Topic
Crystal filter
About: Crystal filter is a research topic. Over the lifetime, 673 publications have been published within this topic receiving 6008 citations.
Papers published on a yearly basis
1 / 2
Papers
Patent•
21 May 1997TL;DR: In this article, the authors proposed a Bulk Acoustic Wave Resonator-Stacked Crystal Filter (BAWR-SCF) circuit, which consists of a first BAW resonator connected in series in the first lead, and a second BAW Resonator connected between the first and second leads.
Abstract: There is provided a Bulk Acoustic Wave Resonator-Stacked Crystal Filter (BAWR-SCF) filtering circuit or device. The BAWR-SCF circuit comprises a first pair of ports, a second pair of ports, a first lead that is connected between a first and a second one of the first pair of ports, and a second lead that is connected between a first and a second one of the second pair of ports. The BAWR-SCF circuit also comprises a first BAW resonator connected in series in the first lead, and a second BAW resonator connected between the first and second leads. The BAWR-SCF further comprises a Stacked Crystal Filter (SCF) having first and second terminals connected in the first lead between the first BAW resonator and the second one of the first pair of ports. The SCF also has a third terminal that is connected to a node of the second lead. The frequency response of the BAWR-SCF circuit has steeply-sloped upper and lower edges that are similar to those yielded by ladder filters which are constructed primarily of BAW resonators. The upper and lower notches of the BAWR-SCF circuit's frequency response are also similar to those yielded by ladder filters which are constructed primarily of BAW resonators. The BAWR-SCF circuit also provides stopband attenuation characteristics that are similar to those yielded by SCFs. Additional BAW resonators connected in a ladder configuration and/or SCFs may also be provided in the BAWR-SCF circuit.
145 citations
TL;DR: In this paper, a 5-band waveguide bandpass filter based on spherical resonators has been designed, and fabricated by 3-D printing, and a special topology has been proposed to relieve the impact of the first three higher order modes in the resonator and ultimately to achieve a good out-of-band rejection.
Abstract: A fifth order X-band waveguide bandpass filter, based on spherical resonators, has been designed, and fabricated by 3-D printing. In comparison with rectangular waveguide, spherical resonators have a higher unloaded quality factor, but at the same time suffer from closer higher order modes. In this letter, a special topology has been proposed to relieve the impact of the first three higher order modes in the resonator and ultimately to achieve a good out-of-band rejection. Stereolithography based 3-D printing is used to build the filter structure from polymer and a 25 $\mu{\rm m}$ thick copper layer is deposited to the filter. The measurement result of the filter has an excellent agreement with the simulations. The filter is also considerably lighter than a similar metal filter.
143 citations
Patent•
8 Apr 1999TL;DR: In this paper, a multi-pole Bulk Acoustic Wave Resonator-Stacked Crystal Filter (Multi-pole BAWR-SCF) filtering circuit was proposed, which includes a plurality of impedance inverting elements and at least one inductive element.
Abstract: There is provided a Multi-pole Bulk Acoustic Wave Resonator-Stacked Crystal Filter (Multi-pole BAWR-SCF) filtering circuit or device. In one embodiment the Multi-pole BAWR-SCF circuit comprises a first pair of ports, a second pair of ports, a first lead that is coupled between a first and a second one of the first pair of ports, and a second lead that is coupled between a first and a second one of the second pair of ports. The Multi-pole BAWR-SCF circuit also comprises at least one BAW resonator that is coupled in series in the first lead, and at least one Stacked Crystal Filter (SCF). The SCF has first and second terminals that are coupled in the first lead, and a third terminal that is coupled in the second lead. The Multi-pole BAWR-SCF circuit further comprises a plurality of impedance inverting elements and at least one inductive element. Each individual one of the impedance inverting elements is coupled across the first and second leads, and the at least one inductive element is coupled in parallel with the at least one BAW resonator. The Multi-pole BAWR-SCF circuit yields improved frequency response characteristics relative to those that are typically yielded by at least some conventional multi-pole filters, and includes a reduced number of passive components relative to the number of such components included in at least some conventional multi-pole filters.
121 citations
16 Dec 2002
TL;DR: Coupled resonator filters (CRF) as discussed by the authors are a new form of bulk acoustic wave device that involves the vertical stacking of resonators and can be thought of as a variation on the better known stacked crystal filter (SCF).
Abstract: Coupled resonator filters (CRF) are a new form of bulk acoustic wave device that involves the vertical stacking of resonators. In that regard, the CRF can be thought of as a variation on the better known stacked crystal filter (SCF). However, the CRF is actually somewhat more analogous to the monolithic crystal filter (MCF) that was a mainstay in filters for low frequency applications. This paper reviews coupled resonator concepts, briefly including the MCF, describes the design and modeling of CRFs, and presents representative experimental results.
118 citations
Patent•
21 Dec 1992TL;DR: In this article, a monolithic multipole stacked crystal filter with a shunt inductor is proposed. But the shunt is not connected between the two 2-port filters.
Abstract: This invention discloses a monolithic multipole stacked crystal filter comprised of a series of cascaded 2-port semiconductor bulk acoustic resonator stacked crystal filters electrically cascaded and a shunt inductor connected between each of the 2-port filters. Each of the 2-port filters including a first and second piezoelectric layer, typically aluminum nitride. A first input electrode is positioned on a top surface of one of the piezoelectric layers and a second output electrode is positioned on a bottom surface of the other of the piezoelectric layers. A ground electrode is positioned between the piezoelectric layers. In this regard, the piezoelectric layers will resonate at a resonant frequency and provide bandpass filter characteristics. The complete monolithic multipole filter provides control of the passband shape which yields highly desirable filter characteristics.
105 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 5 |
| 2020 | 5 |
| 2019 | 2 |
| 2018 | 3 |
| 2017 | 11 |
| 2016 | 18 |