Wideband phase shift circuit for IQ modulator

摘要

The circuit includes two phase shifter branches in parallel. The phase shifter of one branch (1) is controlled based on the input signal frequency, so that the phase angle between the two output signals corresponds roughly to the desired value (coarse control). The phase shifter of the other branch (5) is controlled to the desired phase angle (fine control) via a phase detector (15) connected between the outputs of the two branches.