In this paper, we propose a fractional frequency synthesizer (FFS) based on an all digital phase-locked loop (ADPLL). A phase-frequency detector (PFD) is developed for reducing two independent comparisons and a dual-m...
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In this paper, we propose a fractional frequency synthesizer (FFS) based on an all digital phase-locked loop (ADPLL). A phase-frequency detector (PFD) is developed for reducing two independent comparisons and a dual-modulus frequency divider (FD) with divided by four or five is employed to perform variable fractions. Then a phase-frequency acquisition (PFA) is involved by the modified binary search algorithm (MBSA) with an initial half-step size to speed up for convergence. The frequency synthesizer is implemented with TSMC 0.35μm 1P4M CMOS technology. Experimental simulations show more encouraging results. The chip area is smaller to 1.3×1.3 mm2, locked time is less than 20 reference cycles, power consumption is only 15mW, and jitter is 90ps at 300MHz.
An electro-optical antenna measurement system is setup by replacing the traditional RF coaxial cable with an electro-optical system and optical fibers. It can reduce the disturbance of electromagnetic field around the...
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One of the key challenges in telepresence and teleaction systems is the fact that a global control loop is closed over a communication network. The transmission delay of haptic information is extremely critical. There...
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The rapid growth of traffic induced by Internet services makes the simple over-provisioning of resources not economical and hence imposes new requirements on the dimensioning methods. Therefore, the problem of network...
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For its unique merits, the reflective intensity-modulated fiber-optic sensing technique was widely applied in displacement detection and became research hotspot. However, the stability of light source, the disturbance...
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For its unique merits, the reflective intensity-modulated fiber-optic sensing technique was widely applied in displacement detection and became research hotspot. However, the stability of light source, the disturbance of environment and the reflectivity variation of the measured surface had effects on the merchandising process. The current work for us to do was to find out some technique scheme suitable for the product merchandising. Thus the fiber-optic sensing technique could be used more widely in national defence and economic construction. The working principle of reflective intensity-modulated fiber optic sensor was presented. And the latest research findings and the application of it in displacement detection were also given.
In this paper, we propose power and data wireless transfer techniques for a typical radio-frequency identification (RFID) system. The system consists of a reader unit and a transponder unit. The carrier of 13.56MHz is...
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In this paper, we propose power and data wireless transfer techniques for a typical radio-frequency identification (RFID) system. The system consists of a reader unit and a transponder unit. The carrier of 13.56MHz is used for inductive coupling between two units. The complementary class-E power amplifier in the reader unit is designed for power transmission and the 10% ASK (amplitude shift keying) modulation is appropriated for data transmission. The system has approved by using HSpice in TSMC 0.35 μm CMOS process. The power amplifier can improve up to 30% in power efficiency. With the coupling modulated RF signal, the power transfer can support up to 2.5V DC for the transponder unit and the data transfer can correctly demodulate the data. The transponder unit was also implemented to be a chip with the layout area of 1.13×1.12 mm2 and the low power of 2.958mW. The measurement for the fabricated chip shows that it can out-put 2.513V DC from the voltage regulator and demodulate the data rate of 100KHz.
Infrared (IR) and visible images are commonly used in the detection and tracking of a moving target. A novel contour extraction scheme for a moving vehicle is proposed in this paper. Firstly, a motion segmentation tec...
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This paper, we propose a new phase-locked loop (PLL) system with controllable the output phase independent from the output frequency and lock-up time. This PLL system has a dual control loop is described, the inner lo...
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Infrared (IR) and visible sensors are commonly used in the target tracking and recognition system. Image fusion for these two modal images can effectively improve the system's tracking and detection accuracy. The ...
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Infrared (IR) and visible sensors are commonly used in the target tracking and recognition system. Image fusion for these two modal images can effectively improve the system's tracking and detection accuracy. The model of dynamic contour is combined with image fusion and feature points in feature search are used to implement image registration accurately. Meanwhile a new feature-level image fusion is applied. control points of B-spline curves for the target's contour in two modal images are used to implement a real-time differential coupling. This coupling makes improvement on the differential coupling proposed by Curwen, where a rigid template is transformed into a real-time transformation template with image registration. Moreover, a new dynamic equation is derived for dynamic contour after this image fusion. In this fusion, the dynamic contour's convergent shape in visible image is restricted by the targets contour in IR image. This fusion improves dynamic contour's tracking accuracy effectively. A contrasting experiment on moving hand image sequence indicates average tracking error of dynamic contour has decreased by 60.25% in visible image with this image fusion.
A novel approach to an objects surface area measurement is proposed. It is suitable for area computation of an object with smooth and irregular edges. This approach consists of 4 steps. Firstly, a photoelectric image ...
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A novel approach to an objects surface area measurement is proposed. It is suitable for area computation of an object with smooth and irregular edges. This approach consists of 4 steps. Firstly, a photoelectric image collimation system is applied to obtain a target image of a detected object. Secondly, a dynamic contour converges to the target contour edge from an initial position via feature search and iteration algorithm. Thirdly, two formulas for the area and centroid computation of a closed B-spline curve are applied to compute the image target s area and centroid exactly. Finally, a novel centroid-self-calibration technology is applied. It measures the pixel's size equivalence with the computed centroid and two-frequency laser to measure the true object s surface area exactly. Experiments indicate that this approach's average error can decrease to ± 0.5%. Compared to conventional area measurement approaches, this approach is robust for area computation in a background image with noises or for a target with many internal complicated edges.
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