Antenna and Array for 5G WiFi

Abstract

The project is to develop a set of wideband base station antennas for indoors Wi-Fi communication. It has to cater for distribution of end users over the indoors environment. Essentially, two types of base station antennas has to be developed: circular patch antennas 2.45GHz and 5.85GHz, and dual band square array. The circular patch antennas are generated conical omnidirectional radiation pattern for providing a wide coverage of Wi-Fi communication for end user being uniformly distributed over the whole area. The square dual band patch antenna array consists of eleven elements: four elements for 2.45GHz and seven element for 5.85GHz. They are responsible for generating powerful directional radiation patterns. Beam steering feature is incorporated to control the direction of radiation pattern so as to focus the radiation pattern to the direction where end users are highly concentrated. My proposed circular antenna is much thinner than traditional ones which generate omnidirectional radiation pattern: 3.17mm versus 31mm for 2.45GHz My proposed square 2.45GHz patch antenna has only 11.5mm in height, compared with 31mm for traditional antenna which generates similar radiation pattern as directional radiation pattern. Capacitance loading and proximity coupling is used so as to achieve about 22% of fractional impedance bandwidth in square patch antenna. Double resonance technique is used in the circular antenna so as to achieve more than 10% fractional impedance bandwidth. Binomial power distribution is used square dual band patch array to achieve side lobes suppression. The measurement results of the square dual band antennae shows the maximum gain of 6dBi and low cross polarization has been achieved. The measurement results shows that when square dual band patch array is used in conjunction a commercial 1 to 4 power divider, it can achieve about 77% fractional impedance bandwidth.