microwave bench block diagram wikipedia

[Guest]

Hi am alina i would like to get details on microwave bench block diagram wikipedia ..My friend Justin said microwave bench block diagram wikipedia will be available here and now i am living at trivandrum and i last studied in the college/school .john cox college of engineering and i need help on this topic

[ashwiniashok]

Microwaves are a form of electromagnetic radiation with wavelengths ranging from one meter to one millimeter; with frequencies between 300 MHz (100 cm) and 300 GHz (0.1 cm).[1][2] This broad definition includes both UHF and EHF (millimeter waves), and various sources use different boundaries. In all cases, microwave includes the entire SHF band (3 to 30 GHz, or 10 to 1 cm) at minimum, with RF engineering often restricting the range between 1 and 100 GHz (300 and 3 mm).

The prefix micro- in microwave is not meant to suggest a wavelength in the micrometer range. It indicates that microwaves are "small", compared to waves used in typical radio broadcasting, in that they have shorter wavelengths. The boundaries between far infrared, terahertz radiation, microwaves, and ultra-high-frequency radio waves are fairly arbitrary and are used variously between different fields of study.

There is broad absorption from water vapor from several hundred MHz, increasing in frequency to 40 GHz. Beginning at about 40 GHz, even dry atmosphere becomes less transparent to microwaves, at higher frequencies due to absorption from oxygen. A spectral band structure at even higher frequencies causes absorption peaks at specific frequencies (see graph at right). Above 100 GHz, the absorption of electromagnetic radiation by Earth's atmosphere is so great that it is in effect opaque, until the atmosphere becomes transparent again in the so-called infrared and optical window frequency ranges.