Texas Instruments TRF3703, User Manual, Page: 6 / 22

1.4 TRF3703 EVM Operating Procedure
1.4.1 Typical Test Results
1.4.1.1 Un-Optimized Sideband Suppression
Overview
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Set up the EVM as follows:
1. Power-supply connection:
a. Switch on the V
CC
(5-V) supply and set the current limit set to 235 mA.
b. Connect the 5-V supply to headers W1 and W2.
c. Verify that the current drawn is approximately
≤
205 mA for the TRF3703-15 and
≤
235 mA for the
TRF3703-33.
2. Use a suitable 50-
Ω
output signal generator (LO =
±
5 dBm) or the TRF3761 to supply the LO signal at
desired frequency to J1, and terminate J2 with 50
Ω
to ground.
3. Use a DAC or an arbitrary waveform generator to provide the I/Q input signals. A typical setup is as
follows: a 1-Vp-p sine wave, a frequency of 50 KHz, a dc-offset of 0 V, and an output impedance of
50
Ω
(typically an ESG vector signal generator or similar).
4. Set the common mode on the ESG to either 1.65 V or 0.75 V, depending on device type (set to 1.65 V
for the TRF3703-33, set to 0.75 V for the TRF3703-15).
5. Use an arbitrary waveform generator to suppress the sideband. Adjust the I/Q amplitude and phase of
the CW signal coming from the arbitrary waveform generator.
6. Connect a spectrum analyzer to the SMA connector marked RFOUT (J7) and monitor the TRF3703
output.
measures the amount by which the unwanted sideband of the input signal is attenuated in the output of
the modulator, relative to the wanted sideband. This assumes that the baseband inputs delivered to the
modulator input pins are perfectly matched in amplitude and are exactly 90
°
out of phase. Un-optimized
sideband suppression is measured in dBc. An iterative test is required in order to match perfectly the
inputs to the modulator. This ensures that any equipment, board, or signal conditioning component
imbalances are corrected before the signals are applied to the device under test. Once the baseband
inputs to the modulator are balanced, the amount of suppression attained is a measure of the internal
mismatches of the modulator, inherent to any modulator design. This suppression is the one specified in
the TRF3703 datasheet. See
Figure 1 .
6 TRF3703 Quadrature Modulator Evaluation Module SLWU042B – October 2006 – Revised August 2008
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