Design of a Microstrip Out-of-Phase Power Divider Using Shorted-Coupled-Line Transformer

This paper presents a new equal split power divider with out of phase signals between two output ports. The divider comprises two transmission line sections, one resistor, one capacitor, one short stub, one shorted-coupled-line (SCL) transformer, and one quarter-wavelength (lambda/4) transformer. The SCL transformer plays three crucial roles. The first and second roles are to improve selectivity of vertical bar S-21 vertical bar and isolation of out-of band, respectively. The third role is to produce 270 degrees phase difference. Thus, the phase difference between SCL and lambda/4 transformers can achieve 180 degrees requirement.