Details

Autor(en) / Beteiligte

• Zakharov, A. V.
• Rozenko, S. A.
• Pinchuk, L. S.

Titel

Microstrip Bandpass Filter with Left Transmission Zero Controlled by Parasitic Cross Coupling

Ist Teil von

• Radioelectronics and communications systems, 2018-06, Vol.61 (6), p.274-282

Ort / Verlag

Moscow: Pleiades Publishing

Erscheinungsjahr

2018

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• A third-order microstrip filter is proposed and studied. It is characterized by a left-handed transmission zero f z , caused by the parasitic cross-coupling between non-adjacent resonators. The filter contains a half-wave middle resonator and two quarter-wave resonators located from different sides, near the open ends of the middle resonator. The coupling between all resonators has magnetic character, and the zero of the filter transfer function f z is located to the left of the center frequency of the passband f 0 . Such filter is described by a modified coupling matrix, where one of the main coupling coefficients is artificially assigned a minus sign. In the proposed filter design, for a given value of the main coupling coefficients, it is possible to provide different values of the cross-coupling coefficient by appropriately selecting the design parameters. This allows adjusting the zero position of the transmission f z for a given bandwidth of the filter, thereby changing the left slope of the amplitude-frequency characteristic. A sequence of steps is proposed for constructing such a filter. The measured and simulated frequency characteristics of the experimental filter are given.