Multiplier device with suppression of higher-order distortion

Abstract

A multiplier device is configured to include first to n^th multipliers M₁ to M_n for multiplying a carrier modulated information signal with first to n^th mutually phase shifted and identical, substantially square wave mixing signals MS₁ to MS_n with 50% duty cycle. In order to eliminate fifth or higher order interferences from the output of the multiplier device according to the invention, n is greater than 2, outputs of the multipliers M₁ to M_n are respectively coupled through weighting circuits W₁ to W_n with respective fixed weighting factors WF₁ to WF_n to an adder circuit, the mixing signals MS₁ to MS_n having respective phase angles φ_i corresponding to φ_i=i*Δφ, the weighting factors WF_i corresponding to the sine value of the respective phase angles φ_i=i*Δφ with Δφ being the mutual phase difference between each two phase consecutive mixing signals corresponding to π/(n+1) and i varying from 1 to n.

Description

[0001]This application is a continuation of U.S. patent application Ser. No. 10 / 581,659, filed 31 May 2006, and claims the benefit of PCT / EP2004 / 013742, filed 1 Dec. 2004 and EP 03078812, filed 5 Dec. 2003.BACKGROUND AND SUMMARY OF THE INVENTION[0002]The invention relates to a multiplier device comprising first to nth multipliers M1 to Mn for multiplying a carrier modulated information signal with first to nth mutually phase shifted and identical, substantially square wave mixing signals MS1 to MSn with 50% duty cycle. Such multiplier devices are frequently used in receivers for converting an RF antenna input signal with an RF carrier frequency fRF into an intermediate frequency (IF) signal with an IF carrier frequency fIF and / or for demodulating an (IF) carrier modulated information signal with carrier frequency fc into baseband, or as used in stereo decoder circuits for decoding and / or demultiplexing a stereo multiplex signal into left and right baseband stereo signals.[0003]A ste...

AI Technical Summary

Benefits of technology

[0007]It is an object of the present invention to provide a robust, low cost multiplier device allowing for an effective suppression of all undesired higher order interferences, which is ve

Problems solved by technology

However, due to the ongoing demand for higher performance/price ratio the suppression of third order interferences as provided for in the above known multiplier device does not suffice anymore.

At frequencies increasi

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