Compact low-cost smart antenna for wireless communications

In this paper, a compact low-cost electronically beam-scanning smart antenna that covers the frequency band from 2.45 GHz to 2.55 GHz is proposed. The driven element is a directional antenna composed of three Inverted F-type Antenna (IFA) elements. In addition to the driven element, there are twelve IFA parasitic elements arranged around the driven element and loaded with varactors. By tuning the DC voltages applied to the varactors, each parasitic IFA antenna element can be reconfigured either as a reflector or a director. This provides the scanning mechanism for the beam. The proposed antenna has a radius of 50 mm and a height of 40 mm. Compared with other beam-switching smart antennas, the antenna is smaller in size and lower in cost, while still achieving a gain of 10.5 dBi.