Texas Instruments TRF1500 - Manual (Page 63)

SWRA004A
64 TRF1500 Integrated Dual-Band RF Receiver User’s Guide
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 products are equal. The
measurement is performed using two RF sources and a spectrum
analyzer.
1) Set the first RF source input power (RF P
in
) and frequency
(F1) (see Table 7).
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, J10.
4) Set the spectrum analyzer to measure at the RF frequency
(F1 ) (see Table 7).
5) Connect the EVM IF output port, J11 to the spectrum analyzer.
6) Measure the Fundamental output power at the RF frequency
(F
Fund
).
7) Measure the Intermodulation products (2F
2
- F
1
or 2F
1
- F
2
) at
F
IF
±
60 kHz
8) Calculate the Intermodulation Suppression as:
Intermodulation Suppression = F
Fund
- Intermodulation
product
9) Calculate the Input Third -Order Intercept Point as:
Input Third-Order Intercept = ((Intermodulation
Suppression/2) + (RF P
in
))