Broadband planar antenna with improved pattern bandwidth

Abstract

This paper presents the design of a broadband planar inverted-F antenna whose geometry splits the top (radiating plate), short, ground, and capacitive feed plates into two parts. The proposed geometry together with the capacitive-feed technique make it possible to achieve both measured-pattern and impedance bandwidths of about 52.44% (1.66 GHz - 2.84 GHz) and 8% (3.36 GHz - 3.64 GHz) for VSWR ≤ 2.0. These values are larger than the bandwidth obtained using a traditional wire-fed PIFA or other capacitive feeding techniques. A constructed prototype is enough to simultaneously cover various frequency bands, namely DCS 1800, DCS 1900, UMTS, Wi-Fi, 2.4GHz, WiMAX (2.3-2.5 GHz; 3.4-3.5 GHz), and Bluetooth. Radiation patterns are reasonably omni-directional throughout the whole operating bandwidth.