抄録
In this study, a Voltage Controlled Oscillator (VCO), used in our Wireless Communication System, was designed using Quality Engineering Techniques by identifying the VCO's basic function. Traditionally, during the design stage, the VCO's have been evaluated by measuring the frequency selectivity and output power under oscillating conditions. These types of characteristics, are referred to as "objective quality characteristics" and are not recommended to be used. Instead, the basic function was evaluated in a non-oscillating condition. The DC signal from the power supply and the feed back AC signal are supplied to the transistor. These signals were put to the oscillation circuit and produced the output in the form of complex numbers. The results were analyzed by the signal-to-noise ratio in the Hermitean Form. The result was a stabilized VCO performance and a high reproducibility of the improvements and conclusions were confirmed.
