Texas Instruments TRF1500 - Manual (Page 57)

SWRA004A
58 TRF1500 Integrated Dual-Band RF Receiver User’s Guide
Low-Band Transmit Mixer: Third Order Input Intercept Point
(IIP3)
Control state: 010100
SEE APPENDIX A: TEST BENCH SETUPS
Test setup Figure 21
The third order input intercept point is the level of the RF input
power at which the output power levels of the undesired
intermodulation products and the desired IF products are equal.
The measurement is performed using three RF sources and a
spectrum analyzer.
1) Set the first RF source input power (RF P
in
) and frequency
(F1) (see Table 5).
2) Set the second RF source frequency to the first RF frequency
plus 60kHz; F
2
.
3) Using a RF combiner, connect the RF sources to the EVM RF
input port, J30.
4) Set the LO source frequency and input power (see Table 5).
Connect the LO source to the EVM LO input port, J12.
5) Set the spectrum analyzer to measure at the IF frequency (F
IF )
(see Table 5).
6) Connect the EVM IF output port, J31 to the spectrum analyzer.
7) Measure the Fundamental output power at the IF frequency
(F
Fund
).
8) Measure the Intermodulation products (2F
2
- F
1
or 2F
1
- F
2
) at
F
IF
±
60 kHz
9) Calculate the Intermodulation Suppression as:
Intermodulation Suppression = F
Fund
- Intermodulation
product
10) Calculate the Input Third -Order Intercept Point as:
Input Third-Order Intercept = ((Intermodulation
Suppression/2) + (RF P
in
))