IIP3 measurement_two tone analysis

[vivek1214]

hello friens,
I am working on bluetooth front end design. I want to measure IIP3 by two tone method. Bluetooth frequency range is 2.40GHz to 2.48GHz.
Which two tone I should take for linearity(IIP3) analysis.

 

[khouly]

the 3rd order intercept point (2F1-F2) this should produce a frequency close to the RF signal
so select channel and calculate the 2F1-F2 = Fchannel

khouly

 

[vivek1214]

but after amplifier there are two downconversion stages. so what should i take?

 

[khouly]

take care , the produced signal will be down converter to the IF
by the 2 stages , so u can use tones normaly

khouly

 

[Element_115]

Just use 2.42GHz &2.43GHz for the low side. Use 2.46GHz and 2.47GHz for the
high side of the band. And you can do more if you like, just to characterizer
your whole channel.

Having access to the output is what might be difficult and you will have to
figure that out. It might not be worth it to do an IIP3measurement.
You can always do a BER and extrapolate a rough IP3 value.

 

[vivek1214]

i am simulating front end for center freg 2.44ghz ,lo1=2.24ghz , lo2= 198mhz, in that case what should be my tones for IIP3 measurement. and in HB simulator what frequency i should mention?

 

[vfone]

From section 4.4 of the Bluetooth specification, the reference sensitivity performance, BER = 0.1%, shall be met under the following conditions:
- The wanted signal at frequency fo with a power level 6 dB over the reference sensitivity level (-85dBm + 6dB = -79dBm).
- A static sine wave signal at f1 with a power level of –39 dBm
- A Bluetooth modulated signal at f2 with a power level of -39 dBm. Such that fo =2f1 -f2 and |f2 -f1|=n*1 MHz where n can be 3, 4, or 5. The system must fulfill one of the three alternatives