Continue to Site

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.

Register Log in

AM, CW effect on Sensor (EMC)

Status
Not open for further replies.
H

harry456

Member level 1
Joined
Nov 13, 2012
Messages
39
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,286
Activity points
1,545
I read a paper in that is was mentioned that an CW with a peak of p=xdBm has the same effect on a ic than a modulated signal with peaks (all peaks have the same power as the cw signal). Is is possible? (the power of modulated signal would be much larger than that of the cw signal).
Would be nice if someone could post a source that proves this "thesis".
 

In EMC standards continues wave (CW) with 80% amplitude modulation (AM) is used. the average power of CW is zeros, so I think the AM is necessary.
 

If the sensor exhibits non linearity to RF, testing with CW, the result would be a shift in DC in the sensor, which may not effect subsequent amplifiers. if you use AM, then there will be the demodulated component as well as the DC shift, this would be a more stringent test.
Frank
 

"Same" I would say not. Reads the same on a peak level
meter or such, probably. Varying amplitude is going to
test response to low and high level, there may be more
to see than simple worst case input will expose.
 

What with FM modulation? How would FM modulation effect testing? (Is there a reason way it's not used? A FM spectrum is much broader than the spectrum of an AM - signal. Would I use a fm spectrum ( with more power than an AM-Signal so that all peaks in the spektrum are nearly of the same magnitude as the AM peaks could I not test the device faster than with an AM -Signal?)
 

The spectrum of a FM signal is relatively small compared with the potential frequencies that may interfer with the device. i.e. the spectrum of RF is 50 KHZ to 25 GHZ. the spectrum of a FM signal is typical limited to Fc +- 200KHZ.
Frank
 

Yes, it is. But you could use a fm signal with a bandwith of MHz and use it instead of an AM or CW Signal for the verification. Or is there a reason why it is not used? (it's not in the iso, but why not- wouldn't much faster?)
 

What is if i would like to replace the cw-test? A FM with a large modulation index looks similar to a rectangle (in the frequency-domain) could i not used it to test a sensor faster? (only for test purpouses not for emc-verification)
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top