DC offset filter for wide band beamforming receivers

摘要

A DC offset filter for wide band beamforming receivers is disclosed. In an exemplary embodiment, an apparatus includes a first mixer configured to down-convert an RF wideband beamformed signal to generate a first baseband wideband beamformed signal, the RF wideband beamformed signal having a beam pattern selected from a plurality of beam patterns, and a notch filter configured to remove DC offset from the first baseband wideband beamformed signal independent of the beam pattern.

主权项

1. An apparatus comprising:
a first mixer configured to down-convert an RF wideband beamformed signal to generate a first baseband wideband beamformed signal, the RF wideband beamformed signal having a beam pattern selected from a plurality of beam patterns; a DC blocking capacitor connected between an output of the first mixer and an input of a baseband filter, the DC blocking capacitor forming a notch filter that is configured to remove DC offset from the first baseband wideband beamformed signal independent of the beam pattern selection; a bypass switch connected across the DC blocking capacitor configured to operate in a bypass mode to bypass the DC blocking capacitor and to operate in a non bypass mode to enable the DC blocking capacitor to remove the DC offset; and a loopback switch configured to loop back RF wideband transmit signal to the input of the first mixer; wherein the apparatus is configured to:
close the bypass switch and the loopback switch and perform a first DC offset measurement;open the bypass switch and perform a second DC offset measurement;set the bypass switch based on the first DC offset measurement and the second DC offset measurement; andopen the loopback switch.