60 GHz frequency generator incorporating third harmonic boost and extraction

An oscillator circuit, comprising:

• a pair of transistors for sustaining the oscillation of said oscillator circuit, said transistors each having a gate terminal and a drain terminal;
• a transformer comprising a primary winding and a secondary winding, said primary winding coupled to both said drain terminals of said transistors, said secondary winding coupled to both said gate terminals of said transistors;
• a first tunable capacitor coupled to said primary transformer winding;
• a second tunable capacitor coupled to said secondary transformer winding;
• wherein said oscillator exhibits a first input impedance magnitude peak at a fundamental frequency and a second input impedance magnitude peak at a third harmonic frequency;
• wherein Barkhausen criterion is satisfied at said fundamental frequency but not at said third harmonic frequency thereby said oscillator circuit has a single oscillation mode at said fundamental frequency;
• and
• wherein a gate waveform is combined with a drain waveform to perform active fundamental cancellation.

A millimeter wave (mm-wave) frequency generator circuit, comprising:

• a phase/frequency detector;
• a low pass filter coupled to said phase/frequency detector;
• an oscillator incorporating a transformer based LC tank circuit and coupled to said low pass filter, said oscillator operative to:
• generate an output signal having both fundamental and third harmonic components;
• boost the level of said third harmonic component;
• satisfy Barkhausen criterion at the fundamental frequency but not at the third harmonic frequency wherein said oscillator circuit has a single oscillation mode at said fundamental frequency;
• a power amplifier coupled to the output of said oscillator and adapted to receive as input the output signal from said oscillator, said power amplifier operative to substantially filter the fundamental component from said output signal while amplifying the third harmonic component thereof;
• and
• a frequency divider coupled to said oscillator and said phase/frequency detector.

A millimeter wave (mm-wave) frequency generator circuit, comprising:

• a phase/frequency detector;
• a low pass filter coupled to said phase/frequency detector;
• an oscillator incorporating a transformer based LC tank circuit and coupled to said low pass filter, said oscillator comprising:
• an active network having an input and an output, said active network operative to generate an active signal for sustaining the oscillation of said oscillator;
• said transformer based resonator differential tank circuit coupled to said active network and operative to generate a feedback signal coupled to said active network input;
• wherein said differential tank circuit has a first impedance magnitude peak at a fundamental frequency and a second impedance magnitude peak at a third harmonic frequency;
• wherein said oscillator satisfies Barkhausen criterion at the fundamental frequency but not at the third harmonic frequency so that said oscillator circuit has a single oscillation mode at said fundamental frequency;
• a power amplifier coupled to the output of said oscillator and adapted to receive as input an output signal from said oscillator, said power amplifier operative to substantially attenuate the fundamental component from said output signal while amplifying the third harmonic component thereof;
• and
• a frequency divider coupled to said oscillator and said phase/frequency detector.