A practical high gain dual-band antenna for ISM systems

Dual-band antennas are of a relative interest since they can support multiple communication systems. Among other advantages are their small sizes and low cost, since only one antenna is shared. In this paper a dual-band antenna is presented, operating in the two industrial scientific and medical bands of 2.45 GHz and 5.8 GHz. The return loss measured is in all frequency bands, better than 10 dB. Their optimum design permits them to have a High Gain of +5.9 dBi at 2.45 GHz and +4 dBi at 5.8 GHz. They consist of two strip dipoles, the arms of which are printed on opposite sides of an electrically thin dielectric substrate. Thus they have a simple structure, allow them to be cheaply manufactured using printed circuit board technology.