Title:
FM HIGH FREQUENCY TRANSMITTER
Document Type and Number:
Japanese Patent JP2570987
Kind Code:
B2
Abstract:
PURPOSE: To correct the nonlinearity of a modulation characteristic of a voltage controlled oscillator in the FM high frequency transmitter sending an FM repetitive waveform with a voltage controlled oscillator using a varactor diode.
CONSTITUTION: A frequency multiplier 1 receiving a sine wave at its terminal 6 provides an output of a voltage comprising a fundamental wave and harmonics of the received sine wave and band pass filters 21, 22, 23, 24 pass only a predetermined frequency component of the voltage. Variable attenuators 31, 32, 33, 34 attenuate an amplitude of a voltage for each frequency component by a predetermined attenuation and variable phase shifters 42, 43, 44 shift the phase of the voltage of each frequency component by a predetermined deviation and they are superimposed and the result is fed to a terminal 7 of a VCO 5 as a control voltage.
Inventors:
KANEKO TOMOYA
Application Number:
JP25642093A
Publication Date:
January 16, 1997
Filing Date:
September 20, 1993
Export Citation:
Assignee:
NIPPON ELECTRIC CO
International Classes:
H04B1/04; (IPC1-7): H04B1/04
Domestic Patent References:
| JP61103361A | ||||
| JP5291977A |
Attorney, Agent or Firm:
Hiroo Suzuki