Back to results
US 9,312,897 B2Granted
DC offset filter for wide band beamforming receivers
AssigneeQUALCOMM Incorporated
InventorsGregory Steele, Yossi Tsfati, Haim M Weissman, Mazhareddin Taghivand
Life of this patent
Estimating the term…
Abstract
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.
Claims10
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;
- and
- open the loopback switch.
8 more elements
An apparatus comprising:
- means for down-converting an RF wideband beamformed signal to generate a baseband wideband beamformed signal, the RF wideband beamformed signal having a beam pattern selected from a plurality of beam patterns;
- means for notch filtering to remove DC offset from the baseband wideband beamformed signal independent of the beam pattern selection;
- a bypass switch configured to selectively bypass the means for notch filtering during a bypass mode and for enabling the means for notch filtering to remove the DC offset;
- and
- a loopback switch configured to selectively providing a RF wideband transmit signal along with the RF wideband beamformed signal;
- means for closing the bypass switch and the loopback switch and performing a first DC offset measurement;
- means for opening the bypass switch and performing a second DC offset measurement;
- means for setting the bypass switch based on the first DC offset measurement and the second DC offset measurement;
- and
- means for opening the loopback switch.
7 more elements
Dependencies are inferred from the claim text.