QUESTION 1
(a) By referring to frequency allocations for satellites
(i) Discuss five services provided by satellite systems
(ii) Two of the frequency bands designations in common use for satellite services are Ku and L bands. What are these bands?
(b) By referring to artificial satellites orbiting the earth
(i) Define the following three parameters used in satellite communication: perigee, eccentricity and eccentric anomaly
(ii) As per Kepler's third law, prove that the square of the orbital period is directly proportional to the cube of the distance from the earth centre
(c) For a given satellite system
(i) Calculate the apogee and perigee heights for the orbital parameters given that the value of eccentricity is 0.0011501
(ii) Determine the angle of tilt required for a polar mount antenna used with an earth station of latitude 49o North. The distance from earth centre to the satellite is 42164 km
(d) Draw a label diagram of a GSM system architecture, describing the subsystems involved
QUESTION 2
(a) Derive an equation for the calculation of the spurious free dynamic range of a system in terms of the third order intercept point and the system noise power.
(b) Find the third order intercept point of a system of noise power of 5.11 dB and with a first order power of 8.11 dB.
(c) Consider a Butterworth lowpass filter of order 3 and cut-off frequency (wc) of 1.
(i) Derive the filter transfer function (H(s)) by computing the poles of the system.
(ii) Transform the filter by computing the components values so that it works for 3G systems at a frequency of 2GHz and system impedance 120 Ω.