstrip Antenna Array

Abstract: In this article, a novel slot-array defected ground structure (DGS) for decoupling microstrip antenna array is proposed. The slot-array DGS is etched surrounding each antenna element on the ground plane and parallel to the radiating edges of each antenna element. The decoupling mechanism is elucidated via an equivalent circuit model and the coupled current field analysis, which reveals slot-array DGS has the spatial band-stop characteristic and changes the direction of the partially coupled current, respectively. Both characteristics of the slot-array DGS contribute to mutual coupling reduction. Three practical design examples of applying slot-array DGS to single-linearly polarized (LP), dual-LP, and compact circularly polarized (CP) antenna array are given to illustrate the design process and considerations. The simulated and measured results show that about 50 dB isolation enhancement is obtained by using the slot-array DGS when the edge-to-edge spacing between CP antenna elements is 0.057 wavelength. Additionally, a wheel-shaped absorber based on the electromagnetic loss material is designed and fabricated to reduce the backward radiation caused by slot-array DGS. The absorber has an absorptivity of more than 95% in the frequency range of 1.2–1.35 GHz and suppresses the backward radiation over 12.5 dB in the plane phi = 0° and 16.1 dB in the plane phi = 90° without deteriorating other antenna performances.

A 24 GHz ISM-Band Doppler Radar Antenna With High Isolation Characteristic for Moving Target Sensing Applications

Abstract: A 24 GHz Industrial, Scientific, and Medical (ISM)-band Doppler radar antenna with high isolation is proposed for moving target sensing applications. Both transmit (Tx) and receive (Rx) antennas consist of 2 × 2 microstrip patch antenna arrays. High isolation of the proposed antenna is achieved by inserting periodic Jerusalem cross slot array between Tx port and Rx port, and thus the surface wave from Tx port to Rx port is significantly suppressed. The −10 dB reflection coefficient bandwidth of the proposed antenna is 510 MHz, and the isolation between Tx port and Rx port is higher than 36.7 dB over the 24 GHz ISM band. The simulated half-power beamwidths are 58.53° for E -plane and 47.54° for H -plane. Experimental results show that high isolation can lead to improve Doppler radar performance. The proposed antenna can be a good candidate for contact-free monitoring of the heart rate and respiration rate in healthcare applications.

Enhancing MIMO Antenna Isolation Characteristic by Manipulating the Propagation of Surface Wave

Abstract: Multiple-input multiple-output (MIMO) antennas have been a mainstream technology in fifth generation (5G) communications However, strong mutual coupling between both adjacent and nonadjacent elements is inevitable, especially among highly integrated devices In this paper, a slit embedded mushroom electromagnetic bandgap structure (EBG) is primarily proposed to suppress the propagation of surface wave between antenna elements Subsequently, complementary split-ring resonators (CSRRs) are periodically arranged in two sides of the ground to steer the surface wave By effectively utilizing the unusual electromagnetic property of EBG and CSRR to manipulate the propagation of surface wave, the mutual coupling between antenna elements has immensely alleviated Finally, an H-shape defected ground structure (DGS) is introduced to reinforce decoupling effect In order to validate the feasibility of the design principle, a prototype of the proposed antenna has been fabricated and measured Measured results demonstrate that the decoupling concept in this paper is reasonable and approximately 12 dB reduction of mutual coupling is realized

Bandwidth enhancement and miniaturization of circular-shaped microstrip antenna based on beleved half-cut structure for MIMO 2x2 application

Abstract: In this paper, circular-shaped microstrip antenna was simulated, fabricated, and measured accordingly. As the novelty, to enhance bandwidth and reduce antenna size, beleved half-cut microstrip structure is proposed. Further, this proposed antenna structure will be applied to multiple input multiple output (MIMO) antenna 2 ´ 2. Therefore, this research was investigated conventional circular shape antenna (CCSA), circular shaped beleved antenna (CSBA), and MIMO circular shaped beleved antenna (MIMO-CBSA) as Model 1, Model 2, and Model 3, respectively. An FR4 substrate with er= 4.4, thickness h=1.6 mm, and tan d=0.0265 was used. The simulation has been conducted using Advanced Design System (ADS). The antenna CCSA/CSBA/ MIMO-CBSA achieve 1.831GHz/2.265 GHz/2.256 GHz, -15.13dB/-17.37dB/-17.25 dB, 1.42/1.31/1.33, and 1.474/2.332/2.322 for center frequency, reflection coefficient, VSWR, and bandwidth, respectively. This antenna has a size 63x90 mm and 51.5x90 mm for CCSA (Model 1) and CSBA (Model 2), respectively. After the structure of MIMO 2 ´ 2 was applied, the size of antenna MIMO-CBSA (Model 3) became 180 mm x 180 mm with a mutual coupling (S 21 )=-26.18 dB and mutual coupling (S 31 )=-26.41 dB. The result showed that proposed antenna CSBA (Model 2) has wider-bandwidth of 58,2% and smaller-size of 18.2%. Furthermore, after CSBA (Model 2) structure was applied to MIMO 2 ´ 2 (Model 3) and the MIMO antenna obtain good mutual coupling (<-15dB). Moreover, the measured results are good agreement with the simulated results. In conclusion, all of these advantages make it particularly valuable in multistandard antenna applications design such as GSM950, WCDMA1800, LTE2300, and WLAN2400.

A Low-Profile Decoupling Slot-Strip Array for 2 × 2 Microstrip Antenna

Abstract: Two-dimensional antennas provide additional variables that can be used to control and shape the pattern, and widely used in engineering applications include tracking radar, communications, direction finding and many others However, the reduced mutual coupling becomes more complex due to the mode and strength of the mutual coupling field between sani adjacent elements are different In this paper, a low-profile decoupling slot-strip array (DSSA) for 2 × 2 microstrip antenna is proposed The DSSA consists of a slot array etched on the ground plane and a strip array printed on the radiation patches plane The band-stop effect of the slot array decreases the mutual coupling of both H-plane and D-plane Meanwhile, the coupling current generated by the induced current on strip array can cancel the coupling current generated by excited current, which can significantly improve the E-plane isolation Additionally, the scattering parameters of other three types of antenna which have the different relative positions of feeding ports are also discussed To verify the proposed viewpoint, a 2 × 2 antenna with the DSSA is modeled and manufactured The experimental results demonstrate that a considerable mutual coupling reduction of 332 dB for H-plane, 285 dB for E-plane, and 241 dB for D-plane is achieved while 10 dB bandwidth for S11 remains almost unchanged Fortunately, the experimental results are in good agreement with the simulation results, which confirms that the DSSA has an excellent promising application in two-dimensional antenna