In: Physics
Identify the type of radio wave propagation shown in
figure below: (1 mark )
Give any four characteristics (properties) of radio wave
propagation in the VHF band.
(2 marks )
Maximum line of sight distance between transmitting and receiving
antennas for a space
wave communication system is given as 45 km. The distance of the
horizon from the
transmitting antenna is 28 km. Calculate the height of the
receiving antenna in meters.
Distance between transmitting and receiving antennas is, d = 45 km = 45 * 10³ m
Distance of horizon from transmitting antenna is height of transmitting antenna, Ht = 28 km
Height of receiving antenna , Hr
Radius of earth, R = 6.4 * 10^6 m
Height of receiving antenna can be calculated by using formula,
Range = √ ( 2RHt) + √ ( 2RHr)
45 * 10³ = √ ( 2 * 6400 * 10³* 28 * 10³ ) + √( 2* 6400 *Hr)
45 * 10³ = √( 2*6400*40³)[√(28*10³) + √ Hr]
Hr = 23949 m = 23.949 * 10³ m
Or Hr = 23.949 km