Design of a Dual-Band Microstrip Patch Antenna for GSM/UMTS/ISM/WLAN Operations Said GHNIMI*, Adnen RAJHI* and Ali GHARSALLAH*
*Unité de recherche Circuits et Systèmes Electroniques Haute Fréquences, Faculté des sciences de Tunis firstname.lastname@example.org adnen.Rajhi@esti.rnu.tn email@example.com
Abstract: This paper describes the design of a dual-frequency antenna for GSM and UMTS/LAN/ISM system applications. A patch antenna with rectangular aperture is designed by using a thick substrate in order to increase the bandwidth. After this, we have extracted the reflection coefficient of the considered antenna excited by a probe feed and by optimizing the antenna dimensions and the aperture position. The simulation of this antenna has been made by advanced design system (ADS) in the band of frequency between 50 Hz and 3.2 GHz, leading to three resonant frequencies and showing a good impedance bandwidth performance to cover the required bandwidth of the GSM (890– 960 MHz), UMTS (1920–2170MHz) and WLAN/ISM (at 2.45GHz) bands. Key words: Microstrip patch Antenna, dual-band, GSM, UMTS, ISM and WLAN.
In the last few years the Global System for Mobile communications (GSM) [RAM 03], the Universal Mobile Telecommunications System (UMTS) bands [HOL 01] [SUR 06] [HUB 00], and one of the ISM bands is at 2.45 GHz which is also the same band for the Wireless Local Area Network (WLAN) system and Bluetooth applications have been presented in the published papers [LIU 07] [LEE 97] [MAL 03]. In the literature, several antennas have been used in a variety of applications for which new and more restrictive requirements in the design of the antenna have been introduced. In particular, for highprecision GSM, UMTS and ISM/WLAN applications, few solutions have been proposed by [CHA 02] [TUN 02] [CIA 03]. Unfortunately, these solutions, it may easily provide the desired electric characteristics, but it becomes impractical due to the operational requirements on size and weight. The complicated geometry of these various antennas presents the problem at the levels of the realization, which require very sophisticated equipments and a higher cost for the designer, and for the integration of these antennas in some applications such as the base station of mobile communication. The proposed antenna presents a simple technique; indeed, the use of a simple substrate of low cost and larger height allows a good impedance matching; then, it is necessary to sweep on the dimension of the antenna L, W and the aperture size, and the juxtaposition of the feed probe position allows us to create new resonant frequencies. Once the dimensions of the resonant antenna are determined, the simulated coefficient of reflection S11 is extracted. Furthermore, in order to satisfy the demanded precision and reliability, for a high performance proposed antenna a simple modification on the patch surface has been introduced. The organization of this paper is as follows, section 1, the design for the proposed dual-band rectangular patch antenna is presented, in section 2; we present results and discussions for the performance of the proposed antenna. Section 3, contains conclusions, and recommendations for further studies.
1. Antenna Design
The geometry of the proposed dual-band antenna is based on the microstrip antenna technique which is the most popular because of the ease of analysis and fabrication and having attractive radiation
SETIT2009 characteristics, it consists of a rectangular metallic patch with a rectangular slot mounted on a grounded substrate as shown in figure 1. This microstrip antenna is low-profile conformable to planar surfaces, simple and inexpensive to fabricate using the modern printed circuit technology and it can be used in many applications such as the phased array for...