Search results
Results From The WOW.Com Content Network
For example, the point P1 in the example representing a reflection coefficient of has a normalised impedance of = +. To graphically change this to the equivalent normalised admittance point, say Q1, a line is drawn with a ruler from P1 through the Smith chart centre to Q1, an equal radius in the opposite direction.
The resonant frequency is defined as the frequency at which the impedance of the circuit is at a minimum. Equivalently, it can be defined as the frequency at which the impedance is purely real (that is, purely resistive). This occurs because the impedances of the inductor and capacitor at resonant are equal but of opposite sign and cancel out.
In electrical engineering, impedance is the opposition to alternating current presented by the combined effect of resistance and reactance in a circuit. [1]Quantitatively, the impedance of a two-terminal circuit element is the ratio of the complex representation of the sinusoidal voltage between its terminals, to the complex representation of the current flowing through it. [2]
After the mesh equation is formed, a dependent source equation is needed. This equation is generally called a constraint equation. This is an equation that relates the dependent source’s variable to the voltage or current that the source depends on in the circuit. The following is a simple example of a dependent source. [2]
For example, when tuning a radio to a particular station, the LC circuits are set at resonance for that particular carrier frequency. A series resonant circuit provides voltage magnification. A parallel resonant circuit provides current magnification. A parallel resonant circuit can be used as load impedance in output circuits of RF amplifiers.
Due to the reactive nature of a speaker's impedance over the audio band frequencies, giving a speaker a single value for impedance rating is in principle impossible, as one may surmise from the impedance–vs.–frequency curve shown. The nominal impedance of a loudspeaker is a convenient, single number reference that loosely describes the ...
For all ports the voltages may be defined in terms of the Z-parameter matrix and the currents by the following matrix equation: = where Z is an N × N matrix the elements of which can be indexed using conventional matrix notation. In general the elements of the Z-parameter matrix are complex numbers and
The simplest switched-capacitor (SC) circuit is made of one capacitor and two switches S 1 and S 2 which alternatively connect the capacitor to either in or out at a switching frequency of . Recall that Ohm's law can express the relationship between voltage, current, and resistance as: =.