# Satellite Communications/LNA Input Level

Question
What's the typical rf input level of a Ku Band LNA?

Hi Isidore,

Reading a typical datasheet, one can see (for example) gain = 50 dB and P1dB = +10 dBm.
In this case the maximum aggregate (total) input power is +10 - 50 = -40 dBm.
In order to operate linear, it is advised to work 10 dB away from this 1 dB compression point.
So in this case I would target a maximum input power of - 50 dBm.

The minimal power at the input will depend on the dynamic range of the receiver that is connected. Typically this is about 50 dB so an input power between -50 and -100 dBm would be ok. Of course this is total aggregate power and assuming that when the input power at the LNA is - 50 dBm, the receiver's input level is maximal. This will in term depend on the loss of cables and gain of the downconverter.

Hope this helps,

Dave
Questioner's Rating
 Rating(1-10) Knowledgeability = 10 Clarity of Response = 10 Politeness = 10 Comment Thank you, DAve... Does it affect the operation if the input is -100 or -90?

Satellite Communications

Volunteer

#### Dave Suffys

##### Expertise

Questions related to design of satellite communication links.

##### Experience

Satellite communication, link budgets, DVB-S2, ACM

Organizations
Newtec

Education/Credentials
Telecommunications engineer, Sales Support Manager at Newtec