Quantum MMIC (QMMIC) VCO's for Wireless Applications

The monolithic integration of heterostructure tuneling diodes with other semiconductor devices, such as HFET's, creates novel, quantum functional devices and circuits. The enhanced functionality of these devices enables design of both digital and analog circuits with reduced complexity, smaller size and better performance. Several types of QMMIC VCO's operating in L-band frequency range have been designed and characterized. VCO's achieved output power of 8-10 dBm at L-band frequency range. All VCO's exhibited very low phase noise (in the range of -107 to -115 dBc/Hz) at 1.0 MHz away from the carrier frequency. In this paper we discuss the design and fabrication of various types of QMMIC VCO's. DC and RF characteristics and a comprehensive large signal model of a tunnel diode incorporated in the harmonic balance analysis of circuits are discussed. The design and simulation of different types of VCO's and experimental results of these VCO's are then presented.