Compact and UWB microstrip-fed monopoles antenna

A compact and UWB microstrip-fed antenna using three monopoles is proposed. The wideband frequency response of the UWB antenna can be achieved by simply determining the resonance frequencies of the three monopoles. The simulated reflection coefficient is smaller than -10 dB from 3.2 to 10.6 GHz, corresponding to fractional bandwidth of 105.7%. Besides, the antenna shows an omni-directional radiation pattern, stable gain and high efficiency. In order to verify the simulation results, the antenna is fabricated and measured where the measurement results are in good agreement with the simulation results for both the reflection coefficient and the radiation pattern.