Balanced dual-band BPF with enhanced DM selectivity and stopband suppression
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Ming Hua Liu
Abstract
In this paper, a balanced dual-band bandpass filter (BPF) with enhanced differential-mode (DM) selectivity and stopband suppression is proposed. The design utilizes four half-wavelength stepped impedance resonators (SIRs) with mixed electromagnetic couplings to generate two DM passbands at 2.47 GHz and 3.53 GHz. By optimizing resonator dimensions (Lr4, Lr13) and coupling gaps (g1, g2), the center frequencies and fractional bandwidths (FBWs) of both passbands are independently controlled. A U-type transition structure enables intrinsic common-mode (CM) suppression exceeding 42 dB, while source-load coupling introduces four transmission zeros (TZs) to sharpen DM selectivity. Measured results show insertion losses (ILs) of 1.72 dB and 1.70 dB, return losses >17 dB, and a wide out-of-band suppression up to 6.7 GHz. The design outperforms the existing works in TZ count and flexibility, validated through rigorous simulation and measurement.
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Research ethics: Not applicable.
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Informed consent: Not applicable.
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Author contributions: The author has accepted responsibility for the entire content of this manuscript and approved its submission.
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Use of Large Language Models, AI and Machine Learning Tools: None declared.
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Conflict of interest: The author states no conflict of interest.
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Research funding: None declared.
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Data availability: Not applicable.
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Articles in the same Issue
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- A review on soft computing optimization techniques for electromagnetics
- Editorial
- Design of wideband filtering phase shifters with wide stopband
- Research Articles
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Articles in the same Issue
- Frontmatter
- Review Articles
- Advances in antenna design through characteristic modes: a review of simulation techniques and development
- A review on soft computing optimization techniques for electromagnetics
- Editorial
- Design of wideband filtering phase shifters with wide stopband
- Research Articles
- Balanced BPFs with wideband CM suppression and high selectivity based on double-sided parallel-strip line
- Balanced dual-band BPF with enhanced DM selectivity and stopband suppression
- Balanced dual-wideband BPF utilizing quad-mode slotline resonator
- Design, fabrication and testing of microwave bandpass filter using metamaterial integrated rectangular waveguide
- High-gain UWB Fabry–Perot cavity antenna with dual-notched band for high-resolution imaging applications
- A four port MIMO antenna using chip resistor based decoupling in 5G and 6G applications
- Contactless early-stage deep seated breast tumor detection using circular slotted patch antenna
- An ultraminiaturized implantable antenna with low SAR for biotelemetry
