NITTE MEENAKSHI INSTITUTE OF TECHNOLOGY,YELAHANKA,BANGALORE DEPARTMENT OF ELECTRONICS & COMMUNICATION ENGINEERING

ASSIGNMENT I REG NO 1NT 08EC001 TO 1NT O8EC0211.Find the field strength at 30 km away from a transmitting station of 25 kW power. 5M 2.Find the velocity of the plane wave in a lossless medium having a relative permittivity of 5 & relative permeability of unity. 3M 3.If the effective height of an aerial is 1/100th of the length of the wave emitted, Determine its radiation resistance. 4.Calculate the effective length of a /2 of antenna's=73, (Ae) max=0.132 and Intrinsic impedence=120. 5.Calculate the maximum effective aperture of an antenna which is operating at a Wavelength of 2 meter and has a directivity of 100. 6. What is the band width of a resonant circuit whose Q=100 and resonant Frequency=5MHz. 3M 3M 5M 5M

ASSIGNMENT II7.Calculate the length of the half wave dipole antenna meant to have correct half wave length at 60 MHz. 8. Find out the radiation resistance of a /16 wire dipole in free space. 3M 3M

9. The radiation resistance of antenna is 72 and loss resistance is 8.What is its directivity, if the gain is 16. 5M 10. A thin dipole antenna is /15 long.If its loss radiation resistance is 15, find radiation resitance and its efficiency. 5M

11. Find out the Q of an antenna if it has bandwidth of 600 Hz and it is cut to a frequency of 30 Mhz. 5M 12. An antenna has a radiation resistance of 72,a loss resistanse of 8 and a power gain of 12 db,determine the antenna efficiency and its directivity. 5M

REG NO:1NT 08EC022 TO 1NT 08EC043 ASSIGNMENT I13. A 6ft.(1.83m) paraboloid reflector is to be used at 6Ghz.Calculate the beam width between the first nulls. Also calculate the gain of the antenna and express it in db. 5M 14. An antenna having a effective temperature of 15K is fed into a microwave amplifier that has an effective noise temperature of 20K.Calculate the available noise power per unit bandwidth, at the input for this particular antenna temperature. 5M 15. The noise figure of an amplifier at room temperature (T=290K) is 0.2db.Find the equivalent temperature. 3M 16. In a microwave communication link, 2 identical antenna is operating at 10GHz are used with power gain of 40db.If the transistor power is 1W, find the received power if the range of the link is 30km. 5M 17. A short dipole antenna has got a radiation resistance of 73ohm & effective aperture of 0.5sqm. Find the effective height of the antenna. 18. A radio link has a 15W transmitter connected to an antenna of 2.5sqm effective aperture at 5GHz. The receiving antenna has an effective aperture of 0.5sqm & is located at a 15Km line of sight distance from the transmitting antenna. Assuming lossless matched antennas find the power delivered to receiver. 8M 5M

ASSIGNMENT II19.Calculate the maximum effective aperture of an antenna which is operating at a wavelength of 2 meter & has a directivity of 100. 3M 20. In a microwave communication link, two identical antennas are operating at 10GHz & are used with a power gain of 40dB. If the transmitter power is 1W. Find the received power if the range of link is 30km. 8M

21.An antenna has a radiation resistance of 72ohm & a loss resistance of 8ohm & a power gain of 12dB. Determine the antenna efficiency & directivity. 7M 22.Calculate the radiation resistance of a lamda/10 wire dipole in free space.7M 23.A hypothetical isotopic antenna is radiating in free space. At a distance of 100m from the antenna the total electric field E(theta) is measured to be 3.535V/m. Find the power density and power radiated. directivity if the power gain is 16. 5M 5M 24. The radiation resistance of an antenna is 72ohm & the loss resistance is 8ohm. Find the 25.For an X-band (8.2-12.4GHz) rectangular horn with aperture dimesions of 5.5cm & 7.4cm. Find the maximum effective aperture when its gain over isotropic source is a) 14.2dB at 8.2GHz b) 16.5dB at 10.3GHz c) 18.03dB at 12.4GHz d) Find the physical aperture also 2M 2M 2M 2M

REG NO :1NT 08EC044 TO 1NT 08EC070, 1NT 08EC123 ASSIGNMENT I26. Find the beam area of an antenna system that has electric field intensity pattern given by the expression En=sin() 0