ABSTRACT
The RF sensors operates on Doppler principal. Under this scenario the efficient transceiving element is the key for its success in the detection of tiny human vital signs. Antenna is a device acting as a transition element between RF front end circuitry and free space. Further, it must be a low cost, compact and reliable structure. This section describes the state-of-the art in antenna design along with design and prototyping of various antenna structures useful as the transceiving element in the RF sensor.
