Electrical length

For digital circuits, the electrical length of the line can be defined relative to the signal rise time. A common rule of thumb for simple lines with no branches is that interconnections must be treated as transmission lines when the round-trip transit time of the signal, 2t pdZ, exceeds the signal rise time, tr (37). This rule defines a critical line length (Zc) given by... 

A physical sensor measures physical quantities including electricity, length, temperature and weight. 

Here, the following dimensionless parameters appear Peclet number Pe = UsofEol/DA and the aspect ratio k = where I is the electrical length scale obtained by balancing diffusion and electromigration flux, I = Da/Uytp. 

The effect of fringing fields at the end of the coaxial sample line can usually be made small but not negligible. Two ways of accounting for it are to use Equation 7 with an appropriate expression for yj or to use an effective electrical length d that is larger than the physical length d and determined by calibration with samples of known <. The solutions for including these effects are discussed in reference 11. 

The first and most direct is shown in Fig. D.12. Here all elements are fed via a harness as shown. The impedance Za of a typical element is detennined by insertion of an appropriate reflectometer or impedance measuring device. Neither of these devices should have any attenuation, and their electrical length must be incorporated in the feed cable. From the complex reflection coefficient F at the element terminal we find... 

The field-induced force can be important only when the separation between the disclination lines exceeds the electric length scale, which is on the order of... 

A coaxial cable expands as the temperature of the cable increases, causing the electrical length of the line to increase as well. This factor results in phase changes that are a function of operating temperature. The phase relationship can be described by... 

The electrical length of a radiating element is the most basic parameter of an antenna... 

With critical arrays (antennas requiring operation within tight limits specified in the station license), all sample lines must be of equal electrical length and installed in such a manner that corresponding lengths of all lines are exposed to equal environmental conditions. 

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