Patent ID: 7583239

Claim:
A wireless communications device for use in a low-power wireless data communications system using a sub-millimeter wave band, wherein the system selectively uses a plurality of planes of polarization to have an increased number of effective channels, the device comprising: a directional antenna set on the planes of polarization having the highest number of non-occupied channels by detecting the number of non-occupied channels on each plane of polarization the directional antenna having a cross-polarization discrimination that is not less than 24 dB; and a first boss and a second boss protruded from a rear surface of the wireless communications device, wherein an antenna fixing part having a first hole and a second hole formed therein is fixed to the rear surface of the wireless communications device in a manner that the first and the second boss are inserted into the first and the second hole, respectively, the second hole being formed in such a shape as to allow the wireless communications device to be rotated at 90° about the first boss as a rotational axis while the first and the second boss are inserted in the first and the second hole.