Texas Instruments TRF1500 - Manual (Page 68)

SWRA004A
TRF1500 Integrated Dual-Band RF Receiver User’s Guide 69
J12, may be necessary to eliminate the broad band noise
during testing.
9) Connect the EVM IF output port, J11, to the noise figure meter
input port.
a) A bandpass or low pass filter may be necessary on the IF
port to eliminate the LO signal interference and get an
accurate noise measurement.
10) Measure the Noise Figure.
Low-Band Receiver Mixer: 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 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 Mixer RF source frequency (see Table 8) and the input
power (P
in
) to -35 dBm. Connect the RF source to the EVM RF
input port, J15.
2) Set the LO source frequency and input power (see Table 8).
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 Mixer 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 mixer 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
-25 -15 10
-24 -14 10