Examination of a capacitor’s S21 data will define these losses over the frequency range of interest. An insertion loss of several tenths of a dB is generally an acceptable criterion for virtually all applications. The 10 nF capacitor used in the above example is an X7R type, which provides an excellent solution for this requirement.
Another fundamental consideration for all capacitor applications is the insertion loss over the desired frequency band. It is especially important to carefully examine the magni-tude of S21 of a given capacitor for the presence of one or more parallel resonances falling within the desired pass-band.
Creating and Destroying Electric Energy...................................5-28 A capacitor is a device which stores electric charge. Capacitors vary in shape and size, but the basic configuration is two conductors carrying equal but opposite charges (Figure 5.1.1). Capacitors have many important applications in electronics.
The SI unit of capacitance is the farad ( F): 6 F ). Figure 5.1.3(a) shows the symbol which is used to represent capacitors in circuits. For a polarized fixed capacitor which has a definite polarity, Figure 5.1.3(b) is sometimes used. Figure 5.1.3 Capacitor symbols. Let’s see how capacitance can be computed in systems with simple geometry.
In both digital and analog electronic circuits a capacitor is a fundamental element. It enables the filtering of signals and it provides a fundamental memory element. The capacitor is an element that stores energy in an electric field. The circuit symbol and associated electrical variables for the capacitor is shown on Figure 1. Figure 1.
Figure 5.1.1 Basic configuration of a capacitor. In the uncharged state, the charge on either one of the conductors in the capacitor is zero. During the charging process, a charge Q is moved from one conductor to the other one, giving one conductor a charge + Q , and the other one a charge − Q .