摘要:
A quadrature modulator divides a first signal input as a local signal into an I channel signal and a Q channel signal orthogonal to each other and outputs a second signal having a desired phase delay corresponding to direct current voltages as for the first signal by giving the direct current voltages Vi and Vq to the I channel signal and the Q channel signal, respectively. A phase comparison unit detects a phase difference θ between the first signal and the second signal. A setting unit sets the desired phase delay. A controller section controls the direct current voltages supplied to the I channel signal and the Q channel signal respectively in the quadrature modulator so that an output value corresponding to the phase difference θ detected by the phase comparison unit is equal to a value corresponding to the desired phase delay set by the setting unit, and controls the direct current voltages to be the direct current voltages Vi and Vq satisfying the relation of Vi=cos θ and Vq=sin θ.
摘要:
A quadrature modulator divides a first signal input as a local signal into an I channel signal and a Q channel signal orthogonal to each other and outputs a second signal having a desired phase delay corresponding to direct current voltages as for the first signal by giving the direct current voltages Vi and Vq to the I channel signal and the Q channel signal, respectively. A phase comparison unit detects a phase difference θ between the first signal and the second signal. A setting unit sets the desired phase delay. A controller section controls the direct current voltages supplied to the I channel signal and the Q channel signal respectively in the quadrature modulator so that an output value corresponding to the phase difference θ detected by the phase comparison unit is equal to a value corresponding to the desired phase delay set by the setting unit, and controls the direct current voltages to be the direct current voltages Vi and Vq satisfying the relation of Vi=cos θ and Vq=sin θ.
摘要:
A digital signal offset adjusting apparatus has a capacitor causing an output terminal to pass a high frequency band of an input digital signal. A first coil has one end connected to an input terminal and a second coil has one end connected to an output. An operational amplifier has an input connected to another end of the first coil, a second input connected to a direct current voltage generator and an output connected to another end of the second coil. The operational amplifier outputs a signal obtained by subtracting and combining the low frequency band, the direct current component and a direct current bias voltage. A frequency characteristic compensating circuit is connected between a reference point and the second input of the operational amplifier. The gain of the operational amplifier increases with a component having a higher frequency from among low frequency bands of the input digital signal.
摘要:
A digital signal offset adjusting apparatus has a capacitor (21) causing an output terminal (20b) to pass through a high frequency band of an input digital signal in order to transmit a wideband digital signal without generating a waveform distortion, a first coil (23), one end of which is connected to an input terminal (20a), the first coil passing a low frequency band and a direct current component to another end, a second coil (22), one end of which is connected to an output end, a operational amplifier (31a), a first input end of which is connected to the other end of the first coil, a second input end of which is connected to a direct current voltage generator (25), an output end of which is connected to the other end of the second coil, the operational amplifier outputting to another end of the second coil a signal obtained by subtracting and combining the low frequency band, the direct current component and a direct current bias voltage, and a frequency characteristic compensating circuit (35) connected between a reference electrical potential point and the second input end of the operational amplifier, the compensating circuit being adopted to compensate for a frequency characteristic so that a gain of the operational amplifier increases with a component having a higher frequency from among low frequency bands of the input digital signal passed to the other end of the first coil.
摘要:
It is an object of the present invention to provide a data signal generating apparatus which is small in size, and can output the serial data in a desired sequence without assuming an indefinite state as well as being capable of dealing with the jitter measurement. In the data signal generating apparatus according to the present invention, synchronization means 25 for synchronizing a data output unit 11 with a multiplexer 13 has a phase comparator 16 for comparing the phase of a data synchronization clock signal outputted from a data output unit 11 in synchronization with the timing to update parallel data, with the phase of a divided clock signal A produced by dividing the frequency of a reference clock signal CK1 by a plural number “m” in the multiplexer 13, the signal A being used for determining the timing to performing parallel-serial conversion, a variable delay device 30 for adding a desired delay to a data request signal A′, the variable delay device 30 being constituted by an orthogonal modulation type delay device, and a control unit 26 for controlling a direct control signal to be inputted into the variable delay device 30 on the basis of a comparing result obtained from the phase comparator 16 to synchronize the timing to have the data output unit 11 update the parallel data with the timing to have the multiplexer 13 perform parallel-serial conversion processing.
摘要:
It is an object of the present invention to provide a data signal generating apparatus which is small in size, and can output the serial data in a desired sequence without assuming an indefinite state as well as being capable of dealing with the jitter measurement. In the data signal generating apparatus according to the present invention, synchronization means 25 for synchronizing a data output unit 11 with a multiplexer 13 has a phase comparator 16 for comparing the phase of a data synchronization clock signal outputted from a data output unit 11 in synchronization with the timing to update parallel data, with the phase of a divided clock signal A produced by dividing the frequency of a reference clock signal CK1 by a plural number “m” in the multiplexer 13, the signal A being used for determining the timing to performing parallel-serial conversion, a variable delay device 30 for adding a desired delay to a data request signal A′, the variable delay device 30 being constituted by an orthogonal modulation type delay device, and a control unit 26 for controlling a direct control signal to be inputted into the variable delay device 30 on the basis of a comparing result obtained from the phase comparator 16 to synchronize the timing to have the data output unit 11 update the parallel data with the timing to have the multiplexer 13 perform parallel-serial conversion processing.
摘要:
It is an object of the present invention to provide a data signal generating apparatus which is small in size, and can output the serial data in a desired sequence without assuming an indefinite state as well as being capable of dealing with the jitter measurement. In the data signal generating apparatus according to the present invention, synchronization means 25 for synchronizing a data output unit 11 with a multiplexer 13 has a phase comparator 16 for comparing the phase of a data synchronization clock signal outputted from a data output unit 11 in synchronization with the timing to update parallel data, with the phase of a divided clock signal A produced by dividing the frequency of a reference clock signal CK1 by a plural number “m” in the multiplexer 13, the signal A being used for determining the timing to performing parallel-serial conversion, a variable delay device 30 for adding a desired delay to a data request signal A′, the variable delay device 30 being constituted by an orthogonal modulation type delay device, and a control unit 26 for controlling a direct control signal to be inputted into the variable delay device 30 on the basis of a comparing result obtained from the phase comparator 16 to synchronize the timing to have the data output unit 11 update the parallel data with the timing to have the multiplexer 13 perform parallel-serial conversion processing.
摘要:
A data signal generating apparatus with a data output unit for outputting m-bit parallel data and a data synchronization clock signal synchronized with the parallel data in response to a data request signal produced by dividing the frequency of a reference clock signal by “m.” An m:1 multiplexer for receiving the parallel data in response to a latch signal produced by dividing the frequency of the reference clock signal by “m,” and outputting, at a rate of the reference clock signal, data synchronization serial data. Synchronization means for comparing the phases of the data synchronization clock signal and the latch signal, for synchronizing the parallel data with the latch signal, and for producing a control signal, and which delays, on the basis of the control signal, the reference clock signal or a divided clock signal (dividing the frequency of the reference clock signal by “m” or less).
摘要:
The object of the present invention is to provide a data decision apparatus and an error measurement apparatus which can set the phase of the clock to the optimum state with respect to the data signal without continuously sweeping of the phase, and can keep the state for a long time. The data decision apparatus according to the present invention comprises a delay device (34) for delaying a data signal (Dc) outputted from a decision device (31) by one bit, a first phase detector (35) for detecting a phase difference between a data signal (Db) to be inputted to the decision device (31) and the data signal (Dc) outputted from the decision device (31), a second phase detector (36) for detecting a phase difference between the data signal (Dc) outputted from the decision device (31) and a data signal (Dd) outputted from the delay device (34), a third phase detector (37) for outputting a base voltage with respect to the output values of the first and second phase detectors (35 and 36), and a phase controller (38) for controlling a phase shift amount of a variable delay device (32) to equalize an output value (P1) of the first phase detector (35) to a center value between an output value (P2) of the second phase detector (36) and the base voltage (P3).
摘要:
The object of the present invention is to provide a waveform shaping device and an error measurement device which can perform a waveform shaping operation with the sufficient amplitude margin, even if the mark ratio of the inputted data signal is significantly varied and the amplitude of the inputted data signal is decreased. The waveform shaping device according to the present invention comprises a voltage detector (22) for detecting an inputted data signal (Da) to obtain an amplitude value and the center amplitude voltage of the inputted data signal (Da), a reference voltage generator (23) for generate the reference voltage corresponding to the center amplitude voltage, and a comparator (25) for comparing the inputted data signal (Da) with the reference voltage, and in which the waveform shaping device further comprises a correction information outputting section (27) for outputting correction information V on the basis of a mark ratio (M) and an amplitude of the inputted data signal (Da), the correction information V used to correct the center amplitude voltage detected by the voltage detector (22), and a correction section (28) correct the reference voltage or the inputted data signal to be inputted to the comparator (25) on the basis of the correction information (V).