© The Institution of Engineering and Technology
This Letter presents a novel tunable balanced bandpass filter with high common-mode (CM) suppression by using discriminating coupling. Four half-wavelength resonators terminated with varactors are utilised to obtain the tunable responses. The high CM suppression is realised by discriminating coupling between feeding structures and resonators, which blocks the CM signals. An experimental tunable balanced bandpass filter is implemented which achieve the continuous tuning range from 0.84 to 1.15 GHz and more than 50 dB CM rejection levels.
References
-
-
1)
-
4. Li, Y.C., Xue, Q.: ‘Tunable balanced bandpass filter with constant bandwidth and high common-mode suppression’, IEEE Trans. Microw. Theory Tech., 2011, 59, (10), pp. 2452–2460 (doi: 10.1109/TMTT.2011.2161325).
-
2)
-
3. Mao, J.R., Che, W.Q., Ma, Y.L., Chen, J.X.: ‘Tunable differential-mode bandpass filters with wide tuning range and high common-mode suppression’, IET Proc. Microw. Antennas Propag., 2014, 8, (6), pp. 437–444 (doi: 10.1049/iet-map.2012.0203).
-
3)
-
5. Zhang, X.Y., Xue, Q.: ‘Harmonic-suppressed bandpass filter based on discriminating coupling’, IEEE Microw. Wirel. Compon. Lett., 2009, 19, (11), pp. 695–697 (doi: 10.1109/LMWC.2009.2032002).
-
4)
-
2. Chen, J.-X., Shao, C., Lu, Q.-Y.: ‘Compact LTCC balanced bandpass filter using distributed-element resonator’, Electron. Lett., 2013, 49, (5), pp. 354–356 (doi: 10.1049/el.2012.4071).
-
5)
-
2. Prieto, A.F., Martel, J., Medina, F., Mesa, F., Boix, R.R.: ‘Compact balanced FSIR bandpass filter modified for enhancing common-mode suppression’, IEEE Microw. Wirel. Compon. Lett., 2015, 25, (3), pp. 154–156 (doi: 10.1109/LMWC.2015.2390492).
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content/journals/10.1049/el.2015.1922
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Tunable balanced bandpass filter with high common-mode suppression