Texas Instruments TRF1500 - Manual (Page 32)

SWRA004A
TRF1500 Integrated Dual-Band RF Receiver User’s Guide 33
Low-Band Cascaded: 1dB RF Input Compression Point
Control state: 011000
SEE APPENDIX A: TEST BENCH SETUPS
Test setup Figure 20
The 1 dB input compression point is the 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 RF source frequency (see Table 3) and the input
power (P
in
) to -35 dBm. Connect the RF source to the EVM RF
input port, J10.
2) Set the LO source frequency and input power (see Table 3).
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 IF output port, J11, to the spectrum
analyzer.
5) Measure the output power (P
out
) at the IF frequency
6) Calculate Gain as:
Gain = P
out
- P
in
7) To determine the 1 dB compression point, the 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.
RF P
in
P
out
Gain
-35 -10 25
-34 -9 25
-33 -8 25
-32 -7 25
-31 -6 25
-30 -5 25
-29 -4 25
-28 -3 25
-27 -2 25
-26 -1.2 24.8
-25 -0.4 24.6