Low-band cascaded: noise figure – Texas Instruments TRF1500 User Manual

Page 27

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SWRA004A

28

TRF1500 Integrated Dual-Band RF Receiver User’s Guide

4) Connect the EVM IF output port, J11, to the spectrum

analyzer.

5) Measure the output power at the IF frequency (IF P

out

) with the

spectrum analyzer.

6) Enable the strong signal. Measure the output power at the IF

frequency (SS IF P

out

) with the spectrum analyzer.

7) Calculate Power conversion gain reduction as:

Power Conversion Gain Reduction = (IF P

out

- SS IF P

out

).

Low-Band Cascaded: Noise Figure

Control state: 011000

SEE APPENDIX A: TEST BENCH SETUPS

Test setup Figure 22

The cascaded Noise Figure (NF) is measured at the EVM Low
Band IF output port, J11. The measurement is performed using an
HP8970B Noise Figure Meter. The IF output of the mixer is
converted from differential to single ended using a transformer
balun. The noise figure meter requires a special setup and
calibration since the RF source and receive frequencies are
different.

Set up the noise figure meter as follows:

1) Special Function 1.4 sets the noise figure meter to measure

variable IF and fixed LO frequencies.

2) The IF start, stop, and step size frequencies are set to

100MHz, 120MHz, and 5MHz respectively.

3) Set the smoothing to 16 or above.

4) Ensure that the Excess Noise Ratio (ENR) Table on the Noise

Source head in use is entered on the NF meter.

a) On the front panel, press the ENR button.

b) Check the ENR value by pressing the Enter button or enter

the ENR value for each frequency.

c) After entering the ENR for the desired frequency, press the

Frequency button on the front panel to exit.

5) To calibrate the NF Meter:

a) Connect the Noise Source directly to the NF meter; press

the calibration twice

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