Optical transceiver having optical receiver with function to cancel noise originated to optical transmitter
AssigneeSumitomo Electric Industries, Ltd.
InventorShigeo Hayashi
Life of this patent
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Abstract
An optical transceiver is disclosed, in which a noise attributed to the large current switching in the optical transmitter and superposed on the signal line in the optical receiver is effectively eliminated. The optical transceiver includes a noise generator and a delay circuit. The noise generator generates a compensation signal from the input signal of the optical transmitter. The compensation signal, having the same waveform and the phase with the noise superposed on the signal line, is input in the main amplifier. Since the phase of noise is delayed by the delay circuit, the main amplifier may cancel the noise as the common mode noise.
Claims16
An optical transceiver for outputting a first optical signal by receiving a first electrical signal and outputting a second electrical signal by receiving a second optical signal, comprising:
- an optical transmitter including,
- an input terminal for receiving the first electrical signal,
- a light-emitting device for outputting the first optical signal corresponding to the first electrical signal,
- a delay circuit for delaying the first electrical signal, and
- a driver for receiving the delayed signal and for switching the light-emitting device in current mode by receiving the delayed signal;
- an optical receiver including,
- a receiving optical subassembly for converting the second optical signal into an electrical signal and outputting the electrical signal,
- a main amplifier for receiving the electrical signal from the receiving optical subassembly, and
- an output terminal for outputting the second electrical signal;
- and
- a noise generator for receiving the first electrical signal for generating a compensation signal to be fed to the main amplifier,
- wherein a noise generated by the switching of the driver and superposed on the electrical signal from the receiving optical subassembly is cancelled by the compensation signal output from the noise generator.
The optical transceiver according to clam 1,
- wherein the optical transmitter and the optical receiver have a common ground.
An optical transceiver for outputting a first optical signal by receiving a first electrical signal and outputting a second electrical signal by receiving a second optical signal, comprising:
- an optical transmitter including,
- an input terminal for receiving the first electrical signal,
- a light-emitting device for outputting the first optical signal corresponding to the first electrical signal,
- a delay circuit for delaying the first electrical signal, and
- a driver for receiving the delayed signal and for switching the light-emitting device in current mode by receiving the delayed signal;
- an optical receiver including,
- a receiving optical subassembly for converting the second optical signal into an electrical signal and outputting the electrical signal,
- a main amplifier, and
- an output terminal for outputting the second electrical signal;
- and
- a noise generator for receiving the first electrical signal for generating a compensation signal by a phase opposite to the switching of the driver,
- wherein the optical receiver includes an analog adder circuit for adding the compensation signal with the electrical signal and outputting an added signal to the main amplifier, and
- wherein a noise generated by the switching of the driver and superposed on the electrical signal from the receiving optical subassembly is cancelled by the compensation signal output from the noise generator.
Dependencies are inferred from the claim text.