Harmonic reject mixer with active phase mismatch compensation in the local oscillator path

• US 8,461,901 B1
• Filed: 02/17/2012
• Issued: 06/11/2013
• Est. Priority Date: 02/17/2012
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Morton, Matthew A., Comeau, Jonathan P., Thoenes, Edward Wade
• Primary Examiner(s): LE, DINH THANH
• Application Number:
  US13/399,221
• Time in Patent Office: 480 Days
• Field of Search: 327335-361, 455/323, 455/326
• US Class Current: 327/355
• CPC Class Codes: H03D 2200/0086 Reduction or prevention of harmonic frequencies
• CPC Class Codes: H03D 7/1441 using field-effect transistors H03D7/145 takes precedence
• CPC Class Codes: H03D 7/1458 Double balanced arrangements, i.e. where both input signals are differential
• CPC Class Codes: H03D 7/1483 comprising components for selecting a particular frequency component of the output
• CPC Class Codes: H03D 7/165 at least two frequency changers being located in different paths, e.g. in two paths with carriers in quadrature combined with amplitude demodulation H03D1/2245, combined with angle demodulation H03D3/007; N-path filters H03H19/002

Abstract

A harmonic rejection mixer having a phase rotator fed by a local oscillator signal. The local oscillator signal has a reference frequency. The phase rotator produces a plurality of output signals, each one of the signals having a common frequency related to the reference frequency and having different relative phase shifts. A plurality of mixer sections, each one of the sections being fed an input signal and a corresponding one of the plurality of output signals mixes the local oscillator signal with the corresponding one of the plurality of output signals fed thereto. A combiner combines the mixer signal from the plurality of mixer sections into a composite output signal. A detector detects energy in a harmonic of the composite signal and for adjusting the output signal of the phase rotator to reduce the selected harmonic of the composite signal.

Claims

1. A harmonic rejection mixer, comprising:

a plurality of phase rotators fed by a common input local oscillator signal having a reference frequency, each one of the phase rotators separating the common local oscillator signal into a pair of channels with an in-phase signal in one of the channels having a ninety degree phase shift relative to a quadrature signal in the other one of the channels, each one of the channels providing a selected gain to the in-phase signal and quadrature signal therein and wherein the phase rotator combines the gain provided in-phase signal and quadrature signal to produce a composite local oscillator signal having a selected one of a plurality of phase shifts relative to the common input local oscillator signal; and

a plurality of mixer sections, each one of the mixer sections being fed the composite local oscillator signal of a corresponding one of the plurality of phase rotators and an input signal to translate the frequency of the input signal by a frequency related to the having a reference frequency of the local oscillator signal.

2. The harmonic rejection mixer recited in claim 1 including a detector for detecting energy in a harmonic of the translated signal and for adjusting the output signal of the phase rotator to reduce the selected harmonic of the translated signal.