This shows you the differences between two versions of the page.
Both sides previous revisionPrevious revisionNext revision | Previous revisionNext revisionBoth sides next revision | ||
faq:freedom-from-feedback [2015/04/05 17:00] – hess | faq:freedom-from-feedback [2015/04/21 16:22] – hess | ||
---|---|---|---|
Line 1: | Line 1: | ||
====== Freedom from Feedback ====== | ====== Freedom from Feedback ====== | ||
- | Deutsche Bahn requires a decoupling of up to -60 dBm. According to a simulation of one of our antenna supplier a distanec | + | |
+ | As a theoretical rule of thumb, a good decoupling requires a distance of 5 to 10 λ. (([λ] Lambda = Wave length)) | ||
+ | In practive, in most cases a distance of 3 λ is sufficient. \\ | ||
+ | \\ | ||
+ | < | ||
+ | & | ||
+ | </ | ||
+ | |||
+ | At 2.1 GHz (e.g. UMTS) the formula returns 300' | ||
+ | |||
+ | Three λ will then be 0.42m i.e. 42cm. | ||
+ | |||
+ | ===== GSM-R ===== | ||
+ | For GSM-R Deutsche Bahn requires a decoupling of up to -60 dBm. According to a simulation of one of our antenna supplier a distance | ||
Source: {{: | Source: {{: |