What Is Impedance (Z)?

The amount of resistance that a conductor component, circuit, or system offers to either direct or alternating current is measured using a concept called impedance (Z). In the case of alternating current, impedance is never equal to zero; its value may be determined by calculating the voltage across and the current flowing through a component, circuit, or system. Impedance is often represented in terms of ohms () in relation to electrical equipment. Since its value is never 0 or null in the case of alternating current, impedance is considered to have no effect while the voltage and current levels are held constant. The true aspect of impedance is represented by resistance. Impedance has a component known as reactance, which is fictional. Impedance is a two-dimensional quantity containing resistance (real component vector). It is a common misconception in the field of electrical engineering that impedance and resistance are interchangeable terms for the same thing. That is not an accurate statement. Impedance is a quantity that exists in two dimensions and is composed of resistance (the actual component vector) and reactance (imaginary component vector). The ratio of voltage to current in the frequency domain is another name for the concept of impedance. The amount of energy required to fight the flow of current via a circuit is the value that constitutes a circuit's resistance. Ohms are used as the unit of measurement, and the value can either be positive or negative. The amount of adjustment that is required of an antenna for it to match a specific voltage (or current) and be able to radiate energy effectively at a given frequency is referred to as the reactance of the antenna. At that frequency, it is measured in ohms per wavelength, and its value, which can be positive or negative, can also take either of those two possible directions.