Adopting the broadside coupled line for the design of an impedance transformer

Summary form only given, as follows. A compact impedance transformer with a broadside coupled line is provided in this paper. With the assistant of the proposed broadside coupled line, the electrical length of the impedance transformer would be smaller than a quarter wavelength. In addition, analytic equations for the design of complex impedance transformer are derived; the optimal characteristic impedance and transformation ratio for successful power transfer are calculated as well.