Digital tuning of continuous-time high-Q filters

A digital tuning scheme for automatic tuning of continuous-time high-Q filters is proposed. The tuning scheme uses the phase information for both frequency and Q factor tuning; therefore the relationship between the filter´s passband magnitude and Q is immaterial. Due to the digital control of tuning loops, only one loop is active at a given time interval, which eliminates the need for slow Q tuning loop, improves stability and reduces tuning time. Experimental tests on the breadboard verify the operation where approximately 1% tuning error is accomplished.