The unguided transmission of information using electromagnetic waves
at radio frequency (RF) is often referred to as wireless communications,
the first demonstration of which took place at the end of the 19th cen-
tury and is attributed to Hertz. The technology was, shortly thereafter,
commercialise ...
/dl/522097.html
标签:
Imperfections
RF
上传时间:
2020-06-01
上传用户:shancjb