NOISE IN ACTIVE RESONATORS AND THE AVAILABLE DYNAMIC-RANGE

Active resonators used to make bandpass filters are shown to suffer from a fundamental deterioration in available dynamic range with increasing Q, which we show arises from the dissipation in the transistors simulating inductance or performing an equivalent function. An active resonator with Q > 1 may only attain a specified dynamic range with the use of a larger tuning capacitance Than its passive counterpart, and with a consequent larger lower dissipation at a given frequency of operation. This poses a serious limitation on the integrated circuit realization of high frequency filters with high Q poles.