Abstract

The present invention discloses a type of LNB frequency down conversion integrated circuit. The present invention frequency-down-converts the RF signal with the Quadrature local oscillation signal (LO) and Quadrature Mixer. Then the 90 degree phase-shifting of the quadrature intermediate frequency (IF) signal after mixed is done by the use of passive Polyphase filter. The present invention further discloses a LNB frequency down conversion chip, a LNB frequency down circuit adopting the LNB frequency down conversion chip circuit and a method of LBN frequency down. The invention ensures the elimination of the minor image signal and the realization of the minor image suppression function.

IPC Classes  ?

• H04B 1/10 - Means associated with receiver for limiting or suppressing noise or interference
• H04N 7/20 - Adaptations for transmission via a GHz frequency band, e.g. via satellite
• H04L 1/00 - Arrangements for detecting or preventing errors in the information received
• H03D 7/16 - Multiple frequency-changing
• H04H 40/90 - Arrangements characterised by circuits or components specially adapted for receiving specially adapted for broadcast systems covered by groups specially adapted for satellite broadcast receiving
• H03D 7/18 - Modifications of frequency-changers for eliminating image frequencies

Abstract

A Low Noise block (LNB) down conversion chip circuit is disclosed. The solution performs a down conversion on a radio frequency signal utilizing a quadrature local oscillation signal and a quadrature mixer, and then performs a 90 degrees phase shift on a mixed quadrature intermediate frequency signal utilizing a passive multiphase filter. A LNB down conversion chip, LNB down conversion circuit with the LNB down conversion chip circuit and LNB down conversion method are also disclosed. With this application, an image signal is filtered, and image signal suppression is implemented.

IPC Classes  ?

• H03D 7/18 - Modifications of frequency-changers for eliminating image frequencies