TRANSMITTER AND SEMICONDUCTOR INTEGRATED CIRCUIT AVAILABLE FOR IT
First Claim
1. A transmitter operable to synthesize amplitude and phase components, comprising:
- an amplitude-signal path along which the amplitude component is conveyed; and
a phase-signal path along which the phase component is conveyed,wherein the amplitude-signal path includes a digital-to-analog converter operable to respond the amplitude component, and a low-pass filter supplied with an output of the digital-to-analog converter,the phase-signal path includes a phase modulator operable to convert the phase component up into a radio frequency component,the amplitude-signal path further includes a delay-calibrating unit connected with an input of the digital-to-analog converter,in an operation of delay calibration, the delay-calibrating unit provides a test input signal to the input of the digital-to-analog converter on receipt of supply of the test input signal to an input thereof,in the operation of delay calibration, the delay-calibrating unit detects a delay of a test output signal coming out of an output of the low-pass filter with respect to the test input signal on receipt of supply of the test output signal, andin the operation of delay calibration, the delay-calibrating unit calibrates an amplitude signal delay from the input of the delay-calibrating unit to the output of the low-pass filter in the amplitude-signal path in response to the test output signal delay, whereby a difference between the amplitude signal delay and a phase signal delay of the phase modulator in the phase-signal path is reduced.
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Accused Products
Abstract
The transmitter synthesizes amplitude and phase components and calibrates a delay mismatch between amplitude and phase components with high accuracy at high speed. The transmitter has: a digital-to-analog converter (DAC) and a low-pass filter (LPF) in its amplitude-signal path; and a phase modulator operable to convert up a phase component into an RF component in its phase-signal path. In an operation of delay calibration, a test input signal is supplied to a delay-calibrating unit in the amplitude-signal path, and the delay-calibrating unit provides a test input signal to DAC. Then, LPF generates a test output signal. The delay-calibrating unit detects a delay of the test output signal relative to the test input signal, calibrates an amplitude signal delay in a range from the input of the delay-calibrating unit to the output of LPF, reduces the difference between amplitude and phase signal delays of the phase modulator in the phase-signal path.
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Citations
20 Claims
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1. A transmitter operable to synthesize amplitude and phase components, comprising:
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an amplitude-signal path along which the amplitude component is conveyed; and a phase-signal path along which the phase component is conveyed, wherein the amplitude-signal path includes a digital-to-analog converter operable to respond the amplitude component, and a low-pass filter supplied with an output of the digital-to-analog converter, the phase-signal path includes a phase modulator operable to convert the phase component up into a radio frequency component, the amplitude-signal path further includes a delay-calibrating unit connected with an input of the digital-to-analog converter, in an operation of delay calibration, the delay-calibrating unit provides a test input signal to the input of the digital-to-analog converter on receipt of supply of the test input signal to an input thereof, in the operation of delay calibration, the delay-calibrating unit detects a delay of a test output signal coming out of an output of the low-pass filter with respect to the test input signal on receipt of supply of the test output signal, and in the operation of delay calibration, the delay-calibrating unit calibrates an amplitude signal delay from the input of the delay-calibrating unit to the output of the low-pass filter in the amplitude-signal path in response to the test output signal delay, whereby a difference between the amplitude signal delay and a phase signal delay of the phase modulator in the phase-signal path is reduced. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A semiconductor integrated circuit available for a transmitter operable to synthesize amplitude and phase components, comprising:
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an amplitude-signal path along which the amplitude component is conveyed; and a phase-signal path along which the phase component is conveyed, wherein the amplitude-signal path includes a digital-to-analog converter operable to respond the amplitude component, and a low-pass filter supplied with an output of the digital-to-analog converter, the phase-signal path includes a phase modulator operable to convert the phase component up into a radio frequency component, the amplitude-signal path further includes a delay-calibrating unit connected with an input of the digital-to-analog converter, in an operation of delay calibration, the delay-calibrating unit provides a test input signal to the input of the digital-to-analog converter on receipt of supply of the test input signal to an input thereof, in the operation of delay calibration, the delay-calibrating unit detects a delay of a test output signal coming out of an output of the low-pass filter with respect to the test input signal on receipt of supply of the test output signal, and in the operation of delay calibration, the delay-calibrating unit calibrates an amplitude signal delay from the input of the delay-calibrating unit to the output of the low-pass filter in the amplitude-signal path in response to the test output signal delay, whereby a difference between the amplitude signal delay and a phase signal delay of the phase modulator in the phase-signal path is reduced. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification