Patent ID: 8274325
Filing Date: 2012-09-25
Classification: H03L

Abstract:
1. A loop filter for receiving an input signal indicative of a phase difference between a reference signal and a signal output by a signal generator and forming a control signal for controlling the signal generator in dependence thereon, the loop filter comprising a plurality of filter components that determine the frequency response of the filter, said filter components being arranged so that a first set of said components determines one or more zeros of the filter's frequency response and a second set of said components determines one or more poles of the filter's frequency response, each of said first and second sets of filter components being independent of the other such that the zero(s) and pole(s) of the filter's frequency response may be selected independently, wherein one or more of the filter components has a resistance and/or reactance that is adjustable such that the bandwidth of the loop filter may be dynamically tuned.