How to measure IP3 and Blocking Dynamic Range of HF transceiver

Hi all,
I have a HF transceiver (Input RF signal, Output audio signal). Please help me how to measure IP3 and Blocking Dynamic Range!?
Thanks in advance

Try section 5.7 & 5.8 of
http://tinyurl.com/testproc2011

A search for "receiver blocking range measurement" gives plenty of references

when i increase or decrease input signal power, IM3 was changed.
How can I find optimize input signal power to measure accurately IP3?

Here is a pretty good explanation of IMD and how to measure it.

http://users.tpg.com.au/users/ldbutl...modulation.htm

If the input power is close to the compression point of the receiver, IM3 will change with input power.
As a basic rule for accurate IM3 measurements, the combined power of the two-tones should be at least 10dB below the compression point of the receiver.

Because you are measuring non linearity, where you measure will certainly alter the result. IP3 is not, and can never be measured directly.

Its a two step process. First you measure the input amplitude of two input test signals where they just become visible above the noise floor (say noise +3db).
That gives you your minimum input threshold sensitivity.

Then you keep increasing the input amplitude until the third order products also start to appear either side of the two test signals above the noise floor. (also noise +3db).

That tells you the dynamic range of linear operation where no significant third order products above the noise floor are created.
From that you calculate the theoretical fictional point where the third order products would be equal in amplitude to the test signal amplitude.

Its rather like measuring how high a pyramid is by making some measurements near ground level and calculating the height.

The calculated IP3 input level should be very high, much higher than any practical signal you could ever force through your receiver. It will clip long before it ever reaches theoretical IP3 input levels.

What you want is for the receiver to be as linear as possible over as wide a dynamic range as possible. Because linearity problems always follow an unefinable curve, IP3 is a calculated figure of merit that is used as a comparative measurement.