The electromagnetic (EM) spectrum may be wide, but it’s not unlimited, and engineers depend on high-frequency filters to help keep EM signals in place. Filters gain in importance as the applications within RF, microwave (MW), and even millimeter-wave (mmWave) frequencies continue to expand, protecting signals of interest from noise and preventing nearby signals from causing unwanted interference. High-frequency filters are available in many technologies and package styles, and this special report facilitates the task of finding a filter that enables many EM signals to coexist.
RF/MW filters are frequency-control components that help squeeze the greatest number of applications into the least amount of spectrum possible. They can be fixed or tunable, active or passive. They’re simple in nature, designed to transfer some signals and stop others, such as for a radio channel. Such filters can be implemented on a printed circuit board (PCB) with essential lumped elements of a resistor (R), inductor (L), and capacitor (C), and they shrink in size relative to the wavelength of the frequencies of interest.