Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

How to measure VNA Noise Floor?

Wingmaker101

Newbie
Joined
Feb 5, 2021
Messages
3
Helped
0
Reputation
0
Reaction score
0
Trophy points
1
Activity points
22
Hello, every VNA sold has noise floor specifications in their datasheet. Noise floor level is used to calculate its dynamic range.

So anyone know the right method to measure VNA noise floor?
 

Wingmaker101

Newbie
Joined
Feb 5, 2021
Messages
3
Helped
0
Reputation
0
Reaction score
0
Trophy points
1
Activity points
22
Thanks, the paper documents how noise floor is defined, and ways to reduce noise floor level thus improving dynamic range.

Does anyone know exactly how to measure it on VNA screen? For example, do we measure S11 when measuring noise floor of VNA Port 1? Do we turn off the RF power, etc?
 

vfone

Advanced Member level 5
Joined
Oct 10, 2001
Messages
5,313
Helped
1,550
Reputation
3,103
Reaction score
1,161
Trophy points
1,393
Activity points
33,666
A quick check would be to calibrate the VNA, and after this, put the 50 ohms load from the cal-kit on port 1, and do a scalar S11 measurement.
The S11 indication is the noise floor of the VNA for a specific frequency. The test includes the measurement bandwidth.
As the document posted above mention, the noise floor of the VNA can be reduced by increasing averaging and BW reduction.
 

biff44

Advanced Member level 5
Joined
Dec 24, 2004
Messages
4,926
Helped
1,363
Reputation
2,722
Reaction score
1,041
Trophy points
1,393
Location
New England, USA
Activity points
37,026
if it were me, i would get something like a 70 dB step attenuator, leave the IF bandwidth high, and start clicking in 10 dB steps. when the measured S21 magnitude departs significantly from the step attenuator reading, i would say i hit the noise floor.
 

Wingmaker101

Newbie
Joined
Feb 5, 2021
Messages
3
Helped
0
Reputation
0
Reaction score
0
Trophy points
1
Activity points
22
A quick check would be to calibrate the VNA, and after this, put the 50 ohms load from the cal-kit on port 1, and do a scalar S11 measurement.
The S11 indication is the noise floor of the VNA for a specific frequency. The test includes the measurement bandwidth.
As the document posted above mention, the noise floor of the VNA can be reduced by increasing averaging and BW reduction.
If we measure S11, it is in dB, a ratio measurement. How do we quantify the noise floor level in dBm though?
 

LaTeX Commands Quick-Menu:

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top