An angle demodulator in which an FM modulated wave is converted into an IF signal (SI) in the form of digital so as the signal is supplied to a Hilbert transformer (81) and to an outer product calculation section (82). The Hilbert transformer (81) allows the phase of the IF signal (SI) to shift ninety...http://www.google.com.au/patents/US6611571?utm_source=gb-gplus-sharePatent US6611571 - Apparatus and method for demodulating an angle-modulated signal
