Rectangular Waveguide Cut-off Frequency Calculator

Enter the width of the Waveguide broad wall to get the cut-off frequency and operational frequency of the Waveguide. A list of the waveguide sizes can be see on everything RF - Waveguide Size List.

Calculate the Waveguide Cut-off Frequency


  • fc (GHz):
  • f1 (GHz):
  • f2 (GHz):
Formula for Rectangular Waveguide Cut-off Frequency Calculator

Rectangular Waveguide Cut-off Frequency Calculator

A waveguide is a hollow metallic structure used to transfer electromagnetic waves from one place to another. A waveguide with a rectangular cross-section is known as a rectangular waveguide. The rectangular waveguide supports both TE (transverse electric) and TM (transverse magnetic) modes. In a rectangular waveguide, TE10 mode is the dominant mode, i.e., at this mode, the electromagnetic wave propagates with a minimum loss or minimum degradation.   

Rectangular waveguides will only carry or propagate signals above a certain frequency, called the cut-off frequency. Below this frequency, the signals will be attenuated.

This online rectangular waveguide calculator calculates the cut-off frequency f(GHz), lower operational frequency f1 (GHz) & higher operational frequency f2 (GHz) of a rectangular waveguide by entering the broad wall width W (mm/cm/Inch/m). 

What is rectangular waveguide?

A rectangular waveguide is a conducting metallic cylinder with a rectangular cross-section used for the propagation of electromagnetic waves. It is used to conduct the radio waves at frequencies from 3 to 30 GHz and higher. They operate in TE and TM mode and T10 mode is the dominant mode. They are primarily used in stubs, quarter-wave transformers, directional couplers, and taper sections along with radars and radio communication systems.

How to calculate Cut-off Frequency, lower & higher operational frequency  of a rectangular Waveguide?

The following formula is used to calculate the cut-off frequency, lower & higher operational frequency of the rectangular waveguide.


fc = Cut-off frequency of rectangular waveguide in GHz

f1 = Lower operational frequency in GHz

 f2 = Upper operational frequency in GHz

C = Speed of light

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