Yi-Chieh Lee

Bio: Yi-Chieh Lee is an academic researcher from National Taipei University of Technology. The author has contributed to research in topics: Antenna (radio) & Radiation pattern. The author has an hindex of 4, co-authored 6 publications receiving 164 citations.

Design of a Multiband Antenna for Mobile Handset Operations

Abstract: A compact internal antenna is proposed for GSM/GPS/DCS/PCS/UMTS/Bluetooth/WLAN/WiFi/WiMAX applications. The proposed antenna is comprised of a loop antenna and a monopole antenna. The antenna system shows wide multi-operation band as well as good radiation patterns and small volume. The antenna can be printed on the system circuit board of the mobile phone and short-circuited to the system ground plane to form a loop-type structure. A comparison with that of the existing antennas showed that wide impedance bandwidth of the proposed structure can be achieved without increasing the implementation complexity.

A New Printed Antenna for Multiband Wireless Applications

Abstract: This study presents a new design of a printed antenna with simply shaped radiator element for multi-operating bands of the wireless communication systems. With a simple design configuration and slot form on a printed circuit board, the proposed antenna can be used in multiband wireless operations, covering the GSM (880-960 MHz), DCS (1710-1880 MHz), PCS (1850-1990 MHz), UMTS (1920-2170 MHz), 2.4-GHz WLAN (2400-2484 MHz), Mobile-WiMAX (IEEE 802.16e in the Taiwan: 2500-2690 MHz) and 5-GHz WLAN (5150-5350/ 5725-5825 MHz) bands. Several properties of the proposed printed antenna in multiband operation, such as impedance bandwidth, radiation pattern and measured gain are numerically and experimentally investigated.

A New Printed Slot Loop Antenna With Tunable Strips for 2.4- and 5-GHz Wireless Applications

Abstract: This letter presents a new printed slot loop antenna with a pair of tunable strips for wireless communication systems in 2.4-GHz (2.40-2.48 GHz) and 5-GHz (5.15-5.95 GHz) bands. If a pair of the strips is inset at the center of the slot loop antenna, then the resulting impedance bandwidth for the two main operating bands can reach about 100 MHz for the 2.4-GHz band, and 1550 MHz for the 5-GHz band, thus covering the required operations of a wireless local area network (WLAN). Experimental results confirm in detail several properties of the proposed antenna design, such as the impedance bandwidth, radiation pattern and measured gain.

Design and experiment of a rectifying antenna for 900 MHz wireless power transmission

Abstract: A new rectenna with a loop antenna and a designed rectifier by commercial Schottky diode has been developed. The used doubler rectifier provides optimum output DC voltage of 1.54 V as well as 47 % RF-DC conversion efficiency is achieved when 0 dBm RF power is received at 925 MHz. The rectifier has good impedance matching with the loop antenna corresponding to its optimum frequency response.

A HIGP printed antenna at 2.4-GHz operation

Abstract: This presents a printed antenna using the high-impedance ground plane (HIGP) structure in order to improve its radiation performances. The HIGP is a kind of electromagnetic bandgap (EBG) structure to decrease surface waves and to bring an improvement of side lobe level, and to reduce the mutual coupling between the two antennas. As compared to a printed antenna without HIGP, the measurement results show that a 5 to 10 dB reduction in the back lobes and an antenna gain for about 2 dBi addition. Several properties of the proposed antenna performances such as impedance bandwidth, radiation pattern and measured gain have been confirmed experimentally in detail.

A Reconfigurable Wideband and Multiband Antenna Using Dual-Patch Elements for Compact Wireless Devices

Abstract: A reconfigurable wideband and multiband C-Slot patch antenna with dual-patch elements is proposed and studied. It occupies a compact volume of 50 × 50 × 1.57 (3925 mm3), including the ground plane. The antenna can operate in two dual-band modes and a wideband mode from 5 to 7 GHz. Two parallel C-Slots on the patch elements are employed to perturb the surface current paths for excitation of the dual-band and the wideband modes. Two switches, implemented using PIN diodes, are placed on the connecting lines of a simple feed network to the patch elements. Dual-band modes are achieved by switching “ON” either one of the two patch elements, while the wideband mode with an impedance bandwidth of 33.52% is obtained by switching “ON” both patch elements. The frequencies in the dual-band modes can be independently controlled using positions and dimensions of the C-Slots without affecting the wideband mode. The advantage of the proposed antenna is that two dual-band operations and one wideband operation can be achieved using the same dimensions. This overcomes the need for increasing the surface area normally incurred when designing wideband patch antennas. Simulation results are validated experimentally through prototypes. The measured radiation patterns and peak gains show stable responses and are in good agreements. Coupling between the two patch elements plays a major role for achieving the wide bandwidth and the effects of mutual coupling between the patch elements are also studied.

Advances in Antenna Technology for Wireless Handheld Devices

Abstract: The constant evolution of wireless handheld devices together with the apparition of multiple wireless communication systems fosters the antenna community to design new radiating and measurements systems capable of satisfying the market demands. It is an object of the present paper to provide an overview of the evolution that wireless handheld technology has experienced in the last years. In this sense, a description of the evolution of wireless handheld devices, regulations, challenges in today’s smartphones, and handset characterization is reviewed. Finally, recent advances in antenna technology for wireless handheld or portable devices are presented.

Small Antennas in Wireless Communications

Abstract: The objective of this paper is to provide the context, physical insight, and perspective on antennas in wireless communications. Although it does not mean to be comprehensive, the four key technologies related to small antenna designs to be reviewed and discussed, including multiband planar inverted-F antennas, broadband folded patch antennas, compact differentially fed antennas, and miniature circularly polarized patch antennas, would cover a wide range of topical interests and practical applications. A brief overview of computer software for analyzing these antennas is also provided. Hopefully, this paper will be beneficial for the diverse engineering readership of the IEEE.

Integrated Wide-Narrowband Antenna for Multi-Standard Radio

Abstract: An integration concept for multi-standard antennas is described. This technique is based on utilizing a relatively large antenna that is printed on the top side of a substrate, acting as a ground for a smaller antenna. The smaller antenna is printed onto the bottom side of the substrate. To validate this concept, an integrated wide-narrowband demonstrator antenna is presented. This antenna is composed of a shorted microstrip patch integrated with a coplanar waveguide (CPW) fed ultrawideband (UWB) antenna. A prototype of the integrated antenna was fabricated and its performance was verified. This arrangement is a promising candidate for applications where some level of reconfigurability is required. For this reason, a set of external tuning circuits were designed to demonstrate the potential of the proposed configuration for such applications. In order to improve the isolation between the wideband and narrowband ports several modified arrangements were presented and investigated.

On-Board Printed Coupled-Fed Loop Antenna in Close Proximity to the Surrounding Ground Plane for Penta-Band WWAN Mobile Phone

Abstract: A small-size coupled-fed loop antenna suitable to be printed on the system circuit board of the mobile phone for penta-band WWAN operation (824-960/1710-2170 MHz) is presented. The loop antenna requires only a small footprint of 15 x 25 mm2 on the circuit board, and it can also be in close proximity to the surrounding ground plane printed on the circuit board. That is, very small or no isolation distance is required between the antenna's radiating portion and the nearby ground plane. This can lead to compact integration of the internal on-board printed antenna on the circuit board of the mobile phone, especially the slim mobile phone. The loop antenna also shows a simple structure; it is formed by a loop strip of about 87 mm with its end terminal short-circuited to the ground plane and its front section capacitively coupled to a feeding strip which is also an efficient radiator to contribute a resonant mode for the antenna's upper band to cover the GSM1800/1900/UMTS bands (1710-2170 MHz). Through the coupling excitation, the antenna can also generate a 0.25-wavelength loop resonant mode to form the antenna's lower band to cover the GSM850/900 bands (824-960 MHz). Details of the proposed antenna are presented. The SAR results for the antenna with the presence of the head and hand phantoms are also studied.