A wideband SAW resonator and its application to a VCO for mobile radio transceivers

Hikita, M.; Sumioka, A.; Tabuchi, T.

doi:10.1109/25.330148

Cited by 10 publications

(3 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Since surface acoustic wave (SAW) resonators are advantageous in reducing the size and weight of devices, they are widely used for high-frequency filters [1,2] and voltage-controlled oscillators (VCO) [3][4][5] in mobile communications terminals. High-frequency VCOs are required to have an expanded variable range of oscillation frequency and reduced sideband phase noise.…”

Section: Introductionmentioning

confidence: 99%

Love‐wave‐type/Rayleigh‐wave‐type SAW resonators with thick Al‐grating structure

Isobe

Hikita

Asai

2005

Electron Comm Jpn Pt II

View full text Add to dashboard Cite

SUMMARYA Love-wave SAW propagating on a thick Al grating on a LiNbO 3 piezoelectric substrate exhibits a resonant characteristic with an extremely small capacitance ratio γ (= 3.0) while it elastically couples with Rayleigh waves in a complex manner. In the application to a resonator, the Rayleigh wave becomes spurious and must be suppressed sufficiently. With a view to development of a broadband SAW resonator for a VCO, the propagation/reflection characteristics of this Love-wave/Rayleigh-wave configuration are analyzed. The following results are found by simulation and experiments. (1) Both the Love wave and Rayleigh wave have extremely wide reflection bandwidths. (2) Two types of spurious Rayleigh wave appear in the resonant characteristics. (3) The stopband of the Rayleigh wave is superior in reflection characteristic to the Love wave. It is also demonstrated experimentally that a broadband SAW-VCO can be realized if the VCO oscillation frequency is chosen within the Rayleigh wave stopband after the Al film thickness is optimized.

show abstract

Section: Introductionmentioning

confidence: 99%

Love‐wave‐type/Rayleigh‐wave‐type SAW resonators with thick Al‐grating structure

Isobe

Hikita

Asai

2005

Electron Comm Jpn Pt II

View full text Add to dashboard Cite

show abstract

“…Therefore, SAW filters for cellular phones, SAW diplexers [13], and timing extraction high-Q filters for optical communication [4] have already been developed. However, it is generally difficult to take a wide tuning range of the oscillation frequency [6,7]. However, it is generally difficult to take a wide tuning range of the oscillation frequency [6,7].…”

Section: Introductionmentioning

confidence: 99%

“…On the other hand, the voltage-controlled oscillator (VCO) using a SAW resonator [5] is advantageous for miniaturization with an excellent C/N. However, it is generally difficult to take a wide tuning range of the oscillation frequency [6,7].…”

Section: Introductionmentioning

confidence: 99%

Fabrication method for grating‐mode‐type SAW resonator used in voltage‐controlled oscillator: optimum shape for electrode fingers and investigation of accurate process techniques

Asai¹,

Hikita²,

Isobe³

et al. 2001

Electron. Comm. Jpn. Pt. II

View full text Add to dashboard Cite

SUMMARYAn optimum electrode finger shape is obtained for the grating-mode-type SAW resonator on a 15° YXLiNbO 3 with a large relative bandwidth used for a high-C/N broadband VCO. Spurious responses by Rayleigh wave need to be suppressed completely in the SAW resonator. Its impedance characteristics are extremely sensitive to the variations of electrode finger linewidth and film thickness. The specifications for the film thickness and linewidth of the electrode finger are derived by simulation and experiment. It is demonstrated that the electrode finger film thickness of h/O 0 = 0.1325 and the relative electrode finger linewidth ratio of L / L S 0.575 are standard and their deviations need to be controlled accurately in fabrication. Assuming applications to industrial wireless terminals at 170 and 420 MHz, process accuracy enhancement is discussed so that the electrode finger specifications are satisfied. In the present SAW resonator with a thick electrode finger, an antireflection film is introduced in the photoresist process. Al-Cu alloy is used for the electrode fingers to produce an excellent impedance characteristic. The VCO using the present SAW resonator satisfies the specifications of the above wireless terminals. © 2001 Scripta Technica, Electron Comm Jpn Pt 2, 84(9): 1120, 2001

show abstract

Investigation of new‐mode‐type SAWs by procedures combined with finite‐element and analytical method, and their applications for devices used in mobile communications

Isobe

Hikita

Asai

et al. 2001

Electron Comm Jpn Pt II

View full text Add to dashboard Cite

SUMMARYSimulations using a combination of the finite-element method and the analytical method as well as experiments are used to study new-mode-type SAWs. First, in 171°YZc-LiNbO 3 , it is found that there exists a longitudinal leaky SAW with a high acoustic velocity and a high Q in a grating structure with an Al film thickness of 0.084 wavelength. The acoustic velocity is 6100 to 6500 m/s and the Q values are more than 4000 (computed) at both the resonance and antiresonance points. These excellent properties are suitable for high-frequency SAW devices. Next, in 15°YX-LiNbO 3 , it is found that there exists a grating mode SAW of a transverse wave type in a grating structure with an Al film thickness of 0.125 wavelength. In this case, k 2 has an extremely large value of 28.5% and hence the mode is suitable for a SAW resonator for use in a voltage-controlled oscillator. By means of this SAW, SAW-VCOs at 400 and 170 MHz for mobile communication are fabricated. At 400 MHz, the frequency variable width is 54 MHz (3.2%/V) and the phase noise is less than 115 dBc/Hz at 25 kHz; the corresponding values at 170 MHz are 24 MHz (3.4%/V) and < 12 dBc/Hz at 25 kHz. © 2001 Scripta Technica, Electron Comm Jpn Pt 2, 84(4): 4958, 2001

show abstract

A wideband SAW resonator and its application to a VCO for mobile radio transceivers

Cited by 10 publications

References 10 publications

Love‐wave‐type/Rayleigh‐wave‐type SAW resonators with thick Al‐grating structure

Love‐wave‐type/Rayleigh‐wave‐type SAW resonators with thick Al‐grating structure

Fabrication method for grating‐mode‐type SAW resonator used in voltage‐controlled oscillator: optimum shape for electrode fingers and investigation of accurate process techniques

Investigation of new‐mode‐type SAWs by procedures combined with finite‐element and analytical method, and their applications for devices used in mobile communications

Contact Info

Product

Resources

About