A new concept of continuous-time narrow bandpass Q-varying filter with transient suppression

In many applications, it is required to have continuous-time narrow (single-frequency) bandpass filters which simultaneously possess a very selective magnitude response (high quality factor Q) and a transient response of short duration. However, increasing the quality factor also increases the duration of the transient response exhibited by the filter at is output to a given stimulus. This paper presents a theoretical concept of a new class of continuous-time narrow bandpass filters whose quality factor changes with time. Owing to a temporary change in the value of the quality factor, the duration of the transient behavior can be considerably reduced. Simulations verifying the effectiveness of the proposed Q-varying bandpass filter are presented and compared to the performance of a traditional bandpass filter with no variations in time of its quality factor.