Circuit model for coplanar-slotline tees

Coplanar-slotline tees have been used in a number of microwave circuits, although no complete models were available to explain their behavior. In this letter, a new "circuit-model" for a coplanar-slotline tee is presented. The model, based on the separation of coplanar waveguide (CPW) even and odd modes into two different ports, explains the tee's behavior even if CPW air bridges are not used and slotlines are loaded asymmetrically. The new model has been applied to the analysis of the input reflection coefficient of an offset-fed slotline antenna, showing an excellent agreement between simulation and measurement.

[1]  C. Nguyen,et al.  Uniplanar broad-band push-pull FET amplifiers , 1997 .

[2]  A. Nesic,et al.  Endfire slotline antennas excited by a coplanar waveguide , 1991, Antennas and Propagation Society Symposium 1991 Digest.

[3]  T. Mader,et al.  Quasi-optical antenna array amplifiers , 1995, Proceedings of 1995 IEEE MTT-S International Microwave Symposium.

[4]  Tatsuo Itoh,et al.  The effects of the coupled slotline mode and air-bridges on CPW and NLC waveguide discontinuities , 1995 .

[5]  G.M. Rebeiz,et al.  Single- and dual-polarized slot-ring subharmonic receivers , 1997, 1997 IEEE MTT-S International Microwave Symposium Digest.