Methods and apparatus for signal filtering

摘要

Systems and techniques for filtering of radiofrequency signals. A plurality of tunable cross-couple resonators are connected using capacitive coupling elements to form a cross-coupled bandpass filter. A center frequency of the filter may be set based on frequencies of the resonators and a fractional bandwidth of the filter may be set based on states of the capacitive coupling elements. Programmable zeroes of the filter may be set based on states of reactive elements coupling selected pairs of the resonators. The reactive elements may be capacitive, for zeroes below the center frequency, or inductive, for zeroes above the center frequency.

主权项

1. An apparatus comprising:
a cross-coupled bandpass filter characterized by a tunable center frequency, tunable fractional bandwidth and one or more programmable transmission zeroes, wherein one of the programmable transmission zeroes is maintained at DC and one of the programmable transmission zeroes is maintained at an infinite frequency.