APPARATUS FOR RECEIVING AND TRANSMITTING RADIO SIGNALS

摘要

The present invention relates to an antenna unit for transmitting and receiving radio signals having two different polarizations. The antenna unit (140) comprises a slot integrated in a microstrip element (143) and an aperture (141) integrated in a conductive surface (142) on the microstrip element (143). The aperture (141) is arranged in the conductive surface (142) parallel to its polarization direction. The slot is arranged in an underlying layer directly below the aperture (141). The conductive surface (142) of the microstrip element (143) is arranged to transmit or receive with a vertical polarization and a first horizontal beam width. The slot is arranged to transmit or receive with a horizontal polarization and a second horizontal beam width. The second beam width is substantially equal to the first beam width. The antenna unit (140) is very compact and light and only causes low power losses. A number of antenna untis (140) can be used to design sector antennas or antenna arrays.