8. (6 points) A Hertzian dipole antenna in free space has /= 0.02. The following are in far-field: (a) What value of cu...
9. (6 points) An antenna engineer is asked to design a X/2 dipole antenna to operate at 450 MHz. (a) Calculate the length of the antenna if it is located in free space. (b) Calculate the magnetic field intensity, H, at a distance of 400km, polar position 0 = 30 degrees and current I = 2A (c) What value of the current I is needed for the total radiated power to equal 100 mW. (d) Determine the length of the...
Solve the following: a. Compare the current required to radiate 10W from a Hertzian dipole of length 0.12 and a current loop of radius 0.12. b. An isotropic antenna is radiating in free space. At a distance of 100m the antenna the field measured is 1V/m. i) Find the power density at this location; ii) Determine the total power radiated by the antenna
1) A Hertzian dipole antenna is a short conducting wire carrying an approximately constant current over its length If such a dipole is placed along the z-axis with its midpoint at the origin, and if the current flowing through it is i(t) ż lo cosot, assume I to be sufficiently small so that the observation point is approximately equidistant to all points on the dipole; that is, assume RR then the corresponding magnetic field is described by: olk2 sin e...
Question 1 The power radiated by a lossless antenna is 10 watts. The directional characteristics of the antenna are represented by the radiation intensity of U = 2cos3θ watts/unit solid angle. Find the (a) Maximum power density at a distance of 1000 m (assume far-field distance) (b) Maximum directivity (c) Maximum gain Question 2 In target-search ground-mapping radars it is desirable to have echo power received from a target, of constant cross section, to be independent ofits range. For one such application, the desirable radiation intensity...
11.12 The amplitude of the electric field intensity of a half-wave dipole antenna at r 5 km and /6rad is 0.01 V/m in free space. If the operating frequency is 30 MHz, determine its length and the total power that it radiates. Alse, write express 11.12 The amplitude of the electric field intensity of a half-wave dipole antenna at r 5 km and /6rad is 0.01 V/m in free space. If the operating frequency is 30 MHz, determine its length...
The approximate far zone normalized electric field radiated by a resonant linear dipole antenna used in wireless mobile units, positioned symmetrically at the origin along the z- axis, is given by 0°0 180° 1.5 ejkr EaâgEa sin 0° e 360° where E is a constant and r is the spherical radial distance measured from the origin of the coordinate system. Determine the: (a) Exact maximum directivity (dimensionless and in dB) (b) Half-power beamwidth (in degrees) (c) Approximate maximum directivity (dimensionless...