Yi-Chieh Lee

COMPACT PRINTED SLOT ANTENNAS FOR WIRELESS DUAL- AND MULTI-BAND OPERATIONS

This paper presents a printed slot antenna using the printed structure in order to improve its dual-band and compact size performances. The printed slot structure is used as additional resonators to produce dual-band operation for covering the worldwide interoperability for microwave access (WiMAX) and the 5.2-GHz wireless local area network (WLAN) bands. In order to achieve wideband and multi-band operation, the slot antennas with a slotted structure and an inverted-L slot structure for covering the wireless communication operations are developed. Finally, we propose a novel and compact printed slot antenna with mixing slot structures to obtain and cover for the 2.4-GHz WLAN (2.4–2.484 GHz), the WiMAX (IEEE 802.16e in the Taiwan: 2.5–2.69/3.5–3.65 GHz), and the 5GHz WLAN (5.15–5.35/5.725–5.825 GHz). Several properties of the proposed antennas for dualand multi-band characterize radiation performances such as impedance bandwidth and radiation pattern. Measured gain has been confirmed experimentally for the multi-band wireless communication systems.

Design of a Multiband Antenna for Mobile Handset Operations

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

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.

Dual-Band Dipole Antenna for RFID Tag Applications

New design of a dipole antenna with rectangular fractal shape radiator element with two operating bands for radio frequency identification (RFID) is presented. By using fractal shape slot and metal meander patch, the proposed antenna has the wide and dual measured return loss bandwidth. Besides, the omnidirectional radiation pattern of the design antenna cover the entire frequency range including ultra high frequency (UHF, 860 MHz~960 MHz) band and microwave (2.45 GHz) band has been obtained. Several properties of the proposed antenna for dual-band operation such as impedance bandwidth, radiation pattern and measured gain have been investigated numerically and experimentally in detail.

CPW-Fed UWB slot antenna

A new design of slot antenna by CPW-fed is proposed for ultra-wideband (UWB) applications. The proposed antenna consists of a CPW-fed, and a pair of symmetry curved radiating slot. Using tapered slot forms obtain the bandwidth from 3 GHz to 20 GHz over entire UWB spectrum. The proposed antenna could cover simulated and measured results show that new design CPW-fed UWB slot antenna keeps acceptable patterns and gains. Detail design and experiment are showed and discussed in this paper.

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

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.

A Tapered Monopole Antenna with Band Notch Function for Ultra-Wideband Communication

A tapered monopole antenna that has a frequency band notch function is proposed. The antenna includes a semicircle shaped patch, two semicircle ground planes and a CPW-fed excitation to cover the ultra- wideband frequency operation (3.1 GHz ~ 10.6 GHz). By modifying the U-shaped slot, the frequency band notch within the operating bandwidth can be easily changed. The measured results show a return loss bandwidth of 12.3 GHz (2.7 GHz ~ 15 GHz), omnidirectional radiation patterns and reasonable gain over the UWB operating bandwidth.

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

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

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.

CPW Band-Stop Filter with Tapered-Shaped Defected Ground Structure

A CPW band-stop filter that has a tapered-shaped defected ground structure (DGS) is demonstrated. The proposed band-stop filter includes symmetrical tapered-shaped DGS and a CPW-fed excitation to obtain two resonance frequency nulls and wider -lOdB operating bandwidth. By modifying tapered-shaped DGS structure and centre strip width (w), the operating bandwidth can be easily adjusted. The simulated and measured results show accepted S-parameters. On other designs, the multisections filters using tapered-shaped DGS structure and CPW filter with dual-tapered-shaped DGS are designed and experimented.