|
Via Fence
A via fence, also called a picket fence, is a structure used in planar electronic circuit technologies to improve isolation between components which would otherwise be coupled by electromagnetic fields. It consists of a row of via holes which, if spaced close enough together, form a barrier to electromagnetic wave propagation of slab modes in the substrate. Additionally if radiation in the air above the board is also to be suppressed, then a strip pad with via fence allows a shielding can to be electrically attached to the top side, but electrically behave as if it continued through the PCB. Modern electronics have components and sub-units at high densities to achieve small size. Typically, many functions are integrated on to the same board or die. If these are not properly shielded from each other, many problems can result including poor frequency response, noise performance, and distortion. Via fences are used to shield microstrip and stripline transmission lines, guard e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Via Fence Line
Via or VIA may refer to the following: Science and technology * MOS Technology 6522, Versatile Interface Adapter * ''Via'' (moth), a genus of moths in the family Noctuidae * Via (electronics), a through-connection * VIA Technologies, a Taiwanese manufacturer of electronics * Virtual Interface Adapter, a network protocol * Virtual Interface Architecture, a networking standard used in high-performance computing Education * VIA Vancouver Institute for the Americas, an organization dedicated to education for sustainable development, since 1998 operating in Canada * VIA University College, a university college (Danish: professionshøjskole), since 2008 established in Denmark * VIA, Association of Information Sciences (Dutch: VIA Vereniging Informatiewetenschappen Amsterdam), at the University of Amsterdam, in the Netherlands Transportation * The name for a Roman road, e.g., ''Via Appia'' * VIA was the ICAO airline designator for Venezuelan airline Viasa (1960-1977) * VIA Me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Signal Reflection
In telecommunications, signal reflection occurs when a signal is transmitted along a transmission medium, such as a copper cable or an optical fiber. Some of the signal power may be reflected back to its origin rather than being carried all the way along the cable to the far end. This happens because imperfections in the cable cause impedance mismatches and non-linear changes in the cable characteristics. These abrupt changes in characteristics cause some of the transmitted signal to be reflected. In radio frequency (RF) practice this is often measured in a dimensionless ratio known as voltage standing wave ratio (VSWR) with a VSWR bridge. The ratio of energy bounced back depends on the impedance mismatch. Mathematically, it is defined using the reflection coefficient. Because the principles are the same, this concept is perhaps easiest to understand when considering an optical fiber. Imperfections in the glass create mirrors that reflect the light back along the fiber. Imp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Printed Circuit
A printed circuit board (PCB; also printed wiring board or PWB) is a medium used in electrical and electronic engineering to connect electronic components to one another in a controlled manner. It takes the form of a laminated sandwich structure of conductive and insulating layers: each of the conductive layers is designed with an artwork pattern of traces, planes and other features (similar to wires on a flat surface) etched from one or more sheet layers of copper laminated onto and/or between sheet layers of a non-conductive substrate. Electrical components may be fixed to conductive pads on the outer layers in the shape designed to accept the component's terminals, generally by means of soldering, to both electrically connect and mechanically fasten them to it. Another manufacturing process adds vias: plated-through holes that allow interconnections between layers. Printed circuit boards are used in nearly all electronic products. Alternatives to PCBs include wire wrap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Frequency
Radio frequency (RF) is the oscillation rate of an alternating electric current or voltage or of a magnetic, electric or electromagnetic field or mechanical system in the frequency range from around to around . This is roughly between the upper limit of audio frequencies and the lower limit of infrared frequencies; these are the frequencies at which energy from an oscillating current can radiate off a conductor into space as radio waves. Different sources specify different upper and lower bounds for the frequency range. Electric current Electric currents that oscillate at radio frequencies (RF currents) have special properties not shared by direct current or lower audio frequency alternating current, such as the 50 or 60 Hz current used in electrical power distribution. * Energy from RF currents in conductors can radiate into space as electromagnetic waves ( radio waves). This is the basis of radio technology. * RF current does not penetrate deeply into ele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Via Fence Edge
Via or VIA may refer to the following: Science and technology * MOS Technology 6522, Versatile Interface Adapter * ''Via'' (moth), a genus of moths in the family Noctuidae * Via (electronics), a through-connection * VIA Technologies, a Taiwanese manufacturer of electronics * Virtual Interface Adapter, a network protocol * Virtual Interface Architecture, a networking standard used in high-performance computing Education * VIA Vancouver Institute for the Americas, an organization dedicated to education for sustainable development, since 1998 operating in Canada * VIA University College, a university college (Danish: professionshøjskole), since 2008 established in Denmark * VIA, Association of Information Sciences (Dutch: VIA Vereniging Informatiewetenschappen Amsterdam), at the University of Amsterdam, in the Netherlands Transportation * The name for a Roman road, e.g., ''Via Appia'' * VIA was the ICAO airline designator for Venezuelan airline Viasa (1960-1977) * VIA Me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Resistance
The electrical resistance of an object is a measure of its opposition to the flow of electric current. Its reciprocal quantity is , measuring the ease with which an electric current passes. Electrical resistance shares some conceptual parallels with mechanical friction. The SI unit of electrical resistance is the ohm (), while electrical conductance is measured in siemens (S) (formerly called the 'mho' and then represented by ). The resistance of an object depends in large part on the material it is made of. Objects made of electrical insulators like rubber tend to have very high resistance and low conductance, while objects made of electrical conductors like metals tend to have very low resistance and high conductance. This relationship is quantified by resistivity or conductivity. The nature of a material is not the only factor in resistance and conductance, however; it also depends on the size and shape of an object because these properties are extensive rather than in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capacitance
Capacitance is the capability of a material object or device to store electric charge. It is measured by the change in charge in response to a difference in electric potential, expressed as the ratio of those quantities. Commonly recognized are two closely related notions of capacitance: ''self capacitance'' and ''mutual capacitance''. An object that can be electrically charged exhibits self capacitance, for which the electric potential is measured between the object and ground. Mutual capacitance is measured between two components, and is particularly important in the operations of the capacitor, a device designed for this purpose as an elementary linear electronic component. Capacitance is a function only of the geometry of the design of the capacitor, e.g., the opposing surface area of the plates and the distance between them, and the permittivity of the dielectric material between the plates. For many dielectric materials, the permittivity and thus the capacitance, is in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inductance
Inductance is the tendency of an electrical conductor to oppose a change in the electric current flowing through it. The flow of electric current creates a magnetic field around the conductor. The field strength depends on the magnitude of the current, and follows any changes in current. From Faraday's law of induction, any change in magnetic field through a circuit induces an electromotive force (EMF) (voltage) in the conductors, a process known as electromagnetic induction. This induced voltage created by the changing current has the effect of opposing the change in current. This is stated by Lenz's law, and the voltage is called '' back EMF''. Inductance is defined as the ratio of the induced voltage to the rate of change of current causing it. It is a proportionality factor that depends on the geometry of circuit conductors and the magnetic permeability of nearby materials. An electronic component designed to add inductance to a circuit is called an inductor. It typ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Via Hole Equivalent Circuit
Via or VIA may refer to the following: Science and technology * MOS Technology 6522, Versatile Interface Adapter * ''Via'' (moth), a genus of moths in the family Noctuidae * Via (electronics), a through-connection * VIA Technologies, a Taiwanese manufacturer of electronics * Virtual Interface Adapter, a network protocol * Virtual Interface Architecture, a networking standard used in high-performance computing Education * VIA Vancouver Institute for the Americas, an organization dedicated to education for sustainable development, since 1998 operating in Canada * VIA University College, a university college (Danish: professionshøjskole), since 2008 established in Denmark * VIA, Association of Information Sciences (Dutch: VIA Vereniging Informatiewetenschappen Amsterdam), at the University of Amsterdam, in the Netherlands Transportation * The name for a Roman road, e.g., ''Via Appia'' * VIA was the ICAO airline designator for Venezuelan airline Viasa (1960-1977) * VIA Me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Via Fence Top Casting
Via or VIA may refer to the following: Science and technology * MOS Technology 6522, Versatile Interface Adapter * ''Via'' (moth), a genus of moths in the family Noctuidae * Via (electronics), a through-connection * VIA Technologies, a Taiwanese manufacturer of electronics * Virtual Interface Adapter, a network protocol * Virtual Interface Architecture, a networking standard used in high-performance computing Education * VIA Vancouver Institute for the Americas, an organization dedicated to education for sustainable development, since 1998 operating in Canada * VIA University College, a university college (Danish: professionshøjskole), since 2008 established in Denmark * VIA, Association of Information Sciences (Dutch: VIA Vereniging Informatiewetenschappen Amsterdam), at the University of Amsterdam, in the Netherlands Transportation * The name for a Roman road, e.g., ''Via Appia'' * VIA was the ICAO airline designator for Venezuelan airline Viasa (1960-1977) * VIA Me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ground Plane
In electrical engineering, a ground plane is an electrically conductive surface, usually connected to electrical ground. The term has two different meanings in separate areas of electrical engineering. *In antenna theory, a ground plane is a conducting surface large in comparison to the wavelength, such as the Earth, which is connected to the transmitter's ground wire and serves as a reflecting surface for radio waves. *In printed circuit boards, a ground plane is a large area of copper foil on the board which is connected to the power supply ground terminal and serves as a return path for current from different components on the board. Radio antenna theory In telecommunication, a ''ground plane'' is a flat or nearly flat horizontal conducting surface that serves as part of an antenna, to reflect the radio waves from the other antenna elements. The plane does not necessarily have to be connected to ground to be used as a reflecting surface for radio waves. Ground plane shap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Contact Pad
Contact pads or bond pads are designated surface areas of a printed circuit board (PCB) or die of an integrated circuit. Possibilities to contact to pads include soldering, wirebonding, flip chip Flip chip, also known as controlled collapse chip connection or its abbreviation, C4, is a method for interconnecting dies such as semiconductor devices, IC chips, integrated passive devices and microelectromechanical systems (MEMS), to extern ... mounting, or probe needles. Further reading *Kraig Mitzner, ''Complete PCB Design Using OrCAD Capture and PCB Editor'', Newnes, 2009 . *Jing Li, ''Evaluation and Improvement of the Robustness of a PCB Pad in a Lead-free Environment'', ProQuest, 2007 . *Deborah Lea, Fredirikus Jonck, Christopher Hunt, ''Solderability Measurements of PCB Pad Finishes and Geometries'', National Physical Laboratory, 2001 . Electronic engineering Printed circuit board manufacturing {{Electronics-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
