MODERN PRESENTATION

CIRCULAR WAVEGUIDECAVITY RESONATORS

MADE BY :Sarah ashraf nohammed Sherouk Ragab elsayed Doha bastawi ahmed

table of content :

- Defenation and modes of propagation . - Shape of electromagnetic waves in different modes . - Equations of TE,TM modes . - Resonance frequency modes . - Advantages and Applications of Circular waveguide cavity resonators . -References .

what is and modes of propagation

circular cavity resonator can be constructed from a circular waveguide cutting into a section and shorting both he ends of it. The circular cavity resonators are mainly used in microwave frequency meters. The mechanical tuning of the resonant frequency is done with the help of movable top wall. The cavity is coupled to a waveguide through a small aperture. The dominant mode in case of the circular cavity resonator is given by TE111 . In general, the circular cavity resonator modes are specified as TMnmp, for the transverse magnetic (TM) wave and TE nmpfor the transverse electric (TE) wave.

Shape of propagation modes and expression of each mode

Note that both the ends of the section of circular cavity resonators of lenght 'd' are shorted with the help of circular shorting plates.The boundary conditions for circular waveguide are Ez= 0 for TE and Hz = 0 for TM , the bound condition along Z-direction for the two end walls also has to be satisfied

The transverse electric fields (te ,tm ) of the TEnm or TMnm circular waveguide mode : The resonating frequency of a TEnml resonant mode is given by : and the resonating frequency of a TMnml resonant mode is given by :

advantages and applications

Circular waveguide cavity resonators offer several advantages over other types of resonators. They have a higher Q-factor, which means they have a narrower bandwidth and can be used in applications that require high selectivity. They also have lower insertion loss, which means they can be used in applications that require high efficiency. Circular waveguide cavity resonators are also easy to fabricate and can be made in a variety of sizes and shapes. They are commonly used in filters, oscillators, and amplifiers. They can also be used in antenna systems, microwave radiometers, and cavity-backed slot antennas. Circular waveguide cavity resonators are particularly useful in high-frequency applications where low insertion loss and high selectivity are important.

References :

" Transmission Lines & Waveguides Uday A. Bakshi ، Late Ajay V. Bakshi " . " FUNDAMENTALS OF MICROWAVE ENGINEERING PRINCIPLES, WAVEGUIDES, MICROWAVE AMPLIFIERS AND PRINCIPLES, WAVEGUIDES, MICROWAVE AMPLIFIERS Singh Anoop ،verma Seema " .

thanks