MINIATURIZATION OF BRANCH-LINE COUPLERS USING OPEN STUBS AND STEPPED IMPEDANCE UNIT CELLS WITH MEANDERING TRANSMISSION LINES
S. Elkorany. Circuits and Systems: An International Journal (CSIJ)1 (3):
In this paper, two proposed structures of the compact Branch-Line Couplers BLCs are designed and simulated. Three different technologies of miniaturization BLC are used together, open ended stubs, meandering transmission lines, and stepped impedance. The results of the two designed BLC are compared to previously published results work at the same frequency 1.8GHz, the two proposed structures are designed and simulated using CST full wave simulator. The first and second structures are occupied only 61.8% and 50.8%, respectively, from the area of the conventional design. The paper presents a comparative study between simulated results of the two proposed designs and the measured results, the results show good agreement especially in the stepped impedance BLC.