Active integrated radiator for microwave sensing system

The design and test of an active integrated radiator (AIR) which is suitable for use in phased arrays and spatial power combining are described. The circuit is constructed by using a removed-lateral-shell dielectric resonator (DR) to serve as a radiator and a resonator, with a BJT transistor as the active device. The high-Q DR is small in size and acts as a frequency selective element in the active radiator, and provides the high frequency stability and low phase noise (-90 dBc/Hz) characteristic. The performance of the DR radiator is discussed. This kind of active radiator can be used in a remote control system and a miniature Doppler radar system, particularly, in low microwave frequency band(<1 GHz)