Abstract: This study presents the application of RF MEMS based switches in tunable bandpass filter operating in the wireless X-band. The filter is designed on 635 μm-thick high-resistivity silicon substrate which is compatible with the new SiGe process. The design and simulation are performed using 3D full wave electromagnetic simulator IE3D. Tuning is achieved by the Metal-Air-Metal (MAM) based fixed-fixed beam shunt switches, which present variable capacitances along the lines of a parallel coupled bandpass filter, thereby tuning the filter center frequency by 3% between 9.8 to 10.1 GHz. The simulated filter occupies a chip area of 11.8x4.2 mm2 and achieved an insertion loss of only 0.7 dB over the frequency range of 8-11.4 GHz and return loss of less than -10 dB throughout the operation band. This filter is widely used today in radar, satellite and terrestrial communications and electronic countermeasure applications, both militarily and commercially.