| 摘要 |
An antenna system, having application to low power license exempt wireless local area networks (WLAN), such as Bluetooth and IEEE 802.11A. The system has a first antenna 15 for transmitting and a second antenna 16 for receiving, the second antenna having higher gain than the first. A signal detector 18 may be provided which causes a transmit/receive switch 13 to operate. The effective isotropic radiated power output (EIRP) of the first antenna is preferably less than 100 mW. Alternatively, a common antenna may be used for both receiving and transmitting. In this case an attenuator limits the power of the transmission, but not the reception. Also disclosed is an apparatus for electromagnetically coupling an external antenna to an existing wireless device having an integrated antenna. |
