Adjustable balanced modulator

A balanced modulator comprising:

• a first non-linear device receiving a first local oscillator signal and receiving an input signal, the first non-linear device producing a first mixed signal;
• a first bias voltage terminal supplying a first bias voltage to the first non-linear device;
• a second non-linear device receiving a second local oscillator signal and receiving the input signal, the first local oscillator signal being substantially out of phase with the second local oscillator signal, the second non-linear device producing a second mixed signal;
• a second bias voltage terminal supplying a second bias voltage to the second non-linear device;
• a phase corrector coupled to the input signal and adapted to correct the phases of the input signals received by the first and second non-linear devices to be substantially in-phase;
• and
• a summer summing the first and second mixed signals to produce an output signal.

An adjustable balanced modulator comprising:

• a first non-linear device receiving a first local oscillator signal and receiving an RF input signal, the first non-linear device producing a first mixed signal;
• a first bias voltage terminal supplying a first adjustable bias voltage to the first non-linear device;
• a second non-linear device receiving a second local oscillator signal and receiving the RF input signal, the first local oscillator signal being substantially out of phase with the second local oscillator signal, the second non-linear device producing a second mixed signal;
• a second bias voltage terminal supplying a second adjustable bias voltage to the second non-linear device;
• an adjustable phase corrector coupled to the RF input signal and allowing correction so that the phases of the RF input signals received by the first and second non-linear devices are substantially in-phase;
• and
• a summer summing the first and second mixed signals to produce an output signal including two intermodulation product terms and a substantially suppressed RF input term, the first and second bias voltages adjusted to substantially equalize the levels of the product terms in the output signal.

A modulator comprising:

• a phase inverter receiving a first local oscillator signal and producing a second local oscillator signal that is substantially out of phase with the first local oscillator signal;
• a first transistor having source and drain terminals and first and second gate terminals, the first gate terminal of the first transistor being coupled to the phase inverter for receiving a first oscillator signal, the second gate terminal of the first transistor receiving an RF input signal, the first transistor outputting a first mixed signal on the drain of the first transistor;
• a first bias voltage terminal supplying a first bias voltage to the first gate of the first transistor;
• a second transistor having source and drain terminals and first and second gate terminals, the first gate terminal of the second transistor being coupled to the phase inverter for receiving a second oscillator signal, the second gate terminal of the second transistor receiving the RF input signal, the second transistor outputting a second mixed signal on the drain of the second transistor;
• a second bias voltage terminal supplying a second bias voltage to the first gate of the second transistor;
• a phase corrector coupled to at least one of the transistors and adapted to correct the phase of at least one of the RF input signals received by the first and second transistors;
• and
• a summer summing the first and second mixed signals to produce an output signal.

A method of modulation comprising the steps of:

• receiving a first local oscillator signal;
• generating a second local oscillator signal, the second local oscillator signal being 180 degrees out of phase with the first local oscillator signal;
• receiving an RF input signal;
• generating a first mixed signal based on the first local oscillator signal and the RF input signal;
• generating a second mixed signal based on the second local oscillator signal and the RF input signal;
• and
• adjusting the relative phases of the RF input signals used to generate the first or second mixed signals to be substantially in-phase.

A balanced modulator comprising:

• a first non-linear device receiving a first local oscillator signal and receiving an input signal, the first non-linear device producing a first mixed signal;
• a first bias voltage terminal supplying a first bias voltage to the first non-linear device;
• a second non-linear device receiving a second local oscillator signal and receiving the input signal, the second non-linear device producing a second mixed signal;
• a second bias voltage terminal supplying a second bias voltage to the second non-linear device;
• a phase corrector coupled to the first and second non-linear devices;
• and
• a summer summing the first and second mixed signals to produce an output signal.