A Compact Hybrid Branch Line Coupler at 2.68 GHz

The paper represents the compact hybrid backward wave branch line coupler resonating at 2.68GHz suitable for various applications due to the relatively wide bandwidth (2.14-2.95GHz).The proposed design is simulated utilizing Sonnet Suites Software and the simulated results are in close match with the measured data obtained after the fabrication of the coupler. Furthermore, the S parameters of both simulated and measured results are in the acceptable range. The input match and isolation factor are approximately -30.31dB, whereas coupling factor and insertion loss are around -3.01dB respectively. In addition, the FR-4 dielectric substrate (er = 4.4) with the thickness of 1.55mm is used for the proposed design despite the tangent losses of the FR-4 substrate. The given design is somewhat inexpensive, having a very simple geometry and reliable with a wide bandwidth, it can be used in numerous microwave technological applications.