An adjustable phase shifter generates a phase shifted reference signal by introducing a phase shift in a reference signal. A phase detector identifies a phase difference between the reference signal and the phase shifted reference signal. A control signal generator generates a plurality of control signals, each of which causes the adjustable phase shifter to adjust a magnitude of at least one component value in the adjustable phase shifter. The phase shift introduced by the adjustable phase shifter is based at least partially on the magnitude of the at least one component value in the adjustable phase shifter. The control signal generator also selects one of the control signals, where the selected control signal causes the adjustable phase shifter to produce the phase shifted reference signal such that the phase difference attains a specified value. The analog filter adjusts a magnitude of at least one component value in the analog filter based at least partially on the selected control signal.