Harmonics
Contents
What is a harmonic?
A harmonic of a particular frequency (the fundamental frequency f) is a frequency that is an integer multiple of the first one. For example:
if f = 125 MHz, the harmonics would be:
1st harmonic = 1f = 125 MHz
2nd harmonic = 2f = 250 MHz
3rd harmonic = 3f = 375 MHz
4th harmonic = 4f = 500 MHz
..... etc.
In the diagram below it can be seen that harmonics share common nodes.
Mathematically, the basic wave equation is:
<math> \mathit{v}=\mathit{f}\times \lambda </math>
v is the velocity of the wave in metres per second - a constant close to the speed of light for radio waves in the atmosphere.
f is the frequency of the wave - how many cycles pass a fixed point per second
<math> \lambda </math> is the wavelength of the wave in metres - the distance between two peaks of the wave.
So, as the frequency increases, the wavelength decreases - a doubling of frequency causes a halving of wavelength etc.
Where do harmonics come from?
Why are harmonics bad?
How do you get rid of harmonics?
External links
See also
Electronic Theory | |
Physical quantities | Current * Gain * Impedance * Power * Q of a circuit * Radiated Power Measurement * Reactance* Resistivity * Resonance * Voltage |
Components | Baluns * Bipolar-Junction Transistors * Capacitors * Diodes * Inductors* Lasers * Microphones * Resistors * Transformers * Wire |
Circuits | Attenuators * Digital Signal Processing (DSP) * Dummy load * Filters * LC filters * Power Supply Design * Rectifier Circuits |
Design | Amplifier Design * Oscillator Design |
Electromagnetic Waves | Relative power (Decibels) * Harmonics * Interference and BPL |