FM demodulator using a single input signal
AssigneeIndustrial Technology Research Institute
InventorChing-Feng Lee
Life of this patent
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Abstract
A FM demodulator using a single input signal has two I-Q splitters with constant group delay apparatuses. During operation, t two I-Q splitters with constant group delay apparatuses may receive the input modulated signal to generate not only one pair of modulated and respectively delay τ1 and τ2 in phase signals but also another pair of modulated and respective delay τ1 and τ2 quadrature signals. These signals are used to demodulate the final demodulated signal.
Claims30
An FM demodulator using a single input signal apparatus, comprising:
- a first I-Q splitter with a constant group delay apparatus receiving the input signal to generate a first in phase output signal and a first quadrature output signal;
- a second I-Q splitter with a constant group delay apparatus receiving said first in phase output signal to generate a second in phase output signal and a second quadrature output signal;
- a first multiplier stage receiving said first in phase output signal and said second quadrature output signal to generate a first output signal;
- a second multiplier stage receiving said first quadrature output signal and said second in phase output signal to generate a second output signal;
- a differential stage receiving said first output signal and said second output signal to generate a third output signal;
- and
- a low pass filter receiving said third output signal to generate a demodulated signal.
A FM demodulator using a single input signal apparatus, comprising:
- a first I-Q splitter with constant group delay apparatus receiving an input signal to generate a first in phase output signal and a first quadrature output signal;
- a second I-Q splitter with a constant group delay apparatus receiving said first quadrature output signal to generate a second in phase output signal and a second quadrature output signal;
- a first multiplier stage receiving said first in phase output signal and said second quadrature output signal to generate a first output signal;
- a second multiplier stage receiving said first quadrature output signal and said second in phase output signal to generate a second output signal;
- a differential stage receiving said first output signal and said second output signal to generate a third output signal;
- and
- a low pass filter receiving said third output signal to generate a demodulated signal.
A demodulating method using a single input signal, comprising the steps of:
- using a first I-Q splitter with a constant group delay apparatus receiving the input signal to generate a first output signal and a second output signal;
- using a second I-Q splitter with a constant group delay apparatus receiving said first output signal to generate a third output signal and a fourth output signal;
- multiplying said first output signal by said third output signal to generate a fifth output signal;
- multiplying said second output signal by said fourth output signal to generate a sixth output signal;
- and
- subtracting from said sixth output signal and fifth output signal to generate a demodulating signal.
Dependencies are inferred from the claim text.