Modulation of an RF transmit signal

A circuit operative to modulate oscillation frequency of a transmit signal, the circuit comprising:

• a control block adapted to dynamically modulate a generated signal;
• a filter adapted to modify a biasing voltage applied to a first terminal of a transistor in response to variations in the generated signal;
• a pulse generator adapted to generate a pulse signal in response to detection of a transition of an oscillating signal;
• said transistor adapted to generate a radio frequency signal in response to receipt of a low-to-high or high-to-low transition of the generated pulse;
• an RC filter adapted to filter out high frequency components of the modulated signal;
• an amplifier adapted to generate the biasing signal in response to receipt of the filtered modulated signal at its positive input terminal, wherein a negative input terminal of the amplifier is coupled to an output terminal of the amplifier;
• and
• an oscillator adapted to generate the oscillating signal,
• wherein the generated signal is modulated by varying a value of a register disposed in the control block,
• wherein said control block is a commercially available microcontroller, and
• wherein a gate terminal of said transmit transistor is coupled to the ground potential.

A method of modulating an oscillation frequency of a transmit signal, the method comprising:

• modulating a generated signal dynamically;
• varying a biasing signal in response to modulation of the generated signal;
• applying the biasing signal to a first terminal of a transmit transistor;
• generating a pulse in response to detection of a transition of a clock signal;
• applying the generated pulse to a second terminal of the transmit transistor to generate a radio frequency burst at a harmonic of the frequency of the generated pulse in response to a low-to-high or high-to-low transition of the generated pulse, wherein voltage of the biasing signal selects the harmonic of the frequency of the generated pulse.

A method of modulating an oscillation frequency of a transmit signal, the method comprising:

• modulating a generated signal dynamically;
• varying a biasing signal in response to modulation of the generated signal;
• applying the biasing signal to a first terminal of a transmit transistor;
• generating a pulse in response to detection of a transition of a clock signal;
• and
• applying the generated pulse to a second terminal of the transmit transistor;
• filtering out high frequency components of the modulated signal;
• amplifying the filtered out modulated signal to generate the biasing signal;
• varying a register value for modulate the generated signal:
• and
• coupling a gate terminal of said transmit transistor to the ground potential.