Patent ID: 6046628
Filing Date: 2000-04-04
Classification: H04L

Abstract:
A demodulating device which comprises an orthogonal transforming circuit, an up-converting circuit, a pulse signal producing circuit, and a low-pass filter, said orthogonal transforming circuit being for orthogonally transforming a received frequency shift keying signal to produce a first base band signal and a second base band signal, said up-converting circuit being connected to said orthogonal transforming circuit and for mixing said first base band signal and said second base band signal to produce a mixed signal as an up-converted signal, said pulse signal producing circuit being connected to said up-converting circuit and for producing a pulse signal in response to said up-converted signal, said low-pass filter being connected to said pulse signal producing circuit for filtering said pulse signal to produce a filtered signal as a demodulated signal, said up-converting circuit comprising:a clock signal producing circuit for producing a clock signal having a uniform periodic cycle;a phase converting circuit connected to said clock signal producing circuit for converting said clock signal having the uniform periodic cycle to produce a first clock signal having a first phase and a second clock signal having a second phase;a first EXOR circuit connected to said orthogonal transforming circuit and to said phase converting circuit for receiving said first base band signal and said first clock signal to produce a first EXOR output signal;a second EXOR circuit connected to said orthogonal transforming circuit and to said phase converting circuit for receiving said second base band signal and said second clock signal to produce a second EXOR output signal; anda mixing circuit connected to said first EXOR circuit and to said second EXOR circuit for mixing said first EXOR output signal and said second EXOR output signal to produce said up-converted signal.