Hai Zhou

Multimode Decoupling Technique With Independent Tuning Characteristic for Mobile Terminals

The isolation between antenna elements is a key metric in some promising fifth generation technologies such as beamforming and in-band full-duplex. However, the multimode decoupling technology remains a great challenge, especially for mobile terminals. One difficulty in achieving multidecoupling modes is that the operating modes of closely packed decoupling elements have very strong mutual effect, which makes the tuning complicated and even unfeasible. Thus, in physical principle, a novel idea of achieving the stability of the boundary conditions of decoupling elements is proposed to solve the mutual effect problem; in physical structure, a metal boundary is adopted to realize the stability. One distinguished feature of the proposed technique is that the independent tuning characteristic can be maintained even if the number of decoupling elements increases. Therefore, wideband/multiband high isolation can be achieved by using multidecoupling elements. To validate the concept, two case studies are given. In a quad-mode decoupling design, the isolation is enhanced from 12.7 to >21 dB within 22% bandwidth by using a

A Novel Reconfigurable Metal Rim Integrated Open Slot Antenna for Octa-Band Smartphone Applications

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Design of a Wideband Antenna With Stable Omnidirectional Radiation Pattern Using the Theory of Characteristic Modes

decoupling structure. The mechanism of the decoupling technique and the mutual effect between decoupling elements are investigated.

A Compact and Low-Profile MIMO Antenna Using a Miniature Circular High-Impedance Surface for Wearable Applications

In this paper, a novel reconfigurable open slot antenna has been proposed for LTE smartphone applications to cover a wide bandwidth of 698–960 and 1710–2690 MHz. The antenna is located at the bottom portion of the mobile phone and is integrated with metal rim, thereby occupying a small space and providing mechanical stability to the mobile phone. Varactor diode is used to cover the lower band frequencies, so as to achieve a good frequency coverage and antenna miniaturization. The operational principles of the antenna are studied and the final design is optimized, fabricated, and tested. It has achieved the desired impedance bandwidth and the total efficiency of minimum 50% in free space throughout the required bands. The antenna performance with mobile phone components and human hand is also been studied. Furthermore, the SAR in a human head is investigated and is found to be within allowable SAR limits. Finally a multiple-input multiple-output antenna configuration with high isolation is proposed; it has an identical reconfigurable open slot antenna integrated at the top edge of the mobile phone acting as the secondary antenna for 698–960 and 1710–2690 MHz. Thus the proposed antenna is an excellent candidate for LTE smartphones and mobile devices.

A wearable antenna design using a high impedance surface for all-metal smartwatch applications

In this communication, the design procedure of a wideband antenna with omnidirectional radiation pattern is demonstrated based on the theory of characteristic modes. Consisting of a dipole and a loop antenna, the antenna has a very simple structure. A wide impedance bandwidth is obtained because of the simultaneous excitation of the antenna’s first two modes. Meanwhile, due to the fact that these two modes share a similar omnidirectional radiation pattern, a stable radiation pattern is also achieved across the operating frequency band. In order to identify the antenna’s different modes, a characteristic mode analysis of the antenna is carried out first. Then, a feed configuration is specifically designed to excite the desired modes. To validate the antenna design, a prototype was fabricated and tested. Measured results agree well with the simulated ones. Measurement shows that a wide impedance bandwidth of 44.2% with

A novel mm-Wave phased array antenna with 360° coverage for 5G smartphone applications

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A Compact and Low-Profile Loop Antenna With Six Resonant Modes for LTE Smartphone

dB (1.85–2.9 GHz) and stable radiation patterns at both E-plane and H-plane were achieved over the operating frequency band.

A high gain steerable millimeter-wave antenna array for 5G smartphone applications

A new miniature circular high-impedance surface (HIS) is used to design a compact and low-profile multi-in multi-out (MIMO) antenna for wearable applications. The antenna is designed to operate from 2.4 to 2.49 GHz for wireless local area network application. By employing a pair of degenerated characteristic modes of a circular loop antenna, the MIMO antenna can achieve a good port-to-port isolation (>15 dB) without increasing its geometric size. A four-element HIS is chosen to match the antenna profile, and a 2 dBi antenna gain improvement is observed. The design was optimized considering the effect of packaging and then a prototype with the optimal parameters was fabricated and tested. Measurement results are in good agreement with simulation results. Furthermore, the loading effect due to lossy human tissue is also considered and the results show that the antenna has a robust performance against the human phantom and a low specific absorption rate can also be obtained.

Corrections to “Design of a Wideband Antenna With Stable Omnidirectional Radiation Pattern Using the Theory of Characteristic Modes”

A smartwatch antenna with a novel high impedance surface (HIS) is investigated in this paper. In order to fit the all-metal smartwatch applications, a non-planar HIS is proposed instead of using a traditional planar one. With the presence of the HIS, the wrist phantom has a slight impact on the antennas performance and a low SAR can also be obtained. The antenna can achieve a gain of >1.3 dBi and an efficiency of >40% from 2.4 to 2.484 GHz even when it is mounted above a wrist phantom. Hence, it can work effectively for WIFI or Bluetooth system.

Corrections to “Design of a Wideband Antenna With Stable Omnidirectional Radiation Pattern Using the Theory of Characteristic Modes” [May 17 2671-2676]

In this paper, a novel capacitive coupled patch antenna array capable of providing 360° coverage is proposed. The design and performance of the antenna element is discussed. The proposed antenna design is positioned in the mobile phone chassis as a set of 4 sub-arrays each with 12 antenna elements to provide high gain around 27 dBi with each sub-array providing 90° coverage. The antenna array covers the frequency range of 24–28 GHz which is a promising band for future 5G based smartphone services. The antenna array performance is evaluated. The proposed antenna exhibits a uniform radiation pattern with a stable gain when integrated with the mobile phone chassis.