SWRA004A

3)Set the spectrum analyzer to measure at the IF frequency (see Table 5).

4)Connect the EVM IF output port, J31, to the spectrum analyzer.

5)Measure the IF output power (IF Pout) at the IF frequency with the spectrum analyzer.

6)Calculate the Cascaded Gain as:

Gain = (IF Pout - RF Pin) + Transformer Loss. The transformer loss is 1.8dB.

Low-Band Transmit Mixer: Noise Figure

Control state: 010100

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, J31. 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 114MHz, 120MHz, and 3MHz 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 button twice.

TRF1500 Integrated Dual-Band RF Receiver User’s Guide

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Image 52
Texas Instruments TRF1500 manual Low-Band Transmit Mixer Noise Figure