Patent application number | Description | Published |
20090237285 | DIGITAL TO ANALOG CONVERTER SPUR CANCELLATION - A device includes an upsampling digital-analog converter (DAC) and logic to add a DC offset to a signal input to the DAC, the logic adapted to set the DC signal to cancel a DAC output spur. | 09-24-2009 |
20090237767 | PREDISTORTION USING FPGA - Predistortion logic for an optical communications laser or optical modulator, includes predistortion logic embodied in a field programmable gate array (FPGA). A first analog to digital converter (ADC) provides a representation of an RF signal at an input of the FPGA. A digital to analog converter provides a representation of an output of the FPGA to a laser or modulator. | 09-24-2009 |
20120213515 | SERVICE GROUP AGGREGATION - Methods and systems for aggregating service groups are provided. A chain of fiber nodes in a DOCSIS system is formed to aggregate the service groups served by the fiber nodes to form a super-service group. Multiple channels of a multiplexed data stream are used to transmit the signals from the super-service group. By creating a chain of fiber nodes and using multiple channels to transmit the signals from the super-service group, a DOCSIS system can be more efficiently reconfigured to segment a super-service group once the system has become exhausted. | 08-23-2012 |
20130004173 | OVERLAY SYSTEM WITH DIGITAL OPTICAL TRANSMITTER FOR DIGITIZED NARROWCAST SIGNALS - Methods and apparatuses are provided to modify existing overlay system architectures in a cost effective manner to meet the growing demand for narrowcast services and to position the existing overlay systems for additional future modifications. The implementations of the improved overlay system of this disclosure re-digitize narrowcast analog signals after they have been QAM modulated and upconverted to RF frequencies and replace the analog narrowcast transmitters with digital narrowcast transmitters. In the fiber nodes, the received narrowcast signals are converted back to analog signals and combined with analog broadcast signals for transmission to the service groups. | 01-03-2013 |
20130071120 | DIGITIZER FOR USE IN AN OVERLAY SYSTEM WITH DIGITAL OPTICAL TRANSMITTER FOR DIGITIZED NARROWCAST SIGNALS - Methods and apparatuses are provided to digitize an analog multi-channel RF narrowcast signal in an overlay system by dividing the signal into a plurality of subband signals and digitizing each subband signal using practical A/D converters. | 03-21-2013 |
20150050025 | Digitized Broadcast Signals - Methods, systems, and computer-readable media can facilitate digitizing a broadcast transmission and transporting the digitized broadcast transmission along with one or more digitized narrowcast transmissions to a subscriber. In embodiments, a digitized broadcast transmission and one or more digitized narrowcast transmissions can be separately demodulated and the transmissions can be combined at one or more receiving nodes. In embodiments, a digitized broadcast transmission can be combined with one or more digitized narrowcast transmissions. Lossless compression and de-compression techniques can be used to optimally transport digitized broadcast and narrowcast signals. | 02-19-2015 |
Patent application number | Description | Published |
20110129213 | METHOD AND APPARATUS FOR MEASURING A FACTOR CHARACTERIZING A BALANCED DETECTION DEVICE - A method is provided for measuring a factor, called herein the single-port rejection ratio (SPRR), characterizing a balanced detection device. The SPRR is representative of the ratio of the weak differential output current measured under illumination of a single-port of the balanced detection device to the strong measurable differential output current obtained under dual-port illumination. An apparatus for measuring the SPRR is also provided. | 06-02-2011 |
20120063474 | Low White Frequency Noise Tunable Semiconductor Laser Source - A low white frequency noise tunable semiconductor laser source is presented. The laser source includes a single-mode semiconductor laser assembly which generates a laser beam having a tunable frequency over a spectral range of interest. An optical filter is provided in the path of the laser beam. The optical filter has multiple spectral features distributed over the entire spectral range of interest. Each spectral feature has a narrow spectral range. A locking mechanism is further provided and is controllable for locking a spectral alignment between the frequency of the laser beam and any selected one of the spectral features of the optical filter. | 03-15-2012 |
20130022316 | Fiber Coupling Technique on a Waveguide - An optical coupling assembly for coupling light from an optical fiber including an angled tip into a planar waveguide via a waveguide coupling element is provided. In one embodiment, the optical fiber extends along the planar waveguide with the angled tip positioned such that light propagating in the optical fiber is coupled by the waveguide coupling element to propagate in the planar waveguide in counter propagation with respect to a fiber propagation direction. In another embodiment, the optical fiber includes a tapered peripheral portion tapering toward the angled tip and is disposed over the planar waveguide with the tapered peripheral portion extending therealong such that light propagating in the optical fiber is coupled to propagate in the planar waveguide with either forward or counter propagation. Embodiments of the present invention may be part of various photonic integrated circuits and may be manufactured more easily than known optical coupling assemblies. | 01-24-2013 |
20130188918 | Double Cladding Silicon-on-Insulator Optical Structure - A SOI optical structure is provided, including a succession of a substrate, insulator layer, patterned silicon layer and first and second cladding layer. In one embodiment the substrate is made of silicon, the insulator layer and first cladding are made of silicon oxide, and the second cladding layer is made of silicon nitride. The double cladding configuration provides both light confinement within the waveguides defined by the patterned silicon layer and optical isolation, for example from metal absorption when the optical structure is metallized. The double cladding configuration may also help reducing stresses within the optical structure. | 07-25-2013 |
20130188971 | COMPACT POLARIZATION-INSENSITIVE OPTICAL RECEIVER - A polarization-insensitive optical receiver for demodulating a phase-modulated input optical signal is provided. The optical receiver includes successively a polarization splitter, a first and second interferometric modules including respective delay lines, and a plurality of detectors. The input optical signal is split into two substantially orthogonally-polarized components, which are launched along respective optical paths into the corresponding interferometric modules where they demodulated and subsequently recombined prior to being detected by the plurality of detectors. Advantageously, the optical receiver allows mitigating undesired discrepancies between the optical paths traveled by the two polarization components by arranging the respective delay lines of the interferometric modules into intertwined spiraling structures. A waveguide assembly including a substrate and a pair of waveguides on the substrate and defining intertwined spiraling structures is also provided, as well as a waveguide coupling assembly for coupling, onto a same detector, two optical signals travelling along two parallel coplanar waveguides. | 07-25-2013 |
20140153862 | POLARIZATION ROTATOR ASSEMBLY INCLUDING A SUBWAVELENGTH COMPOSITE PORTION - A polarization rotator assembly for rotating a polarization mode of an electromagnetic signal is provided. The polarization rotator assembly has a waveguiding structure of co-extensive first and second layers defining, successively, an input portion, a subwavelength composite portion and a polarization rotating portion. The subwavelength composite portion is formed by the first and second layers, where the second layer defines a subwavelength pattern. The polarization rotator portion is geometrically configured to rotate the polarization mode of the electromagnetic signal. | 06-05-2014 |