Zero if frequency-modulator

An arrangement for frequency-modulating telecommunication carriers with baseband signals, comprising

• means for generating two quadrature-related baseband signals in two separate channels, each of said quadrature-related baseband signals being a sinusoidal function of the instantaneous angle of a message signal to be transmitted, including
• a voltage-controlled oscillator operative for issuing an output signal in dependence on an input voltage level,
• means for issuing two quadrature-related sinusoidal baseband reference waveforms,
• means for forming a correction signal proportionate to the phase difference between said output signal of said voltage-controlled oscillator and one of said quadrature-related sinusoidal baseband reference waveforms, and
• means for feeding said correction signal and the message signal to said voltage-controlled oscillator to establish said input voltage level;
• and
• means for producing a frequency-modulated carrier from said quadrature-related baseband signals, including
• means for providing two quadrature-related carrier-frequency waveforms,
• means for individually mixing one of said quadrature-related carrier-frequency waveforms with one of said quadrature-related baseband signals in one of said channels and the other carrier frequency waveform with the other of said baseband signals in the other channel to form respective first and second signals in said one and other channels, and
• means for combining said first and second signals from said channels into a single frequency-modulated carrier-frequency output signal.

An arrangement for generating quadrature-related baseband signals in two separate channels for use in frequency-modulating telecommunication carriers, comprising

• a voltage-controlled oscillator operative for issuing an output signal in dependence on an input voltage level;
• means for issuing two quadrature-related sinusoidal baseband reference waveforms;
• means for forming a correction signal proportionate to the phase difference between said output signal of said voltage-controlled oscillator and one of said quadrature-related sinusoidal baseband reference waveforms;
• and
• means for feeding said correction signal and a message signal to said voltage-controlled oscillator to establish said input voltage level.

An arrangement for producing a frequency-modulated telecommunication carrier from two quadrature-related baseband signals being respective in-phase and quadrature functions of a message signal to be transmitted and conveying information in two separate channels as to the modulation and deviation frequency components required for the frequency modulation, comprising

• means for providing two quadrature-related carrier-frequency waveforms;
• means for individually mixing one of said quadrature-related carrier-frequency waveforms with one of said quadrature-related baseband signals in one of said channels and the other carrier-frequency waveform with the other of said baseband signals in the other channel to form respective first and second signals in said one and other channels;
• and
• means for combining said first and second signals from said channels into a signle frequency-modulated carrier-frequency output signal.

A method of frequency-modulating telecommunication carriers with baseband signals, comprising the steps of

• generating two quadrature-related baseband signals being respective in-phase and quadrature functions of the instantaneous phase of a message signal to be transmitted;
• conveying the quadrature-related baseband signals in separate channels;
• providing two quadrature-related carrier-frequency waveforms;
• individually mixing one of the quadrature-related carrier-frequency waveforms with one of the quadrature-related baseband signals in one of the channels and the other carrier-frequency waveform with the other baseband signals in the other channel to form respective first and second signals in the one and the other channel, respectively;
• and
• combining the first and second signals from the channels into a single frequency-modulated carrier-frequency output signal.

A method of frequency-modulating telecommunication carriers with baseband signals, comprising the steps of

• generating two quadrature-related baseband signals each being a sinusoidal function of the instantaneous phase of a massage signal to be transmitted, including
• issuing an oscillating output signal having a frequency dependent on an output voltage level,
• producing two quadrature-related sinusoidal baseband reference waveforms,
• forming a correction signal proportionate to the phase difference between the oscillating output signal and one of the quadrature-related sinusoidal baseband reference waveforms,
• and utilizing the correction signal and the message signal to establish the input voltage level;
• conveying the quadrature-related baseband signals in separate channels;
• providing two quadrature-related carrier-frequency waveforms;
• individually mixing one of the quadrature-related carrier-frequency waveforms with one of the quadrature-related baseband signals in one of the channels and the other carrier-frequency waveform with the other baseband signal in the other channel to form respective first and second signals in the one and the other channel, respectively;
• and
• combining the first and second signals from the channels into a single frequency-modulated carrier-frequency output signal.