Low-loss frequency-agile bandpass filters with controllable bandwidth and suppressed second harmonic
Research output: Journal Publications and Reviews › RGC 21 - Publication in refereed journal › peer-review
Author(s)
Related Research Unit(s)
Detail(s)
Original language | English |
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Article number | 5463054 |
Pages (from-to) | 1557-1564 |
Journal / Publication | IEEE Transactions on Microwave Theory and Techniques |
Volume | 58 |
Issue number | 6 |
Publication status | Published - Jun 2010 |
Link(s)
Abstract
This paper presents a novel approach to design frequency-agile bandpass filters with constant absolute bandwidth and passband shape, as well as a suppressed second harmonic. A novel mixed electric and magnetic coupling scheme is proposed to control the coupling coefficient variation. Theoretical analysis indicates that it is able to achieve desired coupling coefficients between the proposed resonators at various frequencies so as to obtain constant absolute bandwidth. Moreover, this half- wavelength resonator has a $Q$ higher than the quarter- and half- wavelength counterparts, thus resulting in low insertion loss. A filter of this type is designed to validate the proposed idea. To remove the spurious responses of the filter, a method is then introduced to suppress the second harmonic without degrading the passband performance. For demonstration, two frequency-agile filters with 60- and 80-MHz constant absolute bandwidth are implemented with the frequency tuning range from 680 to 1000 MHz. Comparisons of experimental and simulated results are presented to verify the theoretical predications. © 2010 IEEE.
Research Area(s)
- Bandpass filter, Constant bandwidth, Harmonic suppression, Q Factor, Tunable filter
Citation Format(s)
Low-loss frequency-agile bandpass filters with controllable bandwidth and suppressed second harmonic. / Zhang, Xiu Yin; Xue, Quan; Chan, Chi Hou et al.
In: IEEE Transactions on Microwave Theory and Techniques, Vol. 58, No. 6, 5463054, 06.2010, p. 1557-1564.
In: IEEE Transactions on Microwave Theory and Techniques, Vol. 58, No. 6, 5463054, 06.2010, p. 1557-1564.
Research output: Journal Publications and Reviews › RGC 21 - Publication in refereed journal › peer-review