Yu.B. Nechaev, I.V. Popov, E.S. Makarov

A six-sector switchable antenna array for wireless communications in 1.5-1.8 GHz band is developed and tested in this paper. Antenna was developed to provide highest possible gain while maintaining sidelobe level below -12 dBi. Six radiation patterns of antenna-s sectors cover 360° range, providing spatial diversity. Each sector of antenna array is a linear parallel-fed two-element subarray of rectangular microstrip radiators with circular arc slots and its size is 200x300mm. Parallel feed is provided by broadband power combiners with 0.8-2.5 GHz frequency band and three sol-id-state p-i-n diode switches are used to choose desired sector of antenna array. Control board on the basis of Atmega2560 from Atmel is developed for switch management and interfaces for Ethernet (up to 10 Мbit/s), USB (up to 480 Мbit/s), UART (up to 115 kbit/s) are provided to conjugate ar-ray with external devices. Resulting gain of antenna array is about 11 dBi taking into account switch, cables and combiner insertion losses. Antenna has vertical polarization, coupling between sectors no more than -20 dB and sector patterns overlap at the level of -3-4 dB depending on frequency.