A compact, symmetric U-shaped monopole for ultra wide band operation

A novel design of an ultra wide band U-shaped monopole is presented and discussed. The antenna has a unique design consisting of a U shape with 2 additional arcs fed by a 50Ω microstrip feed. The antenna is low profile and has overall dimensions 30mm×30mm×1.5mm, which is compact in size for portable UWB applications. The simulated results show that the antenna has operating bandwidth (2.4-11.4GHz), satisfying the condition for ultra-wide band operation. The antenna exhibits band notch properties, and is able to prevent interference with the 5.2/5.8GHz WLAN and 5.5GHz WiMAX bands by varying the length of a small rectangle in the antenna structure. The symmetrical geometric structure of the antenna provides omnidirectional radiation patterns. The design criteria of this antenna as well as the outcome of the experimental results are presented in this paper. The antenna is fabricated and the return loss measured using a vector network analyzer. The measured and simulated results are in good agreement.