Electrical Characteristics of a Dual-Band Microstrip Patch Antenna for GSM/ UMTS / WLAN Operations

In this paper, two single rectangular patch antennas with a slot are designed and analyzed theoretically from the concept of multi-cavity structure. The theoretical return loss parameters of the antenna electrical characteristics are in good concordance with the advanced design system (ADS) simulation. Two patch antennas with rectangular slot are designed in two different geometries relatively to the feeding point. A thick substrate is used to increase the antenna bandwidth with a good impedance bandwidth performance. 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; the simulation results show the presence of three resonant frequencies (fr1, fr2, fr3) and having the behaviour of a dual band frequency antenna for GSM, UMTS and WLAN system applications. An investigation on the antenna dimension and on the optimum slot position relatively to the feeding point has shown that the second and third resonant frequencies are dependent on the slot position and this dependency is changing differently for both resonant frequencies.