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Twin lead cable is a two-conductor flat cable used as a balanced transmission line to carry radio frequency (RF) signals. It is constructed of two, stranded copper wires, or solid copper-clad steel wires. The wires are held a fixed distance apart by a plastic ribbon that is a good insulator at radio frequencies (usually polyethylene).
The phase velocity at which electrical signals travel along a transmission line or other cable depends on the construction of the line. Therefore, the wavelength corresponding to a given frequency varies in different types of lines, thus at a given frequency different conductors of the same physical length can have different electrical lengths.
A pair of parallel conductors with current Î 1 and Î 2 flowing on each conductor, which can be decomposed into CM and DM current respectively. Fig. 1. CM and DM Current Illustration on Pair Conductors. As shown in the figure above, the relations between Î 1, Î 2 and modal current are given: Î 1 = Î C + Î D Î 2 = Î C - Î D
Types of transmission line include parallel line (ladder line, twisted pair), coaxial cable, and planar transmission lines such as stripline and microstrip. [5] [6] The higher the frequency of electromagnetic waves moving through a given cable or medium, the shorter the wavelength of the waves. Transmission lines become necessary when the ...
The separation between the Lecher bars does not affect the position of the standing waves on the line, but it does determine the characteristic impedance, which can be important for matching the line to the source of the radio frequency energy for efficient power transfer. For two parallel cylindrical conductors of diameter d and spacing D,
Transposition is the periodic swapping of positions of the conductors of a transmission line, in order to reduce crosstalk and otherwise improve transmission. In telecommunications this applies to balanced pairs whilst in power transmission lines three conductors are periodically transposed.
The skin effect and proximity effect cause conductors to exhibit higher resistance to alternating current (AC) than to direct current (DC). Due to the dual inverse nature of the electromagnetic field, the skin effect dominates at frequencies less than about 2 MHz; at higher frequencies, the proximity effect becomes the dominant force, and Litz wire induces more DC losses than solid wire or ...
A parallel channel may have additional conductors for other signals, such as a clock signal to pace the flow of data, a signal to control the direction of data flow, and handshaking signals. Parallel communication is and always has been widely used within integrated circuits, in peripheral buses, and in memory devices such as RAM. Computer ...