Wide-band reduced-size uniplanar magic-T, hybrid-ring, and de Ronde's CPW-slot couplers

New reduced-size uniplanar magic-T and hybrid-ring coupler suitable for MIC's and MMIC's have been developed using a CPW-slotline ring that is 20% smaller than comparable designs. These circuits provide good amplitude and phase characteristics over a broad bandwidth. Experimental results show that the hybrid-ring coupler has a 1.3 octave bandwidth centered at 4 GHz and the magic-T has a bandwidth of 1.6 octave from 2-6 GHz. Both have a maximum power dividing imbalance of 0.4 dB and a 2.5 degrees maximum phase imbalance. Also a new uniplanar de Ronde's CPW-slot directional coupler was developed with good performance. The even-odd mode analysis of four-port networks with double symmetry was used to analyze this coupler. A de Ronde's coupler with 5 dB coupling was designed and demonstrated over the frequency range of 2.4-3.4 GHz. The measurement results agree with the theoretical design.