Discuss the operating principle of Faraday’s rotation isolator.

In 1845 Michael Faraday demonstrated that the plane of polarization of a linearly polarized light is rotated when it passes through ferrite materials along the direction of applied magnetic field. This is true for microwave also.

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Can a circulator be used as an isolator? If so, how? Difference between circulator and isolator

Circulator can be separated into two classes, 4 port waveguide circulators based on Faraday rotation of waves propagating in a magnetized material and 3 port Y junction circulators based on cancellation of waves propagating over two different paths near a magnetized material. A circulator can also be used as an isolator.

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An air filled rectangular waveguide of inside dimensions 7 X 3.5 cm2oprtates in the dominant mode TE₁₀

• Find the cut-off frequency
• Determine the guide wavelength of 3.5 GHz

The cut-off frequency in the dominant mode is

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Find out the expressions for the different components of electric and magnetic fields inside a rectangular waveguide for TE mode of propagation. Hence find out the expression for the guide wavelength and propagation constant.

In order to study transmission lines electromagnetically, one should know the laws governing time varying electromagnetic fields. The interaction between charges and their mutual energy is expressed in terms of four vectors E and B, D and H. The first pair defines the factor on a charge density ρ moving with vector v given by;

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A multi hole directional coupler is fed with single power of 2.8 mW at 10 GHz. The coupling factor is 3 dB and the directivity is better than 40 dB over X-band range. Find the distribution of power at all other ports.

The expression for coupling factor is

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The dominant mode TE₁₀ is propagated in a rectangular waveguide of dimensions a=6 cm, b=4 cm. The distance between two successive minima is 4.47 cm. Determine the signal frequency.

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When a dominant mode is propagating in an air filled rectangular waveguide, the guide wavelength for a frequency of 9 GHz is 4 cm. Calculate broad wall dimension of the guide.

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