Tunable planar inverted-F antenna using rf MEMS switch for the reduction of human hand effect

In this paper, the tunable PIFA for the correction of impedance mismatch due to human hand effect has been developed. Metal-to-metal direct contact type RF MEMS switch has been used for tuning the resonance frequency of the capacitor loaded PIFA, which is piezoelectrically actuated with low actuation voltage. The characteristics of the tunable PIFA have been measured in the presence of phantom hand in order to show the feasibility for the correction of resonance frequency shift by the human hand effects. When the switch is in the on state, the resonant frequency of the PIFA shifted from 762 MHz to 690 MHz attributed to the phantom hand effect. By changing the switch status to the off state, the PIFA recovers its original resonant frequency with the phantom hand. The measured resonant frequency of the PIFA in the switch off state is 760 MHz with the phantom hand and the return loss at the resonant frequency is -22 dB.