Abstract: A novel frequency tunable bi-directional phased array processing consisting of variable phase shifting and amplitude adjustment which employs a vector modulator and active combiner and splitter is proposed. Advantages of the proposed bi-directional a phased array processing includes the following 1) compact size; 2) high efficiency; 3) reduced passive trace loss and power consumption; 4) active current combining; 5) high input-output isolation; 6) high resolution and precise gain control and unequal combining or splitting; 7) phase-invariant amplifier design; 8) high accuracy and high-resolution phase shifter; 9) frequency tunability, within a small frequency range and/or a large frequency range; and 10) optimal unequal combining or splitting.

Abstract: A wideband power amplifier (PA) linearization technique is proposed. A current interpolation technique is proposed to linearize power amplifiers over a wide bandwidth. The wideband power amplifier linearization technique employs a novel transconductance Gm linearizer using a current interpolation technique that achieves improvement in the third order intermodulation over wide bandwidth for a sub-micron CMOS differential power amplifier. By using a small amount of compensating bias into an opposite phase differential pair, linearization over wide bandwidth is achieved and can be optimized by adjusting the compensating bias.

Abstract: A wideband power amplifier (PA) linearization technique is proposed. A current interpolation technique is proposed to linearize power amplifiers over a wide bandwidth. The wideband power amplifier linearization technique employs a novel transconductance Gm linearizer using a current interpolation technique that achieves improvement in the third order intermodulation over wide bandwidth for a sub-micron CMOS differential power amplifier. By using a small amount of compensating bias into an opposite phase differential pair, linearization over wide bandwidth is achieved and can be optimized by adjusting the compensating bias.

Abstract: A method employs an unmanned aerial vehicle to carry an electromagnetic field measurement system to overcome environmental obstacles in measuring environmental electromagnetic field. The electromagnetic field measurement system senses the electromagnetic field of a spatial position in the environment to generate a sensing signal, then processes the sensing signal to remove the high-frequency electromagnetic interference generated by the operation of the unmanned aerial vehicle itself from the sensing signal, and converts the processed sensing signal into a digital signal. The digital signal is processed to extract at least one wave according to a fundamental frequency and a harmonic order, thereby removing the low-frequency electromagnetic interference from the digital signal. The extracted wave is employed in calculating an environmental electromagnetic field value of the spatial location.

Abstract: A method employs an unmanned aerial vehicle to carry an electromagnetic field measurement system to overcome environmental obstacles in measuring environmental electromagnetic field. The electromagnetic field measurement system senses the electromagnetic field of a spatial position in the environment to generate a sensing signal, then processes the sensing signal to remove the high-frequency electromagnetic interference generated by the operation of the unmanned aerial vehicle itself from the sensing signal, and converts the processed sensing signal into a digital signal. The digital signal is processed to extract at least one wave according to a fundamental frequency and a harmonic order, thereby removing the low-frequency electromagnetic interference from the digital signal. The extracted wave is employed in calculating an environmental electromagnetic field value of the spatial location.

Abstract: A method for extracting rivet points in large scale three-dimensional point cloud based on deep learning is provided. Geometric attribute scalar of a point cloud of aircraft skin is calculated point by point, and the scalar attribute domain is mapped to the two-dimensional image to obtain a two-dimensional attribute scalar map of the point cloud. The 2D attribute scalar map is processed using a convolutional neural network and the probability that each point belongs to a rivet point is calculated. The rivet point cloud is divided through a threshold according to the probability; and the point clouds belonging to a same rivet is clustered from the divided rivet point cloud using Euclidean cluster.

Abstract: A method for measuring a seam on aircraft skin based on a large-scale point cloud is disclosed. A point cloud density of each point in an aircraft skin point cloud is calculated. Seam and non-seam point clouds are divided according to a discrepancy of the calculated point cloud density. A point is selected from the point cloud of the seam area, and a section at the point is extracted. A certain range of the seam and non-seam point clouds is projected to the section and a projected point cloud is acquired. A calculation model of flush and gap is constructed, and the flush and the gap of the aircraft skin seam at the measuring point is calculated according to the projected point cloud and the calculation model.

Abstract: A wideband tunable frequency single-subband converter is proposed. The wideband frequency tunable converter operates within a wideband and tunable frequency range, and has process, voltage, and temperature (PVT) tracking capability. In one embodiment, the wideband converter comprises a frequency tunable polyphase filter having a plurality of switchable polyphase resistors. The polyphase resistors are controlled by a frequency tuning control signal to achieve wideband frequency tunability. In a preferred embodiment, a triode mode transistor is used as a polyphase resistor, and a different resistance value of the polyphase filter is realized by turning on one or multiple of the different transistors in triode mode. In addition, a constant Gm(R) bias generator is used to provide the gate biases to the triode mode transistors to maintain a constant and stable resistance value across PVT and other variation.

Abstract: A method for measuring a seam on aircraft skin based on a large-scale point cloud is disclosed. A point cloud density of each point in an aircraft skin point cloud is calculated. Seam and non-seam point clouds are divided according to a discrepancy of the calculated point cloud density. A point is selected from the point cloud of the seam area, and a section at the point is extracted. A certain range of the seam and non-seam point clouds is projected to the section and a projected point cloud is acquired. A calculation model of flush and gap is constructed, and the flush and the gap of the aircraft skin seam at the measuring point is calculated according to the projected point cloud and the calculation model.

Abstract: A method for extracting rivet points in large scale three-dimensional point cloud based on deep learning is provided. Geometric attribute scalar of a point cloud of aircraft skin is calculated point by point, and the scalar attribute domain is mapped to the two-dimensional image to obtain a two-dimensional attribute scalar map of the point cloud. The 2D attribute scalar map is processed using a convolutional neural network and the probability that each point belongs to a rivet point is calculated. The rivet point cloud is divided through a threshold according to the probability; and the point clouds belonging to a same rivet is clustered from the divided rivet point cloud using Euclidean cluster.

Abstract: A wideband power amplifier (PA) linearization technique is proposed. A current interpolation technique is proposed to linearize power amplifiers over a wide bandwidth. The wideband power amplifier linearization technique employs a novel transconductance Gm linearizer using a current interpolation technique that achieves improvement in the third order intermodulation over wide bandwidth for a sub-micron CMOS differential power amplifier. By using a small amount of compensating bias into an opposite phase differential pair, linearization over wide bandwidth is achieved and can be optimized by adjusting the compensating bias.

Abstract: A method for rapid analysis of tunnel section convergence including: S obtaining a three-dimensional point cloud of tunnel structure; S2, fitting a cylinder based on the three-dimensional point cloud of the tunnel structure to obtain a central axis of tunnel point cloud; S3, constructing a plane based on the central axis of the tunnel point cloud and a given point, and intercepting a section of the tunnel point cloud based on the plane; S4, determining a center of the section of the tunnel point cloud; S5, extracting outline point clouds at a fixed angle range on both sides of the section based on the center of the section, and performing circle fitting on the outline point clouds respectively to obtain two outline circles; and S6, carrying out analysis of section convergence according to centers and radii of the outline circles on both sides of the section.

Abstract: A novel bi-directional vector modulator to be used as an active phase shifter is proposed. The advantages of the active phase shifter include: 1) Compact size—By active current combining technique, short transmission lines are used to perform signal combining rather than using area-consuming Wilkinson combiner or splitter; 2) High phase resolution and flexibility—phase interpolation can be performed by vector addition through m-path vector modulators; 3) High efficiency—no signal switch loss, only switched matching capacitor; 4) Simplified signal interconnection; 5) No passive combiner needed—eliminate large size and losses in the passive combiner); 6) Can have unequal combining and/or splitting by changing the gain of vector modulator, which is difficult to realize with passive combining and/or splitting network; and 7) Can combine different signals.

Abstract: A wideband tunable frequency single-subband converter is proposed. The wideband frequency tunable converter operates within a wideband and tunable frequency range, and has process, voltage, and temperature (PVT) tracking capability. In one embodiment, the wideband converter comprises a frequency tunable polyphase filter having a plurality of switchable polyphase resistors. The polyphase resistors are controlled by a frequency tuning control signal to achieve wideband frequency tunability. In a preferred embodiment, a triode mode transistor is used as a polyphase resistor, and a different resistance value of the polyphase filter is realized by turning on one or multiple of the different transistors in triode mode. In addition, a constant Gm(R) bias generator is used to provide the gate biases to the triode mode transistors to maintain a constant and stable resistance value across PVT and other variation.

Abstract: A bi-directional active combiner and splitter using bi-directional variable gain amplifiers (BD_VGAs) is proposed. Advantages of the proposed bi-directional active combiner and splitter includes the following 1) compact size—for each BD_VGA, cascode transistor pair is small and the same matching network is used by the cascode transistor pair for both directions; 2) high efficiency—no switching loss in signal path, only switched matching; 3) reduced passive trace loss and power consumption—simplified signal interconnection; 4) active current combining—eliminates large size in the passive combiner; 5) high input-output isolation—cascode and neutralization; 6) precise gain control and unequal combining or splitting—changing the gain of the BD_VGA; and 7) phase-invariant amplifier design.

Abstract: A novel bi-directional vector modulator to be used as an active phase shifter is proposed. The advantages of the active phase shifter include: 1) Compact size—By active current combining technique, short transmission lines are used to perform signal combining rather than using area-consuming Wilkinson combiner or splitter; 2) High phase resolution and flexibility—phase interpolation can be performed by vector addition through m-path vector modulators; 3) High efficiency—no signal switch loss, only switched matching capacitor; 4) Simplified signal interconnection; 5) No passive combiner needed—eliminate large size and losses in the passive combiner); 6) Can have unequal combining and/or splitting by changing the gain of vector modulator, which is difficult to realize with passive combining and/or splitting network; and 7) Can combine different signals.

Abstract: A bi-directional active combiner and splitter using bi-directional variable gain amplifiers (BD_VGAs) is proposed. Advantages of the proposed bi-directional active combiner and splitter includes the following 1) compact size—for each BD_VGA, cascode transistor pair is small and the same matching network is used by the cascode transistor pair for both directions; 2) high efficiency—no switching loss in signal path, only switched matching; 3) reduced passive trace loss and power consumption—simplified signal interconnection; 4) active current combining—eliminates large size in the passive combiner; 5) high input-output isolation—cascode and neutralization; 6) precise gain control and unequal combining or splitting—changing the gain of the BD_VGA; and 7) phase-invariant amplifier design.

Abstract: The present invention provides a method for fabricating a working electrode. The method comprises the following steps: providing a photoelectrode, which comprises a conductive substrate with a semiconductor material; providing a dye solution, which comprises a dye dissolved in a solvent; and applying a voltage for conducting an electrophoresis to adsorb said dye onto a surface of said semiconductor material. The method of present invention makes the dye adsorbed fast to a surface of a semiconductor material by electrophoresis, and therefore, significantly reduces the time for fabricating a dye-sensitized solar cell.

Abstract: A system for positioning based on magnetic field characteristics includes a system apparatus and a client device. The system apparatus includes a characteristic magnetic field generation device, a magnetic field characteristic database and a processing device. The characteristic magnetic field generation device is used for generating a plurality of characteristic magnetic fields in a predetermined space. The characteristic magnetic fields have at least two magnetic field characteristics. The magnetic field, characteristic database has a plurality of characteristic values and a plurality of positioning values. Each of the characteristic values corresponds to each of the magnetic field characteristics. The characteristic values correspond to the magnetic field characteristics. The client device includes a magnet detecting component and a processor. The magnet detecting component is used for detecting the magnetic field characteristics and for outputting a magnetic field signal.

Abstract: A method of cleaning a photolithographic mask or semiconductor wafer involves mixing a gas and water in a jetspray nozzle and discharging the gas and water jetspray stream from a nozzle onto the photolithographic mask or wafer. The water jetspray stream is made up of a cluster of micro water droplets entrained in the gas having a predetermined size sufficient to dislodge contaminant particles adhered to the surface of the mask. The step of mixing the gas and water includes radially injecting the gas from a first plurality of circumferentially spaced apart gas nozzles into a stream of the water and radially injecting the gas from a second plurality of circumferentially spaced apart gas nozzles into the stream of the water, wherein the second plurality of gas nozzles are spaced above or below the first plurality of gas nozzles and radially offset from the first plurality of gas nozzles.