Design and Development of Coaxial Line Based 2kW, 10-30dB Variable Dual Directional Coupler

Design and development of the 2kW coaxial line based 10-30dB and 10-500MHz variable loop type dual directional coupler has been presented. The developed coupler consists of a main coaxial transmission line with two similar movable loop type coupling arrangements. The movable loops provide variable coupling magnitudes. Using these two arrangements forward and reflected power can sampled out at different coupling magnitude as per desired. The developed coupler has been tested and found providing return loss better than -10dB, isolation better than - 25dB whereas coupling is range -10 dB to -30dB in frequency range of 10 to 500 MHz.