Design of a Compact Hybrid Branch Line Coupler with 2-D Implementation of Stepped Impedance Transmission Lines of High Impedance Ratio for Wide Range of Harmonic Suppression

摘要

In this paper stepped impedance transmission line (TL) structure is adopted by using proposed unorthodox technique to design a hybrid branch line coupler (HBLC) in micro-strip technology. In addition to achieving good fractional bandwidth of 30% and size reduction of 56%, the proposed technique ensures a high impedance ratio (M) over a wide range of electrical lengths of the high-Z low-Z (stepped impedance) sections. Maintaining high M ensures a good harmonic suppression of the proposed design up to 9f(0) (f(0) is the design frequency which is 1GHz for this work). Experimental verification of the proposed technique is demonstrated by designing an HBLC at 1GHz. Experimental and simulation results show excellent conformance.