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.

Cascade IP3 Calculation

Status
Not open for further replies.

ruwan2

Member level 5
Member level 5
Joined
Nov 29, 2011
Messages
90
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,286
Activity points
2,141
Hi,
I read the following link on IP3 calculation:
**broken link removed**

There are three stages (stage 1 and stage 3 are amp while stage 2 is bandpass filter) which has the OIP3 and gain respectively:
OIP3 +21dBm(125.9) inf dBm(inf) +25 dBm(316.2)
Gain 15 dB (31.62) -3 dB (.5) 15 dB (31.62)

After calculate cascading OIP3, it gives:
OIP3 = 273.075 = 24.4 dBm , IIP3 = 24.4 - 33 = -8.6 dBm

Where does the 33 come from?
Could you help me on that?
Thanks,
 

Hi,
I read the following link on IP3 calculation:
**broken link removed**

There are three stages (stage 1 and stage 3 are amp while stage 2 is bandpass filter) which has the OIP3 and gain respectively:
OIP3 +21dBm(125.9) inf dBm(inf) +25 dBm(316.2)
Gain 15 dB (31.62) -3 dB (.5) 15 dB (31.62)

After calculate cascading OIP3, it gives:
OIP3 = 273.075 = 24.4 dBm , IIP3 = 24.4 - 33 = -8.6 dBm

Where does the 33 come from?
Could you help me on that?
Thanks,

The 33 is due to the fact that they went from OIP3 to IIP3. The difference of IIP to OIP is the Gain.
So if you subtract the Gains from the system and take it away from the OIP3 you will get the IIP.
But it should be 27dB not 33. --> 15+ (-3) +15 = 27
 
  • Like
Reactions: ruwan2

    ruwan2

    Points: 2
    Helpful Answer Positive Rating
Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top