Design and analysis of a dual-band folded PIFA for TVWS and 2.4-GHz ISM applications

This paper presents the design and analysis of a dual-band planar inverted-F antenna (PIFA) with three resonance modes to satisfy the requirement for both TVWS and 2.4-GHz ISM applications. The third resonance mode is achieved by straightforwardly cutting a U-shaped slot on the inner patch of the PIFA around the feeding point while no parasitic element is required, thus the proposed antenna can be easily fabricated by folding a single copper sheet. Furthermore, the frequency of each resonance mode can be flexibly adjusted by tuning different dimension parameters so as to control the frequency and bandwidth (BW) of the two operating bands. The measured fractional BW of the two frequency bands are 54% (460–800 MHz) and 11.3% (2.34–2.62 GHz), respectively.