| A MEMS based microstrip phase shifter is proposed in this Thesis. The proposed phase shifter is a micro-spring supported membrane, which is fabricated inside an aperture in the ground plane beneath a microstrip transmission line. Apertures are first fabricated in the ground plane beneath the transmission line, forming a defected structure. A micro-spring supported rectangular membrane is fabricated within each aperture of the defected ground structure. This membrane is smaller than the aperture, and so a thin double-C shaped slot surrounds the copper membrane around its perimeter. Slot dimensions and effective permittivity of the material between the ground and the signal line define a static phase shift from a normally continuous ground plane. Analog phase shift control is achieved by electrostatically actuating the flexible membrane away from the transmission line. Thereby, a variation in the size of the defected ground slot, a decrease in the effective permittivity, and so phase shift, is achieved. (Abstract shortened by UMI.)... |
