Patent ID: 7084714

Claim:
Quadrature demodulator ( 10 ) comprising a first oscillator ( 11 ) and a second oscillator ( 12 ), wherein the first oscillator ( 11 ) comprises a feedback amplifier ( 13 , 15 ) and an integrator ( 14 , 16 ), an output of the feedback amplifier ( 13 , 15 ) is connected to an input of the integrator ( 14 , 16 ), and an output of the integrator ( 14 , 16 ) is connected to an input of the feedback amplifier ( 13 , 15 ), the first oscillator ( 11 ) has two stable states which alternate with one another in an oscillation period and a non-stable or regenerative state between the two stable states, and a separate excitation signal is fed to the first oscillator ( 11 ) in order to determine the point in time at which switching between the two stable states takes place, the second oscillator ( 12 ) is identical to the first oscillator ( 11 ), and the quadrature demodulator ( 10 ) further comprises first and second excitation means ( 17 , 18 ), respectively, which are equipped to derive an excitation signal for the second and the first oscillator ( 12 , 11 ), respectively, from an output signal from the first and the second oscillator ( 11 , 12 ), respectively, and wherein an input signal S i (t) is fed to the quadrature demodulator ( 10 ) by means of which a parameter of one of the elements of the first and the second oscillator ( 11 , 12 ) is influenced, the elements comprising the feedback amplifier ( 13 , 15 ), integrator ( 14 , 16 ) or excitation means ( 17 , 18 ), and a set of quadrature output signals I o , Q o is fed to the outputs of the respective one element that is associated with the influenced parameter.