Title:
FREQUENCY SYNTHESIZER
Document Type and Number:
Japanese Patent JPH09199943
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To realize feedback control of a phase noise of a VCO used for a frequency synthesis circuit employing the dual phase locked loop in the frequency hopping spread spectrum system and not directly depending on a loop band width of any phase locked loop. SOLUTION: In the frequency synthesizer employing two pulse swallow phase locked loops 12, 14 generating output frequencies with two reference frequency functions used for an input to phase locked loops in its synthesis configuration, the frequency of the synthesizer is increased by a step equal to a reference frequency difference of the two phase locked loops and each frequency output of the phase locked loops is increased by a larger step, and a phase noise of a voltage controlled oscillator(VCO) 2a of each loop is suppressed in an excellent way and quick signal synchronization is realized.
Inventors:
SANJIEI KATSURIA
Application Number:
JP21036796A
Publication Date:
July 31, 1997
Filing Date:
August 09, 1996
Export Citation:
Assignee:
AT & T CORP
International Classes:
H03L7/197; H03B21/00; H03K3/0231; H03K3/03; H03K23/66; H03L7/099; H03L7/22; H03L7/23; H03L7/193; (IPC1-7): H03B21/00; H03L7/197; H03L7/22
Attorney, Agent or Firm:
Masao Okabe (9 others)