Integrated image reject mixer

A radiotelephone comprising:

• A) an antenna;
• B) an image reject mixer integrated onto a single integrated circuit, coupled to the antenna, having:
• 1) a local oscillator for producing a local oscillator signal;
• 2) a local oscillator phase shifting network, coupled to the local oscillator, for producing an in-phase local oscillator signal and a quadrature local oscillator signal from the local oscillator signal including:
• a) a first capacitor, coupled to the local oscillator;
• b) a first resistor, coupled to the local oscillator;
• c) a second capacitor, coupled to the first resistor;
• and
• d) a second resistor, coupled to the first capacitor and the second capacitor;
• 3) a phase detector, coupled to the local oscillator phase shifting network, for examining a phase of the in-phase local oscillator signal and a phase of the quadrature local oscillator signal and generating a control signal for adjusting the phase of the in-phase local oscillator signal and the phase of the quadrature local oscillator signal;
• and
• 4) an intermediate frequency phase shift network, coupled to the phase detector, for adjusting a phase of an in-phase intermediate frequency signal and a phase of a quadrature intermediate frequency signal in response to the control signal including:
• a) a first capacitor;
• b) a first resistor, coupled to the first capacitor;
• c) a second capacitor, coupled to the first resistor;
• and
• d) a second resistor, coupled to the first capacitor and the second capacitor;
• C) an audio speaker, coupled to the image reject mixer.

A method for image reject mixing comprising the steps of:

• producing a local oscillator signal;
• creating an in-phase local oscillator signal and a quadrature local oscillator signal from the local oscillator signal;
• examining a phase of the in-phase local oscillator signal and a phase of the quadrature local oscillator signal and generating a control signal for adjusting the phase of the in-phase local oscillator signal in relation to the phase of the quadrature local oscillator signal;
• and
• adjusting a phase of an in-phase intermediate frequency signal in relation to a phase of a quadrature intermediate frequency signal using the control signal.