High Pass Filter

What is a High Pass Filter?
High-pass filter, also known as low-cut filter, low-stop filter. A filter that allows frequencies above a certain cutoff frequency to pass, while greatly attenuating lower frequencies. It removes unnecessary low-frequency components in the signal or removes low-frequency interference.
Basic concept of high pass filter
A high-pass filter is a combination of components such as capacitors, inductors, and resistors that allow signal components above a certain frequency to pass through and greatly suppress signal components below the frequency. Its characteristics can be described by impulse response and frequency response in time domain and frequency domain respectively. The latter is expressed as a function with frequency as an independent variable. In general, it is a complex variable function with the complex variable jω as the independent variable, denoted by H(jω). Its modulus H (ω) and argument φ (ω) are functions of the angular frequency ω, which are called the "amplitude-frequency response" and "phase-frequency response" of the system, respectively. They respectively represent the amplitude change and phase change encountered when the signal components of different frequencies in the excitation source pass through the system. It can be shown that the "frequency response" of a system is the Fourier transform of the "impulse response" of that system. When the linear passive system can be expressed by an N-order linear differential equation, the frequency response H(jω) is a rational fraction, and its numerator and denominator correspond to the right and left sides of the differential equation, respectively.