Design Of RF Bi-directional Amplifier For 2.4GHz Wireless Local Area Network

A bi-directional amplifier is studied and implemented for Wireless LAN (WLAN) in this thesis. The bi-directional amplifier consists of a logarithmic detector, power amplifier (PA), a low noise amplifier, RF switches and power controlling path, so as to extend the scope of Access Point and Wireless LAN. The power controlling path is used to maintain the output power 27dBm,and to switch it on Tx or Rx, the working principle will be explicated in detail in this paper. ATF34143 and MGF0919A are used to realize power amplifying, the output power is about 27.5dBm, P1dB is about 32dBm. ATF-34143 is also used to realize a low noise amplifier. The gain and noise figure of the LNA are about 14dB and 1.0 dB respectively. In the transmitting mode, the startup level is OdBm, the input dynamic range is 16dB, the output power reaches 27dBm allowing for the loss of the T/R switch, and the power spectrum satisfies the spectrum mask of IEEE802.11b. In the receiving mode, 12dB gain and 3.7dB noise figure are achieved.