摘要:
A performance evaluation system for a multiple-input multiple-output (MIMO) antenna system receives simulation parameters from an input device, and simulates a MIMO antenna system accordingly. A method, also provided, further evaluates performance of the simulated MIMO antenna system when a series of radio frequency (RF) signals are transmitted through the MIMO antenna system, and displays a performance analysis result of the MIMO antenna system on a display device for evaluation of the performance of the simulated MIMO antenna system.
摘要:
A printed circuit board includes a first signal layer, a second signal layer, and a dielectric layer sandwiched between the first signal layer and the second signal layer. The first signal layer includes two pads. The second signal layer includes two conducting pieces connected to two signal traces. The shape and material of the pads are the same as the shape and material of the conducting pieces. The projections of the pads on the second signal layer are overlapping with the conducting pieces.
摘要:
An enclosure includes a plate. The plate defines a number of through holes. A hollow shield extends from the edges bounding each through hole. A top side of the shield opposite to the plate is smaller than a bottom side of the shield which is connected to the edges of the through hole. The enclosure can better shield electromagnetic interference (EMI) from the electronic device.
摘要:
An enclosure of an electronic device includes a plate. The plate defines a number of through holes with a number of shields. Each shield includes a tab apart from the plate. At least two spaced connection pieces connect the tab to a corresponding through hole in such a way that the tab is substantially aligned with and spaced from the corresponding through hole.
摘要:
An enclosure of an electronic device includes a plate. The plate defines a number of through holes. A number of shields extend from the plate corresponding to the through holes. Each shield extends outwards from the outer surface of the plate, surrounding and partly covering a corresponding through hole. The enclosure with the shields can shield the electronic device from EMI.
摘要:
An enclosure includes a plate. The plate defines a number of through holes. A hollow shield extends from the edges bounding each through hole. A top side of the shield opposite to the plate is smaller than a bottom side of the shield which is connected to the edges of the through hole. The enclosure can better shield electromagnetic interference (EMI) from the electronic device.
摘要:
A printed circuit board includes a number of signal layers, a number of ground layers, a first transmission line, a second transmission line, a first via, and a second via. The first transmission is located on one of the number of signal layers. The second transmission line is located on another of the number of signal layers. The first and second vias pass through the printed circuit board. The first via is electrically coupled to the first and second transmission lines, and is isolated from the number of ground layers. The second via is electrically coupled to one or more of the number of ground layers, and is isolated from the other of the number of ground layers to increase an inductance, thus compensating capacitive nature of an open stub and improving signal integrity.
摘要:
An enclosure includes a plate. The plate defines a number of through holes. A first shield extends from an edge bounding each through hole. A second shield extends from the edge bounding each through hole, opposite to the first shields. Each through hole is partially covered by a corresponding first shield and a corresponding second shield. The enclosure with the shields can shield the electronic device from electromagnetic interference.
摘要:
A compensation method compensates for a length offset between a first transmission line and a second transmission line of a differential signal transmission. The compensation method includes calculating a transmission speed of a first signal in the first transmission line, measuring lengths of the first and second transmission lines, calculating a transmission time of the first signal in the first transmission line, and calculating a relationship between permittivity values of the first and second transmission lines. The compensation method further changes the permittivity values of the first and second transmission lines according to the relationship.
摘要:
A signal transmission apparatus includes two circuit layers. First and second ground sheets each has a rectangular area 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 two rectangular areas on a surface where the third ground sheet in only have one common border with the third ground sheet. The third ground sheet is formed by extending the common border along a signal transmission direction. The differential pair includes a number of section pairs each composed of two sections arranged in the two transmission lines symmetrically. Every two adjacent section pairs are equivalent to a capacitor and an inductor.