... isolation between ports 1 and 4, and 2 and 3 is greater than 19 dB in the 3.1 to 10.6 GHz frequency band. In the same band, the coupling between ports 1 and 3 and 2 and 4 is 3 dB with a ±1 dB ... the reference to Port 1 and 2 Advanced Microwave Circuits and Systems3 54 The simulated magnitudes of q4, q5, q6 and q7 are 2.3 ± 0.9, 1.9 ± 0.8, 2.1 ± 0.6 and 2.5 ± 0.9, while the ... IEEE Transactions on Microwave Theory and Techniques, Vol. 23, No. 12, December 1975, pp. 978–984, ISSN. 0018-9480. Advanced Microwave Circuits and Systems3 70where Z0 and Z1are impedances...