Abstract
An ultra-wideband (UWB) printed antenna fed by balanced microstrip is proposed. This antenna is in the structure of symmetrical dipoles, each of which consists of 3 semicircular metal patches. The antenna has been simulated by CST MICROWAVE STUDIO (R) software and tested. Both the simulation and experimental results indicate that the proposed antenna obtains an ultra-wide bandwidth of 2.8-16.3 GHz, when VSWR is less than 2. The experimental results of the directional diagrams indicate that the proposed antenna acquires a balance feed within the whole working band. The analysis of the surface current on the radiators indicates that the proposed antenna has a radiation mode of standing wave current in low frequency and traveling wave current in high frequency. The length of the antenna on polarization direction is 0.315 times of the maximum working wavelength, which shows that the antenna is well miniaturized.