Frequency Modulation Based on Two Path Modulation

摘要

A two path direct frequency modulation system is disclosed. The system includes a Varactor, a voltage-controlled oscillator (VCO) calibration capacitor bank including a first plurality of switchable capacitors, and a frequency deviation capacitor bank including a second plurality of switchable capacitors. The method includes switching on or off a number of the first plurality of switchable capacitors to obtain a desired frequency band and determining number of cycles within a first predetermined time to obtain a first count, switching on or off a number of the first plurality of switchable capacitors or of the second plurality of switchable capacitors to change the desired frequency band and determining number of cycles within a second predetermined time to obtain a second count, and modulating a data signal by switching on or off a switchable capacitors of the second plurality of switchable capacitors according to the first and the second count.