RF Cafe Software
About RF Cafe
1996 - 2016
BSEE - KB3UON
RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The Internet was still largely an unknown entity at the time and not much was available in the form of WYSIWYG ...
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The following equations and images describe electromagnetic waves inside both rectangular waveguide and circular (round) waveguides. Oval waveguide equations are not included due to the mathematical complexity.
Click here for a transmission lines & waveguide presentation.
A Cavity Resonance Calculator is included in RF Cafe Calculator Workbook for FREE.
The lower cutoff frequency (or wavelength) for a particular mode in rectangular waveguide is determined by the following equations (note that the length, x, has no bearing on the cutoff frequency):
This example is for TE1,0 (the mode with the lowest cutoff frequency) in WR284 waveguide (commonly used for S-band radar systems). It has a width of 2.840 1.340"(3.404 cm).
TE (Transverse Electric) Mode
The TE10 mode is the dominant mode of a rectangular waveguide with a>b, since it has the lowest attenuation of all modes. Either m or n can be zero, but not both.
____ Electric field lines
TM (Transverse Magnetic) Mode
For TM modes, m=0 and n=0 are not possible, thus, TM11 is the lowest possible TM mode.
____ Electric field lines
|TE (Transverse Electric) Mode|
The lower cutoff frequency (or wavelength) for a particular TE mode in circular waveguide is determined by the following equation: , where p'mn is
|TM (Transverse Magnetic) Mode|
The lower cutoff frequency (or wavelength) for a particular TM mode in circular waveguide is determined by the following equation: (m), where pmn is
Related Pages on RF Cafe
- Properties of Modes in a Rectangular Waveguide
- Properties of Modes in a Circular Waveguide
- Waveguide & Flange Selection Guide
- Rectangular & Circular Waveguide: Equations & Fields
- Rectangular waveguide TE1,0 cutoff frequency calculator.
- Waveguide Component Vendors
- Waveguide Design Resources
- NEETS - Waveguide Theory and Application
- EWHBK, Microwave Waveguide and Coaxial Cable