Patent ID: 6546060
Filing Date: 2003-04-08
Classification: H04L

Abstract:
A direct modulating frequency shift keying transmitter for multi channel access comprising:a phase lock loop frequency synthesizer; a lock-in detector for locking said synthesizer to an object frequency of a predetermined channel; a modulation signal generator for applying a modulation signal to a voltage controlled oscillator for direct modulation in said synthesizer; an ON/OFF control signal generator for generating an ON/OFF control signal to switch a transmitting power amplifier ON in response to said ON/OFF control signal so as to enable a transmission signal output from said voltage controlled oscillator through said transmitting power amplifier; and means for adding said ON/OFF control signal to said voltage controlled oscillator to cancel frequency deviation of said transmission signal, wherein said voltage controlled oscillator includes a variable capacity diode to which said modulation signal is applied and said ON/OFF control signal is applied through a resistor.