Calculate antenna gain, if power backscattered by antenna (Ps) is 25 percent of power transmitted (Pt) and assuming the proportional area intercepted by the target is half the area of a sphere with radius equal to range, R. 2.0 1/2 4.0 1/4

Consider a half-wave dipole that is radiating into free space when the origin is at the centre of the dipole and its axis is aligned with the z axis. The input power fed to the dipole is 300 W. If we assume that the dipole has an efficiency of 75%, calculate the power density at point P(r,θ,φ) of the spherical coordinate system with r = 300 m, θ=75° and φ=45°.

A radiated power of 5 W is produced by a resonant antenna. Its directional radiation intensity represented by: U = B0cos3θ (W/unit solid angle)    0 ≤ θ ≤ π/2;  0 ≤ ϕ ≤ 2πFind the(a)    maximum power density (in W/m2) at a distance of 1500m (assuming far field distance).(b)    Directivity of the antenna (dimensionless and in dB)(c)    Gain of the antenna with an efficiency of 85% (dimensionless and in dB)

Assume that the antenna gains of BS and MS are 6 dBi and 2 dBi, respectively. Corresponding antenna heights are 10 m and 1.5m, respectively and they operate in an environment where the ground plane can be treated as perfectly conducting. The BStransmits with a maximum of 40W and the MS with a power of 0.1W. The center frequency `of the links (duplex) are both at 900MHz, even if uplink and downlink frequencies differ from each other. Using plane-earth propagation assumption,a. Calculate how much received power is available at the output of the BS and MS receive antennas, as a function ofdistance d.b. Assuming that the receiver sensitivity of both BS and MS is −140 dBW, examine the range of the downlink and theuplink?c. In order that the range of the uplink and the downlink be the same, interpret the relation between the sensitivities of theBS and MS receivers?d. If the BS antenna height is lowered to 10 m, examine the effect on reception in terms of distance?

At a distance of 20 m from a hypothetical isotropic antenna is radiating in free space, the total electric field (Eθ) is measured to be 1.5 V/m. Find the(a)    power density (Wrad) and(b)    power radiated (Prad)

The figure above shows the radiation pattern of an antenna in linear scale.a). If the main lobe magnitude is 4.1, calculate the magnitude of its half power point. b). If the main lobe magnitude is 7 dB, calculate the magnitude of this new half power