Abstract: A variable resistor and a digital-to-analog converter are provided. The variable resistor includes a main resistor, a plurality of switches, and a plurality of redundancy resistors. The switches are respectively constituted by a plurality of non-volatile memory cells. The switches are coupled to the main resistor. The redundancy resistors are respectively coupled to the main resistor through the switches.

Abstract: A calibration apparatus includes a calibration circuit and a singularity detection (SD) circuit. The calibration circuit performs a calibration process upon a time-interleaved analog-to-digital converter (TI-ADC) with a plurality of TI channels, wherein the calibration process includes detecting and correcting mismatch between different TI channels of the TI-ADC. The SD circuit sets an SD flag by evaluating variation of statistical characteristics of an ADC input signal between different TI channels of the TI-ADC, and outputs the SD flag to the calibration circuit, wherein the calibration circuit controls the calibration process according to the SD flag.

Abstract: A radar system includes an ultrasonic radar unit and a warning device. The ultrasonic radar unit is configured to be detachably mounted on a vehicle, and is configured to output a pairing signal when a pairing function is activated and output a warning signal upon detecting an object that is within a range. The warning device is configured to be electrically connected to the ultrasonic radar unit and to be mounted inside the vehicle. The warning device is configured to wirelessly communicate with the ultrasonic radar unit to receive the warning signal and the pairing signal; when receiving the pairing signal, couple the ultrasonic radar unit to one of a plurality of warning areas that is on the warning device according to the pairing signal; control one of the warning areas that is coupled to the ultrasonic radar unit to output a visual warning upon receiving the warning signal.

Abstract: The grating layer of a surface emitting laser is divided into a first grating region and a second grating region along a horizontal direction. The second grating region is located at a middle area of the grating layer, while the first grating region is located in an outer peripheral area of the grating layer. Each of the first and second grating regions comprises a plurality of micro-grating structures. The grating period of the micro-grating structures in the first grating region is in accordance with the following mathematical formula: ? = m ? ? 2 * n eff ; in addition, the grating period of the micro-grating structures in the second grating region is in accordance with the following mathematical formula: ? = o ? ? 2 * n eff . Wherein, ? is the length of grating period, ? is the wavelength of the laser light, neff is the equivalent refractive index of semiconductor waveguide, m=1, and o=2.

Abstract: The disclosure is a multi-axis radar system that includes a base, a first control module, a second control module, and a waveguide. The first control module includes a horizontal rotatable azimuth elevation axis device, an S-band single-channel rotary connector, and a spin ring. In contrast, the second control module includes a vertical rotatable axis device and an X-band single-channel rotary connector. The waveguide is composed of four portions, each with its axis. The first and second portions are inside the cylindrical body of the base, and the third portion is coaxially arranged with the second control module. The fourth portion is outside the multi-axis radar system. The disclosure includes a broadband bipolar mmWave antenna consisting of two substrates, a parasitic element, a patch, and two feeding lines. The system is designed for efficient radar operation and precise data collection.

Abstract: The grating layer of a surface emitting laser is divided into a first grating region and a second grating region along a horizontal direction. The second grating region is located at a middle area of the grating layer, while the first grating region is located in an outer peripheral area of the grating layer. Each of the first and second grating regions comprises a plurality of micro-grating structures. The grating period of the micro-grating structures in the first grating region is in accordance with the following mathematical formula: ? = m ? ? 2 ? n eff ; in addition, the grating period of the micro-grating structures in the second grating region is in accordance with the following mathematical formula: ? = o ? ? 2 ? n eff . Wherein ? is the length of grating period, ? is the wavelength of the laser light, neff is the equivalent refractive index of semiconductor waveguide, m=1, and o=2.

Abstract: A screw hole position detecting apparatus is applied to a board body and at least one screw. The board body defines at least one screw hole. The screw hole position detecting apparatus includes a microprocessor, a lamp group and a camera. The lamp group is configured to illuminate the board body. The camera is configured to photograph the board body to obtain an original image and transmit the original image to the microprocessor. The microprocessor is configured to grayscale convert the original image into a grayscale image, and to convert the grayscale image into a binarization image based on a threshold value. Based on the binarization image, whether the at least one screw hole is locked into the at least one screw is determined.

Abstract: A semiconductor laser epitaxial structure includes a horizontal cavity configured to generate an optical field distribution, a grating layer located within the optical field distribution, a first semiconductor optical amplifier disposed between a light-emitting surface of the semiconductor laser epitaxial structure and the horizontal cavity, and a first tunnel junction layer disposed between the horizontal cavity and the first semiconductor optical amplifier. The grating layer is configured to convert a horizontal light to a vertical light. The semiconductor laser epitaxial structure does not require alignment, the yield rate of manufacturing the semiconductor laser is increased, and the manufacturing cost and manufacturing processes can be reduced.

Abstract: The grating layer of a surface emitting laser is divided into a first grating region and a second grating region along a horizontal direction. The second grating region is located at a middle area of the grating layer, while the first grating region is located in an outer peripheral area of the grating layer. Each of the first and second grating regions comprises a plurality of micro-grating structures. The grating period of the micro-grating structures in the first grating region is in accordance with the following mathematical formula: ? = m ? ? 2 * n eff ; in addition, the grating period of the micro-grating structures in the second grating region is in accordance with the following mathematical formula: ? = o ? ? 2 * n eff . Wherein, ? is the length of grating period, ? is the wavelength of the laser light, neff is the equivalent refractive index of semiconductor waveguide, m=1, and o=2.

Abstract: The grating layer of a surface emitting laser is divided into a first grating region and a second grating region along a horizontal direction. The second grating region is located at a middle area of the grating layer, while the first grating region is located in an outer peripheral area of the grating layer. Each of the first and second grating regions comprises a plurality of micro-grating structures. The grating period of the micro-grating structures in the first grating region is in accordance with the following mathematical formula: ? = m ? 2 ? n e f f ; in addition, the grating period of the micro-grating structures in the second grating region is in accordance with the following mathematical formula: ? = O ? 2 ? n e f f . Wherein, ? is the length of grating period, ? is the wavelength of the laser light, neff is the equivalent refractive index of semiconductor waveguide, m=1, and o=2.

Abstract: An antenna board alignment method includes following steps: A microprocessor finds a central positioning point on an antenna board to locate a positioning rectangle. The microprocessor finds four inner positioning points on the positioning rectangle to locate the antenna board. The microprocessor finds a plurality of outer positioning points at a plurality of edge locations on the antenna board to locate at least one edge of the antenna board.

Abstract: Provided is a semiconductor laser diode including multiple active layers and a grating layer. The semiconductor laser diode includes two (or more than two) active layers, a grating layer, and a tunnel junction. The grating layer and the tunnel junction are provided between the two active layers. The tunnel junction is electrically connected to the two active layers, and the two active layers share and are optically coupled to the grating layer, thereby improving the external quantum efficiency and slope efficiency of the semiconductor laser diode.

Abstract: The grating layer of a surface emitting laser is divided into a first grating region and a second grating region along a horizontal direction. The second grating region is located at a middle area of the grating layer, while the first grating region is located in an outer peripheral area of the grating layer. Each of the first and second grating regions comprises a plurality of micro-grating structures. The grating period of the micro-grating structures in the first grating region is in accordance with the following mathematical formula: ? = m ? ? 2 * n eff ; in addition, the grating period of the micro-grating structures in the second grating region is in accordance with the following mathematical formula: ? = o ? ? 2 * n eff . Wherein, ? is the length of grating period, ? is the wavelength of the laser light, neff is the equivalent refractive index of semiconductor waveguide, m=1, and o=2.

Abstract: A structure of distributed feedback (DFB) laser includes a grating layer having a phase-shift grating structure and a gratingless area. In addition, both side-surfaces of the DFB laser are coated with anti-reflection coating to improve SMSR and to obtain good slope efficiency (SE). The grating layer is divided by the phase-shift grating structure in a horizontal direction into a first grating area and a second grating area adjacent to a laser-out surface of the DFB laser. The phase-shift grating structure provides a phase-difference distance, such that a shift of phase exists between the micro-grating structures located within the first grating area and the other micro-grating structures located within the second grating area. The gratingless area located within the second grating area contains no micro-grating structure, and moreover, the gratingless area will not change the phase of the micro-grating structures located within the second grating area.

Abstract: An edge-emitting laser having a small vertical emitting angle includes an upper cladding layer, a lower cladding layer and an active region layer sandwiched between the upper and lower cladding layers. By embedding a passive waveguide layer within the lower cladding to layer, an extended lower cladding layer is formed between the passive waveguide layer and the active region layer. In addition, the refractive index (referred as n-value) of the passive waveguide layer is larger than the n-value of the extended lower cladding layer. The passive waveguide layer with a larger n-value would guide the light field to extend downward. The extended lower cladding layer can separate the passive waveguide layer and the active region layer and thus expand the near-field distribution of laser light field in the resonant cavity, so as to obtain a smaller vertical emitting angle in the far-field laser light field.

Abstract: A structure of distributed feedback (DFB) laser includes a grating layer having a phase-shift grating structure and a gratingless area. In addition, both side-surfaces of the DFB laser are coated with anti-reflection coating to improve SMSR and to obtain good slope efficiency (SE). The grating layer is divided by the phase-shift grating structure in a horizontal direction into a first grating area and a second grating area adjacent to a laser-out surface of the DFB laser. The phase-shift grating structure provides a phase-difference distance, such that a shift of phase exists between the micro-grating structures located within the first grating area and the other micro-grating structures located within the second grating area. The gratingless area located within the second grating area contains no micro-grating structure, and moreover, the gratingless area will not change the phase of the micro-grating structures located within the second grating area.

Abstract: An edge-emitting laser having a small vertical emitting angle includes an upper cladding layer, a lower cladding layer and an active region layer sandwiched between the upper and lower cladding layers. By embedding a passive waveguide layer within the lower cladding to layer, an extended lower cladding layer is formed between the passive waveguide layer and the active region layer. In addition, the refractive index (referred as n-value) of the passive waveguide layer is larger than the n-value of the extended lower cladding layer. The passive waveguide layer with a larger n-value would guide the light field to extend downward. The extended lower cladding layer can separate the passive waveguide layer and the active region layer and thus expand the near-field distribution of laser light field in the resonant cavity, so as to obtain a smaller vertical emitting angle in the far-field laser light field.

Abstract: An edge-emitting laser having a small vertical emitting angle includes an upper cladding layer, a lower cladding layer and an active region layer sandwiched between the upper and lower cladding layers. By embedding a passive waveguide layer within the lower cladding layer, an extended lower cladding layer is formed between the passive waveguide layer and the active region layer. In addition, the refractive index (referred as n-value) of the passive waveguide layer is larger than the n-value of the extended lower cladding layer. The passive waveguide layer with a larger n-value would guide the light field to extend downward. The extended lower cladding layer can separate the passive waveguide layer and the active region layer and thus expand the near-field distribution of laser light field in the resonant cavity, so as to obtain a smaller vertical emitting angle in the far-field laser light field.