This paper presents a novel, highly compact capacitive shunt RF MEMS switch. In the presented configuration interdigitation of signal lines with actuation electrodes is considered. The compactness has been achieved further by incorporating HfO2 a high-k dielectric material in place of traditionally used SiO2. The capacitive overlap area reduces by 70%, leading to the overall reduction of about 15% in the switch size. Switch with HfO2 optimized for X - band shows-56.78 dB isolation and - 0.058 dB insertion loss at 10 GHz as compared to the -40.8 dB isolation, -0.1 dB insertion loss for the switch with SiO2. Significant improvement in switching time is also observed. Pull-in voltage of 5.6V is obtained at a gap of 1um between bridge and transmission line. The compact switch can be useful for the future communication applications.