This application note shows the typical impedance values for small loops and suggests matching networks for these impedances. It

demonstrates the effectiveness of these networks in suppressing harmonics of the transmitted frequency. Most transmitter ICs that

serve these applications, like the Maxim MAX7044, MAX1472, and MAX1479, are biased for maximum efficiency rather than maximum

linearity, which means that the harmonic content of the power amplifier (PA) output may be very high. Regulatory agencies in all

countries where these devices are used restrict spurious emissions, so attenuating harmonic power from the PA is very important.