LOW PROFILE ANTENNAS FOR MOBILE COMMUNICATION APPLICATIONS

Abstract

The development of a small antenna plays an important role in the rapidly growing mobile communication market. As the size of the mobile phone is becoming progressively smaller, more and more attention is paid to develop small-size and lowprofile antennas for mobile handsets. The increasing number of communication bands such as GSM, DCS, PCS, WLAN, Bluetooth, demand multiband antennas. Due to the limited space and placing problems it is not feasible to place a separate antenna for each application in the handset. Miniaturized multiband antenna designs are therefore needed for the modern multistandard handsets. The planar inverted-F antenna (PIFA) is one of the most popular antennas for various mobile communication applications due to its compact size, simple structure and multiband operation. In this thesis Multiband planar inverted-F antenna with 6mm height was designed, simulated and fabricated to operate in the GSM, DCS and WLAN bands. The triple band antenna is realized by etching two narrow linear slots in the patch and the use of two shorting strips to achieve good impedance matching. The two linear slots introduced in the patch determine the operation in the DCS and WLAN bands. The design and simulation of the antenna is carried out using FEM (Finite Element Method) based electromagnetic simulator HFSS. The prototype of the antenna has been fabricated and tested. The measured results are compared with simulated ones, and there is a good agreement. But the height of 6mm is less attractive for modern slim handsets, therefore the reduced height multiband Planar Inverted-F antenna with 2mm height was also designed, simulated and fabricated. The reduced height feature makes it attractive for multiband slim handsets. The prototype antenna has been fabricated and the measured results match well with the simulated results.