Texas Instruments TRF1500 manual High-BandCascaded 1dB Input Compression Point

Models: TRF1500

1 74
Download 74 pages 41.68 Kb
Page 46
Image 46
High-Band Cascaded: 1dB Input Compression Point

SWRA004A

6)Connect the EVM IF output port, J21 to the spectrum analyzer.

7)Measure the Fundamental output power at the IF frequency (FFund).

8)Measure the Intermodulation products (2F2 - F1 or 2F1 - F2) at FIF ± 120 kHz

9)Calculate the Intermodulation Suppression as:

Intermodulation Suppression = FFund - Intermodulation product

10) Calculate the Input Third -Order Intercept Point as:

Input Third-Order Intercept = ((Intermodulation

Suppression/2) + (RF Pin))

High-Band Cascaded: 1dB Input Compression Point

Control state: 111001

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 Pin causes no further increase in the output power (Pout). The measurement is performed using two RF sources and a spectrum analyzer.

1)Set the RF source frequency (see Table 4) and the input power (Pin) to -35 dBm. Connect the RF source to the EVM RF input port, J20.

2)Set the LO source frequency and input power (see Table 4). 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, J21, to the spectrum analyzer.

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

6)Calculate Gain as:

Gain = Pout - Pin

7)To determine the 1 dB compression point, the RF Pin 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.

TRF1500 Integrated Dual-Band RF Receiver User’s Guide

47

Page 46
Image 46
Texas Instruments TRF1500 manual High-BandCascaded 1dB Input Compression Point