Frequency, Wavelength and Phase of a signal

Frequency (f)

Frequency is defined as the number of cycles completed by the wave in one second i.e., number of cycles per second. Time period refers to the time taken by the wave to complete one second. Unit of frequency is Hz (Hertz).  Note that kHz, MHz, GHz, THz are used to measure higher frequencies.

1KHz   =  1 Kilo Hertz    =  103 Hz
1MHz   =  1 Mega Hertz    =  106 Hz
1GHz   =  1 Giga Hertz    =  109 Hz
1THz   =  1 Tera Hertz    =  1012 Hz

different frequecy and wavelength

Wavelength (l)

Definition 1: Distance between two identical points on successive cycles of a wave

Definition 2: Distance occupied by the electromagnetic wave (i.e., radio wave) during the one cycle time

Wavelength is usually expressed in meters. Note that very high frequency wavelengths are sometimes expressed in centimetres (cm).

As EM (Electro-Magnetic) waves travel at the speed of light in the free space (atmosphere), their wavelength is given by:

wavelength

Note that for an EM wave, wavelength = distance occupied by the signal during one cycle time in free-space. Therefore, the answer is 2 metres.

A simple sine wave and its parameters

The sine wave is the simplest form of an analog signal. It has three parameters: amplitude, frequency and phase. Phase describes the position of the waveform with respect to time (specifically relative to time 0). Below figure shows various phase differences (0o, 90o delay or advance) of same sine signal.

frequency

Gopal Krishna

Hey Engineers, welcome to the award-winning blog,Engineers Tutor. I'm Gopal Krishna. a professional engineer & blogger from Andhra Pradesh, India. Notes and Video Materials for Engineering in Electronics, Communications and Computer Science subjects are added. "A blog to support Electronics, Electrical communication and computer students".

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