A wideband 10 dB hybrid ring

An enhanced-bandwidth 10 dB hybrid ring is proposed in this paper. A novel composite microstrip model of a phase-reversing short circuit coupling line with defected ground structure (DGS) is also proposed, and the related parameters of the circuit are given. Compared to the conventional transmission line, the novel structure has the characteristic of an advanced phase shift. Besides, it is also characterized by small, compact and easily realized size. Based on this, an X-band (8-12 GHz) 1:10 hybrid ring is proposed. The simulated and measured results show that the hybrid ring has perfect amplitude and phase characters.