Design of a Marchand Balun

This work describes a design of a printed Marchand balun from the perspective of its cavity counterpart. The cavity balun is first planarized and then folded to accommodate into a spiral antenna. The width of the proposed balun is reduced to alleviate the influence to the spiral radiator. A simple planar structure based on a one-layered microstrip substrate is exploited to realize the design of the circuit scheme. It may reduce the degree of difficulty of Marchand balun working in very high frequency domain and enhance the rate of en-products by PCB technology. Finally, experimental results of the designed balun integrated with a spiral antenna working from 0.8 GHz to 5 GHz are provided to demonstrate the appealing performance of the design.