University:
Santa Fe College
Course:
ETS 2527C | Electromechanical Components and Mechanisms
Academic year:

2024
Views:

438

Pages:

5
Author:

Jabin F.

Cut-off frequency of waveguide: (f_{c_{mn}} = -\frac{c}{2}\sqrt{(\frac{m}{a})^{2}+(\frac{n}{b})^{2}}) (w_{c_{mn}} = C\Pi\sqrt{(\frac{m}{a})^{2}+(\frac{n}{b})^{2}}) Wave vector in a waveguide: (K = \frac{1}{c}\sqrt{\omega^{2}-\omega_{c}^{2}}) If K is real ((\omega > \omega_{c})): (L0) = frequency of incident signal (w_{c}) = cut-off frequency Wave can transmit through waveguide. If K is imaginary ((\omega < \omega_{c})): Wave cannot propagate through waveguide. Dispersion relation for free space: (K = \frac{i}{c}w \Rightarrow \frac{\omega}{k} = c) (L0_{c} = 0) Dispersion relation for dielectric: (w_{c} = 0) (K = \frac{w}{v} \Rightarrow \frac{w}{k} = v) Dispersion relation for metals: (w_{c} = w_{0}p) (K = \frac{i}{c}\sqrt{w^{2}-\omega_{c}^{2}}) Dominant mode: It is the mode that has the lowest cut-off frequency. Cut-off frequency of waveguide: ((f_{c})_{mn} = \frac{c}{2}\sqrt{(\frac{m}{a})^{2}+(\frac{n}{b})^{2}}) (mn \uparrow, f_{c} \uparrow) If dielectric filled waveguide: TE00: (X) TE10: ((f_{c})_{10} = \frac{c}{2a}) TE01: ((f_{c})_{01} = \frac{c}{2b}) If a > b: TE10 is dominant. If a < b: TE01 is dominant. v) TE00: (X) TE10: ((f_{c})_{10} = \frac{c}{2a}) TE01: ((f_{c})_{01} = \frac{c}{2b}) If a > b: TE10 is dominant. If a < b: TE01 is dominant. Cut-off wavelength: (\lambda_{c_{mn}} = \frac{c}{f_{c_{mn}}} = \frac{2\pi}{\sqrt{(\frac{m}{a})^{2}+(\frac{n}{b})^{2}}}) Highest cut-off wavelength mode is the dominant mode.