摘要:
In a coherent optical receiver, sufficient demodulation becomes impossible and consequently receiving performance deteriorates if an interchannel skew arises, therefore, a coherent optical receiver according to an exemplary aspect of the invention includes a local light source; a 90-degree hybrid circuit; an optoelectronic converter; an analog-to-digital converter; and a digital signal processing unit, wherein the 90-degree hybrid circuit makes multiplexed signal light interfere with local light from the local light source, and outputs a plurality of optical signals separated into a plurality of signal components; the optoelectronic converter detects the optical signals and outputs detected electrical signals; the analog-to-digital converter quantizes the detected electrical signals and outputs quantized signals; and the digital signal processing unit includes a skew compensation unit for compensating a difference in propagation delay between the plurality of signal components, and a demodulation unit for demodulating the quantized signals.
摘要:
In a coherent optical receiver, sufficient demodulation becomes impossible and consequently receiving performance deteriorates if an inter-channel skew arises, therefore, a method for detecting inter-channel skew in a coherent optical receiver according to an exemplary aspect of the invention includes the steps of: outputting a plurality of optical signals separated into a plurality of signal components by making a test light from a test light source interfere with a local light from a local light source; detecting the optical signals and outputting detected electrical signals; quantizing the detected electrical signals and outputting quantized signals; performing a fast Fourier transform process on the quantized signals; and calculating a difference in propagation delay between the plurality of signal components on the basis of a plurality of peak values in the results of performing the fast Fourier transform process.
摘要:
In a coherent optical receiver, sufficient demodulation becomes impossible and consequently receiving performance deteriorates if an inter-channel skew arises, therefore, a coherent optical receiver according to an exemplary aspect of the invention includes a local light source, a 90° hybrid circuit, an optoelectronic converter, an analog to digital converter, and a digital signal processing unit; wherein the 90° hybrid circuit makes multiplexed signal light interfere with local light from the local light source, and outputs a plurality of optical signals separated into a plurality of signal components; the optoelectronic converter detects the optical signals and outputs detected electrical signals; the analog to digital converter quantizes the detected electrical signals and outputs quantized signals; the digital signal processing unit includes a skew compensation unit for compensating a difference in propagation delay between the plurality of signal components, and an FFT operation unit for performing a fast Fourier transform process on the quantized signals; and wherein the difference in propagation delay is calculated on the basis of a plurality of peak values with a central focus on one peak value in the results of performing the fast Fourier transform process.
摘要:
There is provided an insulated wire including a wire conductor and an insulation coating formed on the wire conductor by extrusion coating a resin composition. The resin composition is a mixture of a polyphenylene sulfide-based resin (A) and a polyamide-based resin (B), in which a ratio of parts by mass of the resin (B) to that of the resin (A), i.e. (B)/(A), is not less than 5/95 and not more than 30/70.
摘要:
In power line communications using carrier waves of high frequencies in the MHz range such as 2 to 30 MHz, when a coaxial cable for performing transmission of signals and a power line are signal-coupled using a capacitive signal coupling unit, even if an impedance matching circuit is installed in the capacitive signal coupling unit, we have found that leakage current of levels that cannot be neglected from leakage noise considerations flows through the outer sheath of the coaxial cable that transmits the signals, and, accordingly, leaking electromagnetic waves induced by the leakage current flowing through the coaxial cable due to impedance mismatch between the power line and the capacitive signal coupling unit are reduced by an impedance member showing high impedances at high frequencies in the MHz range.
摘要:
Certain embodiments provide methods for manufacturing camera module including arranging a camera module body in a first shield and forming a resin having a light shielding effect. The camera module body has: a sensor board which has a sensor unit; and an optical element which has a lens unit and a spacer. The process of arranging this camera module body in the first shield is a process of arranging the camera module body in the first shield such that a gap is formed between the camera module body and the first shield. The process of forming the resin having the light shielding effect is a process of forming the resin having the light shielding effect in the gap between the first shield and camera module body.
摘要:
In a solid-state image sensing device, a second substrate having transparency, including a via is placed on a solid-state image sensor having a pixel region and a logic region formed in a first substrate and in which a passive component electrically connected with the solid-state image sensor through the via is mounted on the second substrate. Thus, highly efficient location of passive components is attained for miniaturization.