Title:
DIGITAL FREQUECY SYNTHESIZER
Document Type and Number:
Japanese Patent JPH02295225
Kind Code:
A
Abstract:
PURPOSE: To perform speedy frequency switching by providing a multiple feedback loop frequency synthesizer to which a reference frequency signal having a frequency larger than a desired frequency difference brought from the synthesizer is inputted. CONSTITUTION: An indirect digital frequency synthesizer 100 includes two feedback loops, i.e., phase-locked loops PLL1 and PLL2 here to which two reference frequency signals having frequencies fR1 and fR2 are inputted through each signal lines 106 and 108. The digital frequency synthesizer 100 can output one output signal selected among plural adjacent frequency difference to an output port 110 within a specific frequency band and such frequency difference is smaller than the frequencies fR1 and fR2 of the two reference frequency signals. Consequently, each feedback loop can widen the bandwidth, shorten the frequency switching time, and suppress the noise.
Inventors:
ZUBI GARANI
JIYON EI CHIIZA
REIMONDO SHII UOOTAAMAN JIYUNI
JIYON EI CHIIZA
REIMONDO SHII UOOTAAMAN JIYUNI
Application Number:
JP10151290A
Publication Date:
December 06, 1990
Filing Date:
April 17, 1990
Export Citation:
Assignee:
RAYTHEON CO
International Classes:
H03L7/16; H03L7/22; H03L7/23; (IPC1-7): H03L7/16; H03L7/22
Domestic Patent References:
| JPS5023266A | 1975-03-12 | |||
| JPS63234724A | 1988-09-30 |
Attorney, Agent or Firm:
Kyozo Yuasa (4 outside)