FREQUENCY SYNTHESIZING DEVICE USING LOW PASSING PLL(PHASE LOCKED LOOP) IC INSIDE MOBILE COMMUNICATION TERMINAL

摘要

PURPOSE: A frequency synthesizing device using low passing PLL IC inside a mobile communication terminal is provided to decrease a locking time and improve quality such as phase noise and phase error and so on. CONSTITUTION: The frequency synthesizing device installs; a control unit(10) controlling an entire working; a fixed frequency generating unit(20) generating the fixed frequency for making a standard frequency of PLL IC down within 100MHz; a channel frequency generating unit(30) generating the channel frequency for transmitting; a local frequency generating unit(40) generating the local frequency for receiving; a first mixer(25) outputting the standard frequency within 100MHz to the channel frequency generating unit by mixing the channel frequency; and a second mixer(35) outputting the standard frequency within 100MHz to the local frequency generating unit by mixing the local frequency.