120
Views
3
CrossRef citations to date
0
Altmetric
Articles

High CM suppression balanced broadband BPF with hybrid hairpin-interdigital structure

, , , &
Pages 2379-2389 | Received 02 May 2013, Accepted 29 Sep 2013, Published online: 18 Oct 2013
 

Abstract

A compact, high selectivity and good common-mode (CM) suppression balanced broadband bandpass filter (BPF) is proposed using hybrid hairpin-interdigital structure. Under the differential-mode (DM) excitation, the filtering topology is formed by n + 1 quarter-wavelength resonators (QWRs) and n hairpin resonators (HRs) instead of QWRs with coupled-line I/O coupling structure. But, the DM circuit still maintains high selectivity and broadband characteristics of the interdigital BPF. By reasonably choosing the coupling length and the length of the HR, the balanced BPF can not only obtain the desired DM frequency response, but the CM harmonic generated by the HR can be well suppressed by the CM transmission zero created by the coupling between the HR and half-wavelength resonator (HWR). No via-hole ground for the balanced broadband BPF is required, reducing the implementation complexity. Finally, the third-, fifth-, and seventh-order balanced broadband BPF prototypes are designed and fabricated, and the simulated and measured results show a good agreement. The CM signal for seventh-order case has been suppressed below −46.5 dB in the whole DM frequency band.

Acknowledgment

This work was supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD).

Reprints and Corporate Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

To request a reprint or corporate permissions for this article, please click on the relevant link below:

Academic Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

Obtain permissions instantly via Rightslink by clicking on the button below:

If you are unable to obtain permissions via Rightslink, please complete and submit this Permissions form. For more information, please visit our Permissions help page.