Analysis and Design of Electrically Small Printed Inverted F Antenna (PIFA)

Abstract

Recent advances in the eld of wireless communication have created a con- siderable demand for the design of compact wireless devices. Antenna being the most important component of such device plays an important role in de ning the overall performance of these devices. Due to micro-fabrication technology the size of electronic circuits and other components in a wire- less device has considerably reduced. However, miniaturization of antenna is still challenging task as its size is a direct function of the operating wave- length as opposed to the fabrication technology for the electronics. Designing electrically small antenna (ESA) requires fundamental understanding of the trade-o between antenna size and its bandwidth, gain and e ciency. There is a huge requirement of designing ESAs for many applications operating in the frequency range between 700 MHz to 6 GHz. For such bands, printed antennas are mostly used since they are low-pro le, light weight, can be easily manufactured and integrated with accompanying electronics. Printed Inverted-F antenna (PIFA) is one such antenna which is widely used in wire- less communication system such as mobile phones and WiFi systems. But unlike traditional antennas, the analysis and design of PIFA is still challeng- ing. Furthermore, its miniaturization is less explored and there is lack of understanding about the procedures to make a PIFA electrically small, and to know its fundamental limits and trade-o s. In this thesis basic theory of ESA, merits and demerits of di erent PIFA's miniaturization techniques is discussed in detail and on the basis of those techniques two design are proposed for WLAN 2.4/5 GHz applications. A generic design procedure is explained that can be opted to design the anten- nas at other desired frequencies.