Hãy chắc chắn rằng các bộ khuếch đại bạn mua đi kèm với một báo cáo hiệu chuẩn và chứng nhận. Bạn chỉ có thể tham khảo thủ tục giấy tờ này mỗi năm một lần, nhưng đó là một ý tưởng tốt để lưu trữ nó trong vị trí thích hợp trong trường hợp báo cáo là bao giờ cần thiết. | 125 Chapter 5 - Antennas and Accessories Make sure that the amplifier you purchase comes with a calibration report and certificate. You may only refer to this paperwork once a year but it s a good idea to store it in the proper location in case the report is ever needed. RF amplifiers should be calibrated once per year to assure continued accuracy and performance. Configuration Management RF amplifiers used with wireless LANs are installed in series with the main signal path as seen below in Figure . Amplifiers are typically mounted to a solid surface using screws through the amplifier s flange plates. Configuration of RF amplifiers is not generally required unless the amplifier is a variable RF amplifier. If the amplifier is variable the amplifier must be configured for the proper amount of amplification required according to your RF math calculations. The manufacturer s user manual will explain how to program or configure the amplifier. FIGURE RF amplifier placement in the wireless LAN system Access Point Amplifier Variable amplifiers are not recommended because the settings could inadvertently be changed resulting in damage to the antenna or a violation of FCC rules governing output power in the ISM or UNII bands. Fixed RF amplifiers are recommended and the RF calculations should be done ahead of time to make sure the RF signals will be within FCC guidelines. After the calculations are complete and the necessary amount of amplification is known then the RF amplifier should be purchased. RF Attenuators An RF attenuator is a device that causes precisely measured loss in -dB in an RF signal. While an amplifier will increase the RF signal an attenuator will decrease it. Why would you need or want to decrease your RF signal Consider the case where an access point has a fixed output of 100mW and the only antenna available is an omni-directional antenna with 20 dBi gain. Using this equipment together would violate FCC rules for power output so an attenuator .
