### Understanding Antenna efficiency

Posted:

**Wed 29 Sep 2021, 11:51**Hi All,

On many example scripts the antenna efficiency is given as

disp( ['efficiency: nu_rad = ' num2str(100*nf2ff.Prad./P_in_0) ' %']);

where P_in_0 is the power in at the frequency of interest and calculated from port.P_acc accepted power.

nf2ff.Prad is the total radiated power from the antenna.

My questions are:

1) What decides the actual power level going into the simulation? when I run simulations I am getting levels as low as:

Accepted power P_in_0 = 9.7583e-28Watt

radiated power: Prad = 1.1931e-28 Watt

These seem very low power levels. Are such low levels correct? I assume they are derived from the initial Gaussian excitation is this correct?

2) Does the efficiency calculation include the mismatch between the lumped port and the antenna as well as the losses in the antenna?

3) I assume you have to ensure the frequency chosen is actually the resonant antenna frequency.

Many Thanks,

MPC

On many example scripts the antenna efficiency is given as

disp( ['efficiency: nu_rad = ' num2str(100*nf2ff.Prad./P_in_0) ' %']);

where P_in_0 is the power in at the frequency of interest and calculated from port.P_acc accepted power.

nf2ff.Prad is the total radiated power from the antenna.

My questions are:

1) What decides the actual power level going into the simulation? when I run simulations I am getting levels as low as:

Accepted power P_in_0 = 9.7583e-28Watt

radiated power: Prad = 1.1931e-28 Watt

These seem very low power levels. Are such low levels correct? I assume they are derived from the initial Gaussian excitation is this correct?

2) Does the efficiency calculation include the mismatch between the lumped port and the antenna as well as the losses in the antenna?

3) I assume you have to ensure the frequency chosen is actually the resonant antenna frequency.

Many Thanks,

MPC