A Novel Broadband Even-Mode Matching Network for Marchand Baluns

• Published in: IEEE transactions on microwave theory and techniques 2009-12, Vol.57 (12), p.2973-2980
• Main Authors: Chen, A.C., Anh-Vu Pham, Leoni, R.E.
• Format: Article
• Language: English
• Subjects: Applied sciences; Balancing; Baluns; Bandwidth; Broadband; Circuit properties; Electric, optical and optoelectronic circuits; Electronic circuits; Electronics; even mode; Exact sciences and technology; Impedance matching; Insertion loss; Inverters; isolation; Liquid crystal polymers; liquid-crystal polymer (LCP); Loss measurement; Marchand balun; Matching; matching network; microwave; Microwave circuits, microwave integrated circuits, microwave transmission lines, submillimeter wave circuits; Microwave devices; Microwaves; mixed-mode S -parameters; Networks; Noise levels; Phase measurement; Ports; Signal convertors; Stability
• ISSN: 0018-9480; 1557-9670
• DOI: 10.1109/TMTT.2009.2034220

In this paper, we present the development of an even-mode matching network for a Marchand balun to achieve 50-¿ match and high isolation at the balanced ports. A very wide matching bandwidth can be accomplished with the novel addition of an open-circuit stub to the network. Experimental results demonstrate that the even-mode matched balun achieves return losses that are greater than 15 dB at the balanced ports from 6 to 17 GHz. The measured isolation between the balanced ports is greater than 15 dB from 4 to 19 GHz. For the unbalanced port, the return loss is greater than 15 dB from 4 to 19 GHz. The measured insertion loss is less than 1 dB, and amplitude and phase imbalances are ±0.5 dB and ±5° from 4 to 18 GHz, respectively.