Measure IIP3 of Device Under Test

Use the IIP3 Testbench block to measure the input third-order intercept (IIP3) of device under test (DUT).

Connect the blocks as shown in the model.

Set the parameters for DUT and the testbench.

Amplifier block:

• Available power gain — 10 dB

• Intercept points convention — Input

• IP3 — 32 dBm

Mixer block:

• Available power gain — 5 dB

• Local oscillator frequency — 2.0 GHz

• Add Image Reject filter — on

• Intercept points convention — Input

• IP3 — 35 dBm

• Filter type — Highpass

• Implementation — Constant per carrier

• Passband edge frequency — 2.0 GHz

IIP3 Testbench block:

• Input frequency (Hz) — 2.1e9

• Output frequency (Hz) — 0.1e9

• Simulate noise (both stimulus and DUT internal) — off

Run the model. You will see that the display shows an IIP3 value of 24.19 dBm. This value can be verified analytically using the equation provided in [1].

IIP3 of the DUT = – 10*log10(1/10^((32)/10) + 10^(10/10)/10^((35)/10)) = 24.2099 dBm

where,

IIP3 of the amplifier in linear scale = 10^((32)/10)

IIP3 of the mixer in linear scale = 10^((35)/10)

Available power gain of the amplifier = 10^(10/10)

References

[1] Razavi, Behzad. “Basic Concepts “ in RF Microelectronics, 2nd edition, Prentice Hall, 2012.