Patent ID: 6956380

Claim:
A narrow-band amplifier comprising a quadrature detector, integrators, and a vector modulator, said narrow-band amplifier resolving input signals into in-phase components and quadrature-phase components by means of said quadrature detector, integrating said in-phase components and said quadrature-phase components by means of said respective integrators, vector-modulating said integrated in-phase components and said integrated quadrature-phase components by means of said vector modulator, and outputting the vector signals; a first signal source which feeds a first sine-wave signal to said quadrature detector, a second signal source which feeds a first cosine-wave signal orthogonal with the first sine-wave signals to said quadrature detector, a third signal source which feeds a second sine-wave signal to said vector modulator, a fourth signal source which feeds a second cosine-wave signal orthogonal with the second sine-wave signals to said vector modulator, said first, second, third, and fourth signal sources are signal sources that numerically control the output signal frequency and phase by a controller, with the output signals being updated once their respective pre-determined wait times have passed after control by said controller, and said controller controls said first, second, third and fourth signal sources before the time when they are about to be synchronized by said pre-determined wait times so that the times when the output signals of said first, second, third, and fourth signal sources are updated are all synchronized.