Title:
ACOUSTIC FM TRANSMITTER
Document Type and Number:
Japanese Patent JP2015198282
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To provide a compact and inexpensive acoustic FM transmitter having high frequency control accuracy, by enabling FM modulation using a fractional-N type PLL circuit.SOLUTION: An acoustic FM transmitter 1 for transmitting an acoustic signal while performing analog FM modulation in a PLL modulation unit 8 includes a voltage-controlled crystal oscillator 8a performing output based on a reference signal by oscillation of an oscillator, a phase comparator 8b for converting the phase difference, between a signal from the voltage-controlled crystal oscillator 8a and a phase comparison signal inputted from a fractional-N type frequency divider 8e, into a voltage and outputting as a phase difference signal, a loop filter 8c, a voltage-controlled oscillator 8d, and the fractional-N type frequency divider 8e. The voltage-controlled crystal oscillator 8a outputs a FM modulation signal by performing analog FM modulation of the oscillation frequency of a reference signal by the acoustic signal.
Inventors:
KOIKE YUKINAGA
MIYASHITA YUICHI
MIYASHITA YUICHI
Application Number:
JP2014074100A
Publication Date:
November 09, 2015
Filing Date:
March 31, 2014
Export Citation:
Assignee:
CIRCUIT DESIGN KK
International Classes:
H04B1/04; H03C3/00; H03L7/08; H03L7/197
Attorney, Agent or Firm:
Tatsuya Saito