Micro Electro Mechanical Systems (MEMS)

Liquid Level Sensor and RF Phase Shifter
Today the drive to innovate is stronger than ever. Novel technologies and applications are spreading across all fields of science. Consequently, expectations and needs for engineering applications have increased tremendously, and the prospects of Micro & Smart technologies to achieve them are very promising. The technology referred to by the terms ‘Micro & Smart systems’ is multidisciplinary and has generated a great deal of interest in the chemical, mechanical, electrical engineering, medical, materials science, and food science communities in recent years. MEMS promises to revolutionise nearly every product category by bringing together silicon based microelectronics with micromachining technology, making possible the realisation of complete ‘Systems-on-a-chip’.

MEMS is an enabling technology which allows the development of smart products, augmenting the computational ability of microelectronics with perception and control capabilities of micro sensors and micro actuators and expanding the space of possible designs and applications.

A phase shifter is a two-port network with the provision of phase difference between output and input signals which can be controlled by a control signal, usually DC bias. Phase shifters with low insertion loss, low drive power, continuous tunability and low production cost are the key to the development of lightweight phased array antennas.

3 D model of a typical RF phase shifter

MEMS components have demonstrated exceptional performance at RF and millimetre wave frequencies, including low insertion loss, high isolation and low drive power. The MEMS phase shifter can be configured to generate phase shift by loading Coplanar Waveguide (CPW) capacitively using a beam/bridge. The phase shifter with switched line approach has MEMS Switches in the configuration which in turn affects the overall RF performance of phase shifter, whereas the DMTL phase shifter can be optimized to achieve low Insertion Loss over wide frequency band. RF MEMS phase shifter for Ku-band Applications is designed using Distributed MEMS Transmission Line approach to achieve the phase shifting. The activity involved device development using silicon or quartz substrate and developing a development board for application development using COTS MEMS sensors.

MEMS devices on 4 inch Wafer

MEMS Development Unit