Frequency synthesizer having microcomputer supplying analog and digital control signals to VCO

A frequency synthesizer, comprising:

• (A) an oscillator for generating a desired output frequency and including:
• (1) coarse-tuning means having a first input for receiving a digital input signal and for selecting one of a plurality of frequency ranges;
• and
• (2) fine-tuning means having a second input for receiving an analog input signal and for applying said signal to a variable reactance component in a resonating circuit, for selecting a desired frequency within a selected frequency range;
• (B) a computer, including:
• (1) a storage device for storing said oscillator's characteristics in the form of a digital table of the input signals corresponding to a plurality of frequency values, each identified by digital data;
• (2) an input for receiving input data representing the desired oscillator frequency;
• and
• (3) signal generating means for generating, from said stored digital table and said input data, a digital signal indicating the frequency range of said desired oscillator frequency, and an analog signal indicating the specific oscillator frequency desired;
• (C) an electrical circuit for applying said generated digital signal to said first input of the oscillator to coarse-tune the oscillator with respect to the desired frequency, and said generated analog signal to said second input of the oscillator to fine-tune the oscillator with respect to the desired frequency;
• (D) a frequency measuring circuit for digitally measuring the actual output frequency of the oscillator and for outputting a signal corresponding thereto;
• and
• (E) a feedback circuit for feeding back to said computer the output signal from said frequency measuring circuit and for controlling, in response thereto, the digital and analog signals generated by said computer.