1

GATE ECE 1999

Subjective

+5

-0

A 100 m section of an air-filled rectangular wave-guide operating in the $$T{E_{10}}$$ mode has a cross-sectional dimension of 1.071 cm $$ \times $$ 0.5 cm. Two pulses carriers of 21 GHz and 28 GHz are simultaneously launched at one end of the wave-guide section. What is the time delay difference between the two pulses at the other end of the waveguide?

2

GATE ECE 1998

Subjective

+5

-0

A rectangular waveguide with inner dimensions 6 cm $$ \times $$ 3 cm has been designed for a single mode operation. Find the possible frequency range of operation such that the lowest frequency is 5% above the cut off and the highest frequency is 5% below the cut off of the next higher mode.

3

GATE ECE 1998

Subjective

+5

-0

The region between a pair of parallel perfectly conducting planes of infinite extent in the y and z directions is partially filled with a dielectric as shown in Figure. A 30 GHz $$T{E_{10}}$$ wave is incident on the air dielectric interface as shown. Find the
VSWR at the interface.

4

GATE ECE 1996

Subjective

+5

-0

In an air-filled rectangular waveguide, the vector electric field is given by
$$\mathop E\limits^ \to = \cos \,(20\,\pi \,y)\,\exp \,\,\left[ { - j\left( {{{40\,\,\pi } \over 3}} \right)\,z\, + j\,\omega \,t} \right]\,\hat i\,\,\,V/m$$

Find the vector magnetic field and the phase velocity of the wave inside the waveguide.

Questions Asked from Waveguides (Marks 5)

Number in Brackets after Paper Indicates No. of Questions

GATE ECE Subjects

Signals and Systems

Representation of Continuous Time Signal Fourier Series Discrete Time Signal Fourier Series Fourier Transform Discrete Time Signal Z Transform Continuous Time Linear Invariant System Transmission of Signal Through Continuous Time LTI Systems Discrete Time Linear Time Invariant Systems Sampling Continuous Time Signal Laplace Transform Discrete Fourier Transform and Fast Fourier Transform Transmission of Signal Through Discrete Time Lti Systems Miscellaneous Fourier Transform

Network Theory

Control Systems

Digital Circuits

General Aptitude

Electronic Devices and VLSI

Analog Circuits

Engineering Mathematics

Microprocessors

Communications

Electromagnetics