EXCITER AND QUADRATURE ERROR CORRECTION METHOD
First Claim
1. An exciter comprising:
- a sine wave generator configured to generate a first sine wave and a second sine wave having a phase different from the phase of the first sine wave by 90°
while changing a frequency in a predetermined step at a preset time interval;
a filter configured to store a plurality of filter coefficients, set one of the plurality of filter coefficients, and perform filter processing for the first sine wave and the second sine wave using the set filter coefficient;
a digital/analog converter configured to convert the first sine wave and the second sine wave after the filter processing into a first analog signal and a second analog signal, respectively; and
a quadrature modulator configured to quadrature-modulate the first analog signal and the second analog signal and generate a modulated signal according to the frequency at which the first sine wave and the second sine wave are generated.
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Abstract
According to one embodiment, an exciter comprises a sine wave generator, a filter, a digital/analog converter, and a quadrature modulator. The sine wave generator generates a first sine wave and a second sine wave while changing a frequency in a predetermined step at a preset time interval. The filter sets one of stored filter coefficients and performs filter processing for the first sine wave and the second sine wave. The digital/analog converter converts the first sine wave and the second sine wave after the filter processing into a first analog signal and a second analog signal, respectively. The quadrature modulator quadrature-modulates the first analog signal and the second analog signal.
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Citations
7 Claims
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1. An exciter comprising:
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a sine wave generator configured to generate a first sine wave and a second sine wave having a phase different from the phase of the first sine wave by 90°
while changing a frequency in a predetermined step at a preset time interval;a filter configured to store a plurality of filter coefficients, set one of the plurality of filter coefficients, and perform filter processing for the first sine wave and the second sine wave using the set filter coefficient; a digital/analog converter configured to convert the first sine wave and the second sine wave after the filter processing into a first analog signal and a second analog signal, respectively; and a quadrature modulator configured to quadrature-modulate the first analog signal and the second analog signal and generate a modulated signal according to the frequency at which the first sine wave and the second sine wave are generated. - View Dependent Claims (2, 3, 4)
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5. A quadrature error correction method comprising:
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generating a first sine wave and a second sine wave having a phase different from the phase of the first sine wave by 90°
while changing a frequency in a predetermined step at a preset time interval;performing filter processing for the first sine wave and the second sine wave using a filter coefficient set out of a plurality of filter coefficients stored in advance; converting the first sine wave and the second sine wave after the filter processing into a first analog signal and a second analog signal, respectively; quadrature-modulating the first analog signal and the second analog signal and generating a modulated signal according to the frequency at which the first sine wave and the second sine wave are generated; and outputting the modulated signal according to a plurality of frequencies to a spectrum analyzer. - View Dependent Claims (6, 7)
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Specification