Title: Image rejection mixer and multiband generator
Application Number: 200410011825 Application Date: 2004.09.22
Publication Number: 1601891 Publication Date: 2005.03.30
Approval Pub. Date: Granted Pub. Date:
International Classifi-cation: H03D7/18
Applicant(s) Name: Sony Corp. Address:
Inventor(s) Name:
Attorney & Agent: dang jianhua
Abstract:
     The present invention suppresses a harmonic component without impairing the phase orthogonality of a pair of complex signals. A polyphase filter is configured so that K pieces of filter circuits, each of which comprises a resistor and a capacitor, are connected and 360/K degrees out of phase with a preceding one. Since counterclockwise rotation occurs when expression is given in terms of the complex plane, a notch occurs in a negative frequency region. A RC value is set so that a notch occurs in a specified frequency band to suppress a (4N-1)-order harmonic component. Since the polyphase filter has a symmetrical structure, an unbalanced component contained in an input signal is eliminated at a frequency that agrees with a pole determined by the RC value. This action improves the orthogonality.
Time: 10
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