Single- and Dual-Band Power Dividers Integrated With Bandpass Filters

• Published in: IEEE transactions on microwave theory and techniques 2013-01, Vol.61 (1), p.69-76
• Main Authors: Li, Yuan Chun, Xue, Quan, Zhang, Xiu Yin
• Format: Article
• Language: English
• Subjects: Applied sciences; Band pass filters; Bandpass filter (BPF); Circuit properties; Dual band; Electric, optical and optoelectronic circuits; Electronic circuits; Electronic equipment and fabrication. Passive components, printed wiring boards, connectics; Electronics; even- and odd-mode; Exact sciences and technology; Frequency filters; Impedance; Microwave circuits, microwave integrated circuits, microwave transmission lines, submillimeter wave circuits; Passband; power divider; Power dividers; Power transmission lines
• ISSN: 0018-9480; 1557-9670
• DOI: 10.1109/TMTT.2012.2226600

This paper presents a novel device integrating a power divider with two bandpass filters. It is capable of splitting power and selecting frequency at the same time. The phase shift of the filter is found to be ±90° at the center frequency. Therefore, when it is matched to 70.7 Ω, it can replace the conventional quarter-wave length transmission line in the power divider. The isolation elements are loaded at the filters' open ends to get a good isolation between the output ports. As a result, both the transmission and isolation property are satisfied. The equivalent even- and odd-mode circuits of the proposed structure are analyzed and design equations are derived. They are used to guide the design of the devices. For demonstration, filter-integrated power dividers with single- and dual-band operation are implemented, respectively. Comparisons of the measured and simulated results are presented to verify the theoretical predications.