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.

Frequency location of the two-tone testing

Status
Not open for further replies.

neo

Member level 2
Joined
Aug 19, 2004
Messages
51
Helped
1
Reputation
2
Reaction score
1
Trophy points
1,288
Location
Beijing
Activity points
450
I do remember i've seen a topic discussing about how to locate the two frequency in the two-tone method for IIP3 testing. but i cannot find it now, anybody can help explain it again? e.g. choose f1=flo-100M, f2=flo-195M, and the IM3 tone 8M after the mixer. i really want to know why and how we choose the frequency apart of the two tone.
 

biff44

Advanced Member level 5
Joined
Dec 24, 2004
Messages
4,981
Helped
1,372
Reputation
2,740
Reaction score
1,042
Trophy points
1,393
Location
New England, USA
Activity points
37,501
Well, you certainly can have diffierent results at different frequency spacings. You want to look at your modulation scheme and figure out what is appropriate. If you have a lot of envelope peaking with low frequency modulation, like voice, you obviously want the tones spaced close together (a few KHz) to see if your amplifier's bypass capacitors are adequate. If you have a lot of channels, line in a cable TV application, you want to guess which tones would give you the most trouble, in fact sometimes even to the point of doing a 5-tone test, spaced at your channel frequencies, to try to stress the amplifiers the most. In other words, the test should emulate how you are going to use the component.
 

neo

Member level 2
Joined
Aug 19, 2004
Messages
51
Helped
1
Reputation
2
Reaction score
1
Trophy points
1,288
Location
Beijing
Activity points
450
i got ur point that "try to stress the amplifiers the most", but i am confusing about the "spaced at your channel frequencies", should i consider the multi tones spaced at different channels or, multi tones in a channel?
 

vfone

Advanced Member level 5
Joined
Oct 10, 2001
Messages
5,447
Helped
1,572
Reputation
3,147
Reaction score
1,180
Trophy points
1,393
Activity points
34,598
**broken link removed**
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top