To obtain Zopt, a load-pull analysis is typically conducted using an impedance tuner and network analyzer, referenced to the PA output pad (RFO) of SX1261/2. During this process, the load presented to the PA output is swept in magnitude and phase while recording the output power and current consumption. The results are then plotted on a Smith chart in the Figure 16, the highest output power of 14.6 dBm at 915 MHz was identified to be at an impedance of 11.7 + j4.8 ohms, while 13.5 + j7.6 ohms offers lower output power but with higher efficiency.