We Know,
e = Ec cosωct + MEc/2 cos(ωc+ωs)t+MEc/2 cos(ωc-ωs)t
Carrier Power, PC = (Ec/√2)2/R
= Ec2/2R……………1
Total Power Sideband,Ps = (MEc/2√2)2
= M2Ec2/8R…………2
PSB = M2Ec2/8R+M2Ec2/8R
=M2Ec2/4R
Total Power, PT = PC + PSB
= Ec2/2R+M2Ec2/4R
= Ec2/2R(1+M2/2
PT= PC(1+M2/2).............3
At Maximum efficiency, m=100% Or m=1
η = PSB/PTx100%