Abstract: The radiation field of electric dipole the far field radiation power of non-directional antenna and relationship between power and dimension secondly are presented.Two half wave antennas with different dimensions are compared based on Ansoft HFSS,S11 of return loss and far field pattern are changed with frequency or wavelength,the relationship between radiation and antenna operating frequency or wavelength are tested further.Practices show that these perceptual knowledge enhance the quality of teaching and obtain satisfied teaching effects partly.

Key words: high frequency structure simulator, D＇Alembert＇s equations, radiation power, return loss