Four decade bandwidth uniplanar balun

A new realisation of a double junction balun with four decade bandwidth is presented. The balun is designed using coplanar line (CPS) and coplanar waveguide with finite ground planes (CPWFGP). The simple theoretical model which describes the double junction balun as the all-pass network has been introduced. The measured VSWR is less than 1.3 and insertion loss less than 0.5 dB in the frequency range 300 kHz–4.0 GHz.