Texas Instruments TRF1500 - Manual (Page 55)

SWRA004A
56 TRF1500 Integrated Dual-Band RF Receiver User’s Guide
1) Set the TX source frequency and input power (see Table 5).
Connect the TX source to the EVM TX input port, J30.
2) Set the spectrum analyzer to measure at the TX frequency
(see Table 5).
3) Connect the LO In Port, J12, to the spectrum analyzer.
4) Measure the TX leakage power.
Low-Band Transmit Mixer: 1dB Input Compression Point
Control state: 010100
SEE APPENDIX A: TEST BENCH SETUPS
Test setup Figure 20
The 1 dB input compression point is the TX RF input power at
which the gain compresses 1 dB. Gain compression is when an
increase in P
in
causes no further increase in the output power
(P
out
). The measurement is performed using two RF sources and a
spectrum analyzer.
1) Set the TX RF source frequency (see Table 5) and the input
power (P
in
) to -35 dBm. Connect the RF source to the EVM RF
input port, J30.
2) Set the LO source frequency and input power (see Table 5).
Connect the LO source to the EVM LO input port, J12.
3) Set the spectrum analyzer to measure the output power at the
IF frequency.
4) Connect The EVM TX IF output port, J31, to the spectrum
analyzer.
5) Measure the output power (P
out
) at the IF frequency
6) To determine the 1 dB compression point, the TX RF P
in
is
increased in steps of 1 dBm until the gain compresses by 1
dB. Repeat step 4 and 5 until the gain compresses by 1dB.
7) Calculate Gain as:
Gain = P
out
- P
in
RF P
in
P
out
Gain
-35 -16 19
-34 -15 19
-33 -14 19
-32 -13 19