Dual resonant active internal antenna for FM radio reception in mobile phones

An on-ground internal antenna for FM radio reception in mobile phones is proposed and evaluated. By combining a parasitic loop radiator with a driven active monopole antenna, a dual resonant frequency response is achieved with an average effective antenna efficiency of −22.5 dB over the frequency band 88–108 MHz. The total volume of the antenna is 0.93 cm 3 with a height above ground of 4 mm. A comparison with the conventional solution of re-using the headset cord as the antenna is included.