Abstract:
In an electronic device and a method of correcting time-domain reflectometers, two channels of a time-domain reflectometer are connected to a corrector using cables, and the two channels are enabled to transmit pulses. Parameters Step Deskew and Channel Deskew of the two channels are zeroed. Resistance values of the two channels are measured simultaneously, and the value of the parameter Step Deskew of one of the two channels is adjusted according to the Resistance values of the two channels. Times of achieving the same resistance value of the two channels are measured after the cables and the connector have been disconnected, and the value of the parameter Channel Deskew of one of the two channels is adjusted according to the times of achieving the same resistance value. The adjusted values of the parameters Step Deskew and Channel Deskew are displayed through a display unit.
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:
A system and method for inspecting layout of a printed circuit board (PCB) provides a graphical user interface (GUI). The GUI displays a layout of the PCB. High side pins of a pulse width modulation (PWM) controller and a component connected to a high side pin are found. If the component is a metallic oxide semiconductor field effect transistor (MOSFET), the system calculate absolute a linear distance and a trace distance between a source pin of the MOSFET and a capacitor pin of a coupling capacitor connected to the source pin. If the linear distance, the trace distance and a capacitance of the coupling capacitor accord with a layout standard, the layout of the PCB is determined to be up to standard.
Abstract:
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.
Abstract:
A flexible printed circuit board (FPCB) includes a differential pair arranged in a signal layer and a ground sheet arranged in a ground layer. The differential pair includes a number of section pairs, each of which includes two sections arranged in two transmission lines of the differential pair respectively. The ground sheet is opposite to a space between the two transmission lines of the differential pair. The differential pair is equivalent to a filter which includes several capacitors and several inductors. Each of the plurality of section pairs can achieve a desired characteristic impedance by adjusting a first distance between each section and the ground sheet, and a second distance between the two sections of each of the plurality of section pairs.
Abstract:
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
Abstract:
A method for testing a characteristic impedance of an electronic component includes sending a positioning command to a control computer through a switch, so as to drive a probe holder of a mechanical arm to position probes of a time domain reflectometer (TDR) on a position of the electronic component. The method further receives measured data collected by the TDR, and compares the measured data with preset standard values to determine if the measured data is acceptable.
Abstract:
A high-frequency module includes an antenna, an impedance matching circuit, and a transmission wire. The transmission wire is connected between the antenna and the impedance matching circuit. The transmission wire includes a dielectric layer, a signal layer, and two ground layers. The signal layer and the ground layers are located on the dielectric layer. The ground layers are located at opposite sides of the signal layer respectively. A space is formed between a signal and each ground layer.
Abstract:
A printed circuit board coupling includes a first layout layer, a second layout layer, a pair of connecting portions, a first component and a second component. The first layout layer has a pair of first conducting portions which is disposed thereon to couple with a control chip. The second layout layer has a pair of second conducting portions, third conducting portions, and fourth conducting portions all of which are sequentially disposed thereon. The connecting portions are coupled with the first conducting portions and the third conducting portions. In a first coupling mode, an electronic device is coupled with the second conducting portions, and first and second components are coupled with the third and fourth conducting portions. In a second coupling mode, the electronic device is coupled with the fourth conducting portions, and the first and the second components are coupled with the second and third conducting portions.
Abstract:
An exemplary FPCB includes two or more dielectric layers. Each dielectric layer is located between a signal layer and a ground layer. A differential pair including two transmission lines is arranged in each signal layer. Each ground layer includes one or more voids defined therein. Each void is opposite and adjacent to a differential pair.