Capacitors are one of the true “building-block” components of circuit design, along with resistors and inductors. They come in many shapes and sizes, in fixed and variable capacitance values, with tiny capacitors based on ceramic dielectric materials among the most popular for printed-circuit-board (PCB) applications.
Both single-layer and multilayer ceramic capacitors are commonly used in RF/microwave circuits, attractive for their small size for use in surface-mount electronic designs. The two types of ceramic capacitors are often available from the same manufacturer, which begs the question: Why use one type or the other? And what are the differences between them? Let’s find out.
All capacitors are charge-storing components based on at least two electrical conductors or plates separated by some form of dielectric insulating material. For any capacitor, the amount of charge per amount of applied voltage is a function of the area of the plates, the characteristics of the dielectric material, and the distance between the plates. The capacitance for a capacitor formed with two conducting plates is simply