How can I model an antenna in a RF circuit?

Hi

How can I model the antenna in a RF circuit . How should I take the effect of an antenna into account in a circuit ?

hi
antenna can be modeled as and R,L,C element connected at the output of the TX or the input of the RX.
Values of R,L,C varies according to frequency of operation, type of antenna, specs of antenna.

You can find equivlen RLC of an antenna by using EM simuators

Thanks
Haytham

are there any good books on Antenna modeling