Abstract: A direct current compensation method for S-parameter rational functions reads S-parameters f(sk), which are generated at given frequency sk, from a storage unit. An S-parameter, which is generated at frequency sk=0 is supplemented into the S-parameters f(sk), upon the condition that there is no S-parameter which is generated at the frequency sk=0. An S-parameter ration function is generated according to the S-parameters f(sk). A DC level of the S-parameter rational function is compensated to generate a compensated S-parameter rational function.

Abstract: A signal transmission line check method to be executed by a computing device is described. A to-be-checked signal transmission line group in a displayed printed circuit board (PCB) layout is determined. Whether all signal transmission lines of the to-be-checked signal transmission line group are laid out in a same layer of the displayed PCB layout is checked according to an input serial number of a chipset and layer properties of the to-be-checked signal transmission lines. The signal transmission lines that do not satisfy design standards are determined when not all of the to-be-checked signal transmission lines are laid out in a same layer. A related computing device is also disclosed.

Abstract: A printed circuit board (PCB) includes a receiver component, a transmission line including a positive signal transmission line and a negative signal transmission line, a transmitter component, and a capacitance unit. The transmitter component transmits a different signal to the receiver component via the transmission line. The capacitance unit is spaced from the receiver component a predetermined distance S, therein, the predetermined distance S is calculated by a formula S=Vx (n*UI?(C1+C2)×Zo/2)/2, and V is a speed of the transmission line. C1 is an equivalent capacitance value of the receiver component, C2 is a capacitance value of the capacitance unit, Zo is a resistance value of the transmission line, UI is a half of one cycle of the differential signal, and n is a value less than or equal to 1.5 and greater than or equal to 0.5.

Abstract: In a method for checking a wiring diagram in a printed circuit board (PCB) design, a pair of differential signal lines in a PCB file is located according to a designation of a user. Components connected by the differential signal lines and vias which the differential signal lines pass through are obtained from the PCB file. A determination of whether obtained components and the obtained vias meet predetermined requirements is made by checking whether copper foils between each pair of the obtained vias or between pins of the obtained components in ground layers and power layers of the PCB file are hollowed.

Abstract: A signal transmission line check method to be executed by a computing device is described. A to-be-checked signal transmission line group in a displayed printed circuit board (PCB) layout is determined. Whether all signal transmission lines of the to-be-checked signal transmission line group are laid out in a same layer of the displayed PCB layout is checked according to an input serial number of a chipset and layer properties of the to-be-checked signal transmission lines. The signal transmission lines that do not satisfy design standards are determined when not all of the to-be-checked signal transmission lines are laid out in a same layer. A related computing device is also disclosed.

Abstract: A method for modulating multiple-instruments and multiple-sensors using an electronic device. The electronic device controls an instrument to measure the working parameters of an object, and controls a sensor to detect the working temperature of the object. By comparing the working parameters against a predefined range, and comparing the working temperature against a predefined temperature value, the electronic device determines whether the instrument and the sensor need to be modulated. If any of the working parameters is not within the predefined range or if the working temperature is greater than the predefined temperature value, the electronic device controls the instrument and the sensor to be modulated by using a modulation transfer function and a predetermined direction.

Abstract: A method for shortening a via stub includes: designing a first via hole to connect signal lines of a top layer and a bottom layer of a printed circuit board; and designing a second via hole to connect signal lines of the bottom layer and one of a number of middle layers of the printed circuit board. The printed circuit board include n layers, n is an even number, and the number of the one of the number of middle layers counting top down or bottom up is less than or equal to n/2. A related printed circuit board is also provided.

Abstract: In a method for checking wiring diagrams, one element is selected from a first printed circuit board (PCB) file. An element corresponding to the selected element in a second PCB file is searched according to information of the selected element, then the information is recorded into a different element list of the first PCB file, when the second PCB file does not have a corresponding element. The information is recorded into a same element list, when the second PCB file has a corresponding element and the corresponding element has the same information with the element in the first PCB file. The second PCB file and the same element list are compared to locate elements which are included in the second PCB file but not included in the same element list, and the information of the located elements is recorded into a different element list of the second PCB file.

Abstract: A system and method for measuring performance of an electronic product using a measurement control device that connects to a measuring machine and a display device. A component of the electronic product is determined according to a coordinate array, and a physical factor of the component to measured is determined according to performance specifications of the electronic product. A sensor corresponding to the physical factor of the component is selected from sensors of the measuring machine, and a physical factor of each the component is measured by the selected sensor. The system indicates whether the electronic product is workable or unworkable by comparing the physical factors of the components with the performance specifications of the components, and generates a measurement report for evaluating the performance of the electronic product according to the indication results.

Abstract: An exemplary guideway mechanism includes two branches, a plurality of branches each including two parallel rails, a plurality of groups of connecting blocks including four connecting blocks arranged at four corners of an imaginary square, and a plurality of supporting brackets each connecting one corresponding group of connecting blocks. Adjacent ends of the rails of each branch respectively connect two adjacent connecting blocks. Each of two ends of each rail connects one corresponding connecting block. Two adjacent rails respectively located in two adjacent branches are perpendicular to each other and connected together by a respective connecting block of one corresponding group of connecting blocks. The other two rails respectively located in the two adjacent branches connect another two respective connecting blocks of the one corresponding group of connecting blocks. The whole guideway mechanism is in the form of a grid.

Abstract: An exemplary guideway mechanism includes four branches each including two parallel rails, four groups of connecting blocks each including four connecting blocks arranged at four corners of an imaginary square, and four supporting brackets each connecting one corresponding group of connecting blocks. Adjacent ends of the rails of each branch respectively connect two adjacent connecting blocks. Each of two ends of each rail connects one corresponding connecting block. Two adjacent rails respectively located in two adjacent branches are perpendicular to each other and connected together by a respective connecting block of one corresponding group of connecting blocks. The other two rails respectively located in the two adjacent branches connect another two respective connecting blocks of the one corresponding group of connecting blocks. The whole guideway mechanism is frame-shaped.

Abstract: Parameters of a radio frequency filter can be changed by changing structure of each component of the filter. Material of each component, diameters of each of magnetic cylinders, density of each of conductive coils, and thickness of each of dielectric layers can be changed. When any component needs to be replaced, the filter can be detached as needed.

Abstract: In a method for checking the length of a signal trace between a coupling capacitor and a via in a printed circuit board (PCB) design using a computing device, a PCB file is obtained from a storage device to simulate a PCB design. The signal trace between the coupling capacitor and the via is filtered on the PCB design, and a real length of the signal trace between the coupling capacitor and the via is calculated. If the real length is greater than a specified length, the method locates a position of the via on the PCB design and generates a design report indicating that the signal trace between the coupling capacitor and the via is unqualified. The method further displays information of the signal trace on a display device of the computing device.

Abstract: An exemplary guideway mechanism includes two branches, a group of connecting blocks, and a supporting bracket. The group of connecting blocks includes four connecting blocks arranged at four corners of an imaginary square and connecting the supporting bracket. Each branch includes two parallel rails. Adjacent ends of the rails of each branch respectively connect two adjacent connecting blocks.

Abstract: A power supply system supplies power includes a single power supply unit to supply power for a number of motherboards. A number of power management chips are provided corresponding to the motherboards, to monitor a real-time power consumption of each motherboard. A microcontroller is connected to each of the motherboards through a data line, to control a total power consumption of the motherboards to control power consumption to remain within a nominal power of the power supply unit.

Abstract: A pad includes a first mating section and a second mating section. The first mating section includes a first horizontal plane and a first inclined plane. The second mating section includes a second horizontal plane and a second inclined plane. The first mating section is a copper foil capable of being connected to a wire. The second mating section is made of insulating material. The first inclined plane and the second inclined plane are bonded together.

Abstract: An exemplary actuating mechanism includes a driving shaft and a driven shaft. The driving shaft includes a connecting end. Engaging blocks are formed on the connecting end with a clearance defined between each two neighboring engaging blocks. The driven shaft includes a pivot end. Protruding blocks are formed on the pivot end with a gap defined between each two neighboring protruding blocks. The driving shaft is connected with the driven shaft via the engaging blocks of the connecting end respectively engaged in the gaps and the protruding blocks of the pivot end respectively engaged in the clearances.

Abstract: A simulation system for producing equivalent circuits reads data corresponding to a tabular W element format in a storage device, and adds data of the tabular W element format file using interpolation algorithm. A frequency-dependent transmission matrix is transformed into an N-port network matrix describing electrical properties of a multi-input and multi-output network. An N-port network matrix is transformed into a S-parameter matrix. A range of frequency of a s-parameter is determined and numbers of pole-residue, times for recursion and durable maximum system errors in the equivalent circuit is also determined. A vector fitting algorithm is performed and a rational function matrix composed with s-parameters is produced, to produce a general SPICE equivalent circuit based on the generated rational function matrix.

Abstract: A serial advanced technology attachment (SATA) DIMM includes a board body. A control chip is arranged on the board body. An extending board extends from an end of the board body. A first edge connector is set on the extending board. A second edge connector is set on a bottom side of the board body. The first edge connector includes a number of signal pins connected to the control chip, and a number of ground pins.

Abstract: A printed circuit board includes a signal layer and a reference layer. The signal layer is covered with copper foil. A circuit topology for multiple loads is set on the signal layer. The circuit topology includes a driving terminal, a first signal receiving terminal, and a second signal receiving terminal. The driving terminal is connected to a node through a first transmission line. The node is connected to the first and second signal receiving terminals respectively through a second and a third transmission lines. A difference between lengths of the second and third transmission lines is greater than a product of a transmission speed and a rise time of signals from the driving terminal. The reference layer is covered with copper foil, and arranged under the signal layer. A region without copper foil is formed on the reference layer, under the second transmission line.