射頻功率遠(yuǎn)程傳感器

　　捕獲的能量

　　最近，在能源收集領(lǐng)域取得了許多進(jìn)展。許多日常能源，如光、風(fēng)、溫度、振動(dòng)、無線電波，甚至是PH，都被巧妙地轉(zhuǎn)化為可用能源，使用各種技術(shù)（見圖1）。挑戰(zhàn)在于如何將這些技術(shù)產(chǎn)生的微小能量轉(zhuǎn)化為能夠發(fā)揮有用功能的形式，例如以可靠的方式為環(huán)境傳感器供電。

　　圖1：能量收集方法的功率密度。（來源：技術(shù)研究雜志）

　　關(guān)鍵是選擇收獲的來源和組成部分，并仔細(xì)分析功率預(yù)算。射頻能量作為其他采集技術(shù)的電源的優(yōu)點(diǎn)是可以從環(huán)境能量中獲得，或者通過專用發(fā)射機(jī)控制。利用射頻采集設(shè)備可以在幾乎任何環(huán)境中不受限制的工作。

　　RF as a power source

　　RF energy can be harvested from sources such as broadcast TV and radio stations， mobile phones and base stations， and transmitters in unlicensed bands including 915 MHz， 868 MHz， or 2.4 GHz， making RF harvesting commercially viable worldwide. RF enjoys many advantages over other energy sources. It does not depend on the time of day， does not require exposure to heat or wind， and can be moved freely within the range of the transmission source. It can be completely controlled， meaning that the energy can be transmitted continuously， on a scheduled basis or on demand. A rechargeable battery or super capacitor can be utilized to store the converted RF energy for operation during the peak periods.