Patent ID: 7136493
Filing Date: 2006-11-14
Classification: H04S

Abstract:
1. A sub-harmonic generator, comprising: an input band-pass filter operable to receive an input signal containing frequencies from among a first range and to produce a first intermediate signal containing frequencies from among a second range, wherein the band-pass filter includes a low pass filter having a first corner frequency and a high pass filter having a second corner frequency, the first corner frequency being greater than the second corner frequency, and the low pass filter is operable to receive the input signal and to produce a low pass signal, and the high pass filter is operable to receive the low pass signal and to produce the first intermediate signal; a signal divider circuit operable to receive the first intermediate signal and to produce a square wave signal containing square wave signal components at fundamental frequencies from among a third range, the third range of frequencies being about one octave below the second range of frequencies; a wave-shaping circuit operable to receive the square wave signal and to attenuate frequencies substantially outside the third range to produce a second intermediate signal containing sinusoidal signal components from among frequencies corresponding to the respective fundamental frequencies of the square wave signal components; an RMS detector operable to produce an RMS signal corresponding to an instantaneous amplitude of the first intermediate signal; and a voltage controlled amplifier operable to amplify the second intermediate signal by an amount proportional to the RMS signal to produce a sub-harmonic signal.