Use the following guidelines for S-parameter measurement:
- As Figure 4-1 shows, the S-parameter measurement is typically done using a Vector Network Analyzer (VNA). For measuring the TRF1108 EVM, a 3-port VNA is recommended which can generate differential and receive single-ended signals at the input and output ports of EVM respectively.
- Before connecting the RF coax cables to the EVM, you must calibrate the VNA along with the cables using a calibration kit.
- Make sure the frequency sweep and output power level from the VNA is set within the linear operating range of the TRF1108 devices. The resolution bandwidth (RBW) and dynamic range of the VNA can be adjusted to give optimum sweep time for the measurement.
- Account for board trace losses at the input and output side of the device during gain measurements. Figure 4-2 gives typical input and output trace losses measured on the EVM.