FREQUENCY SYNTHESIZER AND METHOD OF DETERMINING CONTROL VALUE THEREOF

• Main Authors: HAYASAKA TAKESHI, SHIBATA KINYA
• Format: Patent
• Language: English
• Published: 10.09.2009
• Subjects: AUTOMATIC CONTROL, STARTING, SYNCHRONISATION, OR STABILISATIONOF GENERATORS OF ELECTRONIC OSCILLATIONS OR PULSES; BASIC ELECTRONIC CIRCUITRY; ELECTRICITY

PROBLEM TO BE SOLVED: To provide a frequency synthesizer which can obtain oscillation output with superior characteristics by optimizing a control voltage to be applied to a varicap during coarse adjustment to improve characteristics for actual use, and also to provide a method of determining a control value of the same. SOLUTION: The frequency synthesizer is equipped with a voltage-controlled oscillator 14, the oscillation frequency of which can be varied by means of a first variable capacitance section for coarse adjustment of the oscillation frequency and a second variable capacitance section for fine adjustment of the oscillation frequency; a PLL circuit 14 which controls the first and second variable capacitance sections to change the oscillation frequency of the voltage-controlled oscillator into a desired one; and a memory 13 for storing a control value for controlling the capacitance of the second variable capacitance section during the coarse adjustment. COPYRIGHT: (C)2009,JPO&INPIT