Integrated phase locked loop local oscillator

A dual-conversion super heterodyne receiver, comprising:

• a radio frequency (RF) amplifier;
• a first mixer coupled to an output of the RF amplifier for providing a first intermediate frequency output;
• a phase locked loop (PLL) including a voltage controlled oscillator (VCO) with an output connected to the first mixer, a numerical counter and a phase-frequency detector for comparing an output of said numerical counter to a reference frequency for phase locked loop operation;
• a divide by seven and one-half pulse-swallowing counter having an input connected to the PLL and a second local oscillator output for deriving a second local oscillator frequency one seven and a half part of said first local oscillator frequency;
• a second mixer having respective inputs connected to receive said first intermediate frequency from said first mixer and a second local oscillator signal from said second local oscillator output for providing an output for a second intermediate frequency;
• and
• an output stage with low-pass filtering and automatic gain control connected to said second intermediate frequency output of the second mixer.

A phase locked loop (PLL), comprising:

• a voltage controlled oscillator (VCO) with an astable multivibrator including a pair of cross-coupled amplification transistors provided for oscillator gain and a pair of feedback transistors each having its base tied to its emitter provided for capacitive positive feedback and respectively connected between the base of a first one and collector of a second one of said cross-coupled amplification transistors, wherein semiconductor process variations in the Miller capacitance of said amplification transistors is self-corrected by matching variations in the capacitance of said feedback transistors;
• a numeric counter means connected to divide down a sample of an output frequency produced by the VCO;
• and
• a phase-frequency detector connected to compare an output of the numeric counter to an externally provided reference frequency and connected to lock an operating frequency of the VCO to said reference frequency.