Wideband love wave filters operating in GHz range on Cu-grating/rotated-YX-LiNbO/sub 3/-substrate structure

Hashimoto, Ken–ya; Asano, Hiroki; Matsuda, Kenji; Yokoyama, N.; Omori, Tatsuya; Yamaguchi, M.

doi:10.1109/ultsym.2004.1418039

Cited by 34 publications

(21 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It has been suggested that the application of highly piezoelectric non-leaky share-horizontal (SH) type SAWs propagating under very thick gratings on YX-LiNbO 3 may be one of the candidates for the present purpose [1], [2]. For example, the authors have proposed an ultra-wideband ladder type filter with a small insertion loss [3], consisting of resonators employing SH type SAWs on Cugrating/15 • YX-LiNbO 3 structure [4]; its minimum insertion loss of less than 1 dB and extremely wide passband of 18% around 1 GHz are experimentally achieved as shown in Fig. 1 [5].…”

Section: Introductionmentioning

confidence: 99%

P6G-2 Synthesis of Frequency Response for Wideband SAW Ladder Type Filters

Omori

Tanaka²,

Hashimoto³

et al. 2007

2007 IEEE Ultrasonics Symposium Proceedings

Self Cite

View full text Add to dashboard Cite

Numerical synthesis of frequency response is discussed for a ladder type filter consisting of ultra-wideband SAW resonators on Cu-grating/15 • YX-LiNbO3 structure. For the synthesis, two parameters of each resonator, i.e., the static capacitance and resonant frequency were numerically optimised, while the capacitance ratio and figure of merit were fixed at specific values determined by substrates and grating electrodes employed. First, six-stage SAW ladder type filters having the passband width of 7 to 21% were designed. The result showed that the specified bandwidth is successfully synthesised. Next, a six-stage ladder type filter having the passband width of 8% was fabricated on Cugrating/15 • YX-LiNbO3 structure for experimental discussion. It was shown that the measured frequency response of the filter was in good agreement with the design, where some in-band spurious dips were removed by weighted dummy electrodes. By making analysis on the behaviour of resonant and anti-resonant frequencies of each resonator, it is shown that the method can be extended to the synthesis of filters having sophisticated frequency responses. The result suggested that the proposed method could become one of the powerful design tools for SAW ladder type filters with specified passband width.

show abstract

Section: Introductionmentioning

confidence: 99%

P6G-2 Synthesis of Frequency Response for Wideband SAW Ladder Type Filters

Omori

Tanaka²,

Hashimoto³

et al. 2007

2007 IEEE Ultrasonics Symposium Proceedings

Self Cite

View full text Add to dashboard Cite

show abstract

“…The spurious Rayleigh-type mode perturbs the frequency response between resonant and anti-resonant frequencies. Though the piezoelectric coupling of this mode (k 2 =0.075%) is much lower than that of the non-leaky mode (k 2 =30%), it is expected to deteriorate the performance of SAW filter in the passband, as shown in Fig.9 of [5]. For example, if propagation loss in the substrate material provides quality factor about 800, the peak to peak ripple about 1.5 dB, caused by parasitic mode, can be expected inside the filter passband.…”

Section: Theoretical Investigation Of Two Surface Modesmentioning

confidence: 99%

“…In [3,[5][6][7] the non-leaky mode propagating in 15°YX LN with heavy electrodes is called 'Love wave' or 'SH wave', and the spurious mode is referred to as 'Rayleigh wave'. As shown in [2], though for unloaded surface one of two modes has polarization of 'Rayleigh-type' SAW, such classification may be confusing if two modes are considered in wide intervals of rotation angles and electrode thicknesses.…”

Section: Theoretical Investigation Of Two Surface Modesmentioning

confidence: 99%

See 1 more Smart Citation

Optimal cut of lithium niobate with suppressed Rayleigh-type mode for application in resonator SAW filters

Naumenko

Abbott²

2008

2008 IEEE Ultrasonics Symposium

View full text Add to dashboard Cite

Results of resonators constructed on rotated YX lithium niobate (LiNbO 3 ), to provide minimum coupling of the spurious Rayleigh-type mode are reported. The resonator employs non-leaky waves which result when the metal grating's electrodes are sufficiently heavy to suppress attenuation of leaky waves. The coupling of two SAW modes propagating in rotated YX cuts was estimated as function of cut angle and electrode thickness, with Al or Cu as electrode material. The optimal orientation, 19°YX for Al grating or 20°YX for Cu grating, is compared with previously reported 15°YX cut. If the electrode thickness is optimized to suppress the spurious mode, in 15°YX the coupling of this mode grows fast with variation of frequency or electrode thickness because of close proximity between the velocities of two modes. In 19°YX cut the resonance of the spurious mode is located in the middle of the interval between the resonance and anti-resonance of non-leaky SAW mode. The spurious mode is made less sensitive to variations of frequency or metal thickness and provides better performance of resonator filters. This conclusion is confirmed experimentally.

show abstract

“…A leaky SAW (LSAW) on a 0-15°Y X-LiNbO 3 substrate has a high electromechanical coupling factor [7], but its SAW has a leaky component. As a result, in order to create a low-loss resonator with no leaky component across a wide range, an Au or Cu electrode with slow acoustic velocity is used on the substrate surface [8], and there are reports [9] of a wideband resonator with a bandwidth of 12% using a Cu electrode. In order to obtain an even higher electromechanical coupling factor, we evaluated a configuration with a Cu electrode embedded in the substrate (below referred to as a grooved electrode in a substrate) instead of a conventional electrode on a substrate (below, an electrode on a substrate).…”

Section: Introductionmentioning

confidence: 99%

Ultra‐wideband SAW resonator composed of grooved Cu electrodes and its application to tunable filters

Kadota

Kimura

Ida

2013

Elect Comm in Japan

View full text Add to dashboard Cite

A cognitive radio system, which is being investigated in order to use limited frequency resources effectively, requires a tunable filter with a wide variable frequency range. A wideband resonator is required to realize a tunable filter. It was reported that a resonator composed of a Cu electrode/15° YX-LiNbO 3 had a large bandwidth of 12%. We attempted to fabricate a one-port resonator composed of a grooved Cu electrode/4° YX-LiNbO 3 . This resonator was applied to a tunable filter, and a tunable filter having a tunable range of 6.8% in the center frequency was experimentally realized using a bandpass-type filter circuit, and one having a tunable range of 9 to 12% was theoretically realized using a ladder-type filter circuit.

show abstract

Wideband love wave filters operating in GHz range on Cu-grating/rotated-YX-LiNbO/sub 3/-substrate structure

Cited by 34 publications

References 9 publications

P6G-2 Synthesis of Frequency Response for Wideband SAW Ladder Type Filters

P6G-2 Synthesis of Frequency Response for Wideband SAW Ladder Type Filters

Optimal cut of lithium niobate with suppressed Rayleigh-type mode for application in resonator SAW filters

Ultra‐wideband SAW resonator composed of grooved Cu electrodes and its application to tunable filters

Contact Info

Product

Resources

About