This book describes the satellite communication

EC8094

SATELLITE
COMMUNICATION
Course Instructor: M.Lingeshwaran M.E.,(Ph.D.)

, UNIT III
SATELLITE LINK DESIGN

▪ Basic link analysis
▪ Interference analysis
▪ Rain induced attenuation and interference
▪ Ionospheric characteristics
▪ Link Design with and without frequency reuse

, Equivalent Isotropic Radiated Power
▪ A key parameter in link-budget calculations is the equivalent isotropic radi
power, conventionally denoted as EIRP.
▪ The maximum power flux density at some distance r from a transmitting ante
of gain G is
𝐺𝑃𝑆
Ψ𝑀 =
4𝜋𝑟 2
▪ An isotropic radiator with an input power equal to 𝐺𝑃𝑆 would produce the s
flux density. Hence, this product is referred to as the EIRP.
𝐸𝐼𝑅𝑃 = 𝐺𝑃𝑆
▪ EIRP is often expressed in decibels relative to 1 W, or dBW. Let 𝑃𝑆 be in w
then
𝐸𝐼𝑅𝑃 = 𝑃𝑆 + 𝐺 dBW
where 𝑃𝑆 is also in dBW and [G] is in dB.

, Equivalent Isotropic Radiated Power
Example 3.1: A satellite downlink at 12 GHz operates with a transmit power of
and an antenna gain of 48.2 dB. Calculate the EIRP in dBW.
Solution:
𝐸𝐼𝑅𝑃 = 𝑃𝑆 + 𝐺 dBW
6
𝐸𝐼𝑅𝑃 = 10 log + 48.2 = 56 𝑑𝐵𝑊
1