PROJECT TITLE :

Compact coupled-line balun with complex impedances transformation and high isolation

ABSTRACT:

A planar microstrip circuit is proposed to design a quite coupled-line balun with smart ports matching and high output-ports isolation for complex source to complicated load impedance transformation. This balun prototype essentially consists of three coupled-line sections, a tapped open transmission-line stub (TOTS) on the left-hand facet, and a tapped complicated equivalent-impedance half (TCEP) on the right-hand aspect. The TCEP is that the key to grasp high output isolation and all ports matching. Based mostly on the traditional even-odd mode technique and also the transmission-line theory, closed-form mathematical equations for circuit electrical parameters are obtained. To demonstrate this proposed style theory, a practical microstrip coupled-line balun is designed, simulated and measured to control at approximately a pair of GHz, indicating high isolation and balanced output. Smart agreements between the simulated and measured results verify this design.