Abstract
In this paper, a microstrip antenna for RF sensor is proposed. This proposed antenna is the FM-CW radar device using orthogonal linear polarizations. The proposed sensor antenna is composed of the antenna elements and a slot ring mixer. The antenna elements can be shared for transmitting and receiving wave. In the slot ring mixer, the transmitting wave and the receiving wave are multiplied and a beat frequency output is obtained. As the proposed sensor antenna is contracted using Both-side microwave technology and the mixer is arranged in the same plate, the structure is very simple and compact. The characteristics of the sensor antenna are investigated.
