Compact Printed Monopole Antenna With Inverted L-shaped Slot for Dual-band Operations

In this paper, we proposed a compact printed monopole antenna with an inverted L-shaped slot for dual-band operations. Two operating frequency bands are achieved with the use of an inverted L-shaped slot etched on the radiating strip for bandwidth enhancement and a defected ground structure for return loss improvement in the higher frequency band. The measured results show that the proposed antenna has impedance bandwidths (S11< -10 dB) of 270 MHz (1.81–2.08 GHz) and 340 MHz (2.36–2.70 GHz), covering the required bandwidths for PCS (1850.5–1989.5 MHz), CDMA 2000 (1850–1990 MHz), TD-SCDMA (1880–2025 MHz) and 2.4 GHz WLAN (2400–2484 MHz). The measured return loss of the proposed antenna has a good value of approximately 27.2 dB at 2.4 GHz WLAN. The antenna’s peak gains also have a high value of 1.92 dBi at 2 GHz and 2.12 dBi at 2.45 GHz. The proposed antenna shows omnidirectional radiation patterns over the entire frequency range of interest.