Scully, Scott, Murphy & Presser
FM demodulation circuit
 An FM demodulation circuit includes a phase conversion circuit which converts a frequency variation of an input signal into a phase variation and has a variable conversion characteristic, and a control current source circuit which outputs, when the level of the input signal drops lower than a predetermined level, control current to vary the conversion characteristic of the phase conversion circuit so that the demodulation sensitivity may be raised. 
NEC Corporation
H
H03D
inventional
Tomohiro
Fujii