Low-profile compact-size electronically beam-switching antenna for wireless communications

This paper presents a novel compact-size low-profile low-cost smart antenna which could electronically switch the beam for radiating towards different directions covering the full range of 360 degree in the azimuth plane. Through DC control of the on/off status of four embedded PIN diodes sequentially, the antenna can switch its beam in sequence towards different directions. It is able to achieve a bandwidth over 22% and the antenna gain over 3 dBi under all kinds of states of four PIN diodes. Meanwhile, it can achieve a front to back ratio (FBR) of over 15 dB. Compared to other low-cost smart antennas reported, the height of this antenna has been significantly reduced and its main advantages include low profile, compact size, planar structure, low cost and the capability of covering the full range of 360 degree in the azimuth plane through electronically control of PIN diodes. It is promising for application in wireless communication systems.