Table of contents
4. Relationship between analog angular frequency domain and digital domain frequency
1. Dimension
(1) Dimension is a physical property
(2) Dimension composition: quantity (number) + unit of measurement, that is to say, dimension has different units of measurement.
Such as quality: 1g/1kg/1mg
(3) Common dimensions: length, mass, time, temperature,
2. Dimensionless
(1) Definition: A physical quantity without a unit can be regarded as a scalar quantity, a ratio, etc. Usually, the dimension can be obtained by eliminating the units through the ratio.
(2) Dimensionless: angle, radian , slope, gain
(3) Understand angles and radians
Definition of angle: Two rays are emitted from the center of the circle to the circumference, forming an included angle and an arc opposite to the included angle. When the length of this arc is exactly equal to 1/360 of the circumference, the angle between the two rays is 1 degree.
Definition of radians: Two rays are emitted from the center of the circle to the circumference, forming an arc with an included angle and an included angle. When the arc length is exactly equal to the radius of the circle, the angle between the two rays is 1 radian.
3. The concept of frequency
The number of times a substance completes periodic changes in unit time is called frequency, and the unit is Hz, which is represented by the symbol f.
4. Relationship between analog angular frequency domain and digital domain frequency
4.1 Analog angular frequency
4.2 Digital angular frequency
