STUPIDSID
1 (a)
Discuss principle of pattern multiplication with example.
5 M
1 (b)
Show that the directivity of an isotropic antenna is unity, At what distance from 50 cycle circuit is radiation field approximately equal to induction field.
5 M
1 (c)
Draw electric equivalent for high frequency resistor. Inductor and capacitor.
5 M
1 (d)
Explain the working of principle of folded dipole antenna. What are advantages and applications.
5 M
2 (a)
Derive radiation resistance of infinitesimal dipole Explain its significance.
10 M
2 (b)
Why Yagi Uda antenna is called parastic array. Why radiation pattern of this array is unidirectional.
10 M
3 (a)
Define image impedance. Design a composite high pass filter by image parameter method with following specifications.
Cut off frequency : 50 Mhz
Infinite attenuation: 48 Mhz
Pole:
Characteristic impedance Ro=75 ?
Cut off frequency : 50 Mhz
Infinite attenuation: 48 Mhz
Pole:
Characteristic impedance Ro=75 ?
5 M
3 (b)
When is a dipole called Herzian dipole. Explain how the radiation pattern of folded dipole can be modified with addition of directors & reflectors.
5 M
3 (c)
Explain radiation mechanism, by showing that a parallel wire can act as source of radiation. Calculate radiation resistance of \[ \dfrac {\lambda } {10} \] dipole in free space.
5 M
4 (a)
Derive Friss transmission formula. State its significance in wireless communication. What is maximum power received at a distance of 0.5 km over free space for 10Hz frequency. The system consists of transmitting antennas with 2.5dB gain and receiving antenna with 20dB gain & antenna is fed with 150 W power.
10 M
4 (b)
Derive array factor N-cement linear array, where all elements are equally fed and spaced. Also find the expression for the position of principle maxima, nulls & secondary maxima.
10 M
5 (a)
Design a low pass filter with cut off frequency of 200MHz and attenuation of 50dB at 250 MHz. The flatness of filter response is not a design consideration. Choose the filter implementation that requires least number of components.
10 M
5 (b)
What are binomial arrays. Give their significance.
10 M
6 (a)
Explain important features of loop antenna. Discuss use of loop antenna in radio direction finding.
8 M
6 (b)
Draw & explain log periodic antenna. Why is it called so. Discuss advantages.
6 M
6 (c)
Explain horn antenna with reference to its working, antenna field & applications.
6 M
More question papers from RF Modelling and Antennas