摘要:
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, thickness of a dielectric layer, and thickness of an insulation tube can be changed. When any component needs to be replaced, each cover is rotated, with connection partitions moving to two slots of an insulation portion, to detach the filter.
摘要:
A design method generates a plurality of groups of experimental conditions, each of the groups of experimental conditions includes performance variables for an electronic product with nonlinear performance. The method simulates values to the groups of experimental conditions, computes an average value, and divides the groups of experimental conditions into a first part and a second part. The values in the first part is greater than the average value and the values in the second part is less than the average value. The method computes nonlinear boundary values of a refining mechanism based on the values, and determines a threshold value of the refiner. After refining the groups of experimental conditions, the method calculates the deviation of each value from the threshold value, and determines the groups of experimental conditions with the greatest deviations as optimal groups of experimental conditions.
摘要:
A circuit topology for multiple loads includes a driving terminal for transmitting a driving signal, a number of transmitting lines, and a number of loads operable to receive the driving signal from the driving terminal. The number of loads are connected to the driving terminal one by one via the number of transmitting lines. Two transmitting lines of the number of transmitting lines, which are nearest and farthest respectively from the driving terminal, are both greater than widths of the other transmitting lines.
摘要:
A signal transmission apparatus used in a printed circuit board (PCB). The apparatus includes a differential pair composed of two transmission lines arranged side by side in the PCB. The differential pair includes a filter section arranged therein to filter noise of transmission signals of the differential pair. The filter includes a number of section pairs connected in series. Each section pair includes two sections arranged in the two transmission lines symmetrically. Every two adjacent sections are different in line width. A distance between the two transmission lines, and the line width of each of the sections are predetermined according to desired frequency bandwidth, and desired frequency response of the differential pair.
摘要:
A signal transmission apparatus includes two circuit layers. First and second ground sheets are arranged in the two circuit layers respectively. A third ground sheet is arranged between the two circuit layers. A differential pair includes a transmission line arranged between the first and third ground sheets and a transmission line arranged between the second and third ground sheets. The first to third ground sheets have same electric potential. Projections of the first and second ground sheets on the third ground sheet superpose a border of the third ground sheet. The third ground sheet is formed by extending the border along a signal transmission direction. A vertical distance between the first and second transmission lines is twice as each of a vertical distance from the first ground sheet to the first transmission line and a vertical distance from the second ground sheet to the second transmission line
摘要:
A differential signal transmission device transmits N differential signal pairs from a differential signal generator to a number of receiving terminals. The N differential signal pairs include N positive signals and N negative signals. The N positive signals are clustered at a first positive clustering point. The first positive clustering point is connected to a second positive clustering point via a first matching resistor. The second positive clustering point is grounded via a first grounding resistor, and outputs a number of positive signals to the number of receiving terminals respectively. The N negative signals are clustered at a first negative clustering point. The first negative clustering point is connected to a second negative clustering point via a second matching resistor. The second negative signal clustering point is grounded via a second grounding resistor, and outputs a number of negative signals to the number of receiving terminals respectively.
摘要:
A printed circuit board includes first and second transmission lines connected to a first high speed differential signal control chip, third and fourth transmission lines connected to a second high speed differential signal control chip, and fifth and sixth transmission lines connected to a connector pad. To have the first high speed differential signal control chip communicate with the connector pad, the first transmission line is connected to the fifth transmission line through a first connection component, and the second transmission line is connected to the sixth transmission line through a second connection component. To have the second speed differential signal control chip communicate with the connector pad, the third transmission line is connected to the fifth transmission line through the first connection component, and the fourth transmission line is connected to the sixth transmission line through the second connection component.
摘要:
In a method of managing process factors that influence electrical properties of printed circuit boards (PCBs), n process factors are arranged in an order according to different influence to one kind of electrical property of the PCBs. The different influence is determined by first experiments designed using the Taguchi method. M process factors that have important influence to the electrical property are obtained from the n process factors according to the order to design second experiments. A computing formula for the electrical property is fitted using the m process factors according to simulated results of the second experiments, and a variation range of each of the m process factors is computed according to the computing formula.
摘要:
An electronic device includes a multi-frequency antenna. The multi-frequency antenna includes a ground portion, a support body, a radiation portion, and a strap. The ground portion defines a gap, and two grooves communicating with the gap and located at opposite ends of the gap. The radiation portion resists against a sidewall bounding the gap, and is connected to the strap. The radiation portion is accommodated in the gap and substantially coplanar with the ground portion. The radiation portion defines a slot. The support body is located in the gap and on the radiation portion, to support the strap.
摘要:
A FPCB includes a signal layer, a ground layer, and a dielectric layer lying between the signal layer and the ground layer. At least one high speed signal transmission line is formed on the signal layer. The ground layer has a copper-removed area corresponding to the transmission line. Two ground lines are symmetrically disposed at two opposite sides of the signal transmission line and substantially parallel to the signal transmission line, each ground line and the signal transmission line is spaced at a first predetermined distance. Each ground line and the signal transmission line are spaced at a first predetermined distance.