A Slotted Coaxial Antenna as an Alternative to Wire Dipole Antennas

Miniaturization of antennas is nowadays a very important issue as they must flt into modern electronic systems with small dimensions. As a matter of fact, the use of CMOS technology in the RF and microwave ranges presents a great challenge to the traditional antenna designer, in reducing the radiant element in the same proportion as the rest of the circuit. The rapid advances achieved in the fleld of MEMS technology also enable the fabrication of very small circuits and systems. Since antenna dimensions are in general ruled by the resonant frequency and not by technological parameters, as for circuits, its design imposes severe constraints, when the dimensions are to be kept small. Here a slotted coaxial antenna is presented as an alternative to small radiant element antennas. The ISM band (2.45GHz) was chosen for the operational frequency, since it is a range in which normally wire dipoles are employed, in devices such as WiFi network cards and related equipments. Some advantages in comparison to dipole antennas are also discussed.