A novel dual-band 90-degree coupler with harmonic suppression using open-ended stubs and spiral lines
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Saeed Gholami
Abstract
This paper presents the design and performance evaluation of a small-size dual-band 90° coupler optimized for operation at 2.42 GHz and 4.9 GHz, making it suitable for applications in 5G communication systems. The proposed coupler uniquely integrates open-ended stubs and spiral lines to achieve significant harmonic suppression, effectively eliminating unwanted harmonics up to the 7th order. This makes the design highly efficient for 5G bands, where minimizing interference and maintaining signal integrity are critical. The dual-band capability of the coupler is demonstrated with minimal insertion loss, with S21 parameters of 0.3 dB at 2.42 GHz and 0.8 dB at 4.9 GHz, and acceptable coupling S31 of 0.12 dB and 1.36 dB, respectively. The design also maintains a compact footprint, occupying an overall area of just 91.2 mm2 (
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Research ethics: Not applicable.
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Informed consent: Not applicable.
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Author contributions: All authors have 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 authors declare no conflict of interest.
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Research funding: This research received no external funding.
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Data availability: The corresponding author can be contacted on reasonable request.
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