
- This is the simplest voltage balun, consisting of two coils of wire connected as shown
- The coils may use an air core or a ferrite core
- Current flowing through the lower coil induces an equal and opposite voltage in the upper coil
- The primary circuit contains N turns and the secondary 2N, so the input impedance is
- ZL(N ÷ 2N)2 = ¼ ZL