Frequency enhancement method applied to a CMOS RF simulated inductor BP filter

A new method for improving the frequency response of an all transistor simulated CMOS inductor bandpass filter is proposed. It is shown that a significant increase of the central frequency up to 800 MHz or even more can be obtained by introducing a supplementary resistor connected to the gate of one transistor. The method makes also use of negative resistances to compensate the inductor losses. Small signal models and limitations of the method are discussed. High quality factors are obtained without stability problems or extra power consumption. The simulations prove that the frequency enhancement depends on the particular configuration of the active inductor.