Journal of Radio Electronics. eISSN 1684-1719. 2024. №8

Full text in Russian (pdf)

DOI: https://doi.org/10.30898/1684-1719.2024.8.12

METHOD OF INCREASING THERMOSTABILITY
OF SAW FILTERS USING THERMOMECHANICAL SYSTEMs

B.A. Kosarev^1,2, I.A. Korzh²

¹Omsk Scientific Center SB RAS (Institute of Radiophysics and Physical Electronics)
644024, Russia, Omsk, Marksa ave., h. 15

²Omsk Scientific-Research Institute of Instrument Engineering
644071, Russia, Omsk, Maslennikova, 231

The paper was received July, 10 2024.

Abstract. SAW filters are widely used in electronic equipment. The changes in temperature cause SAW filters frequency shifts associated with degradation of electronic equipment performance. Thermal deformation of packages and piezoelectric substrates cause SAW filters frequency shifts. The frequency shifts of the SAW filters are compensated by thermomechanical systems. In this paper two new types of thermomechanical systems have been proposed. Piezoelectric substrate banding is proposed to suppress the frequency shift. If the filter has a predominant frequency shift in the high temperature region, then as the temperature increases, the thermomechanical system must bend the substrate towards the bottom of the housing. If the filter has a predominant frequency shift in the low temperature region, then as the temperature decreases, the thermomechanical system should bend the substrate in the direction of the housing cover. The 70 MHz samples of SAW filters with fractional bandwidth of 0.04 % on YX/33° quartz have shown in the temperature range from −40 ºC to +80 ºC a frequency shift of less than ±2 kHz.

Key words: SAW filter, frequency shift, thermomechanical system, piezoelectric substrate.

Financing: The work was carried out according to the state task of the Omsk Scientific Center SB RAS (project registration number 122011200349-3).

Corresponding author: Boris Kosarev, BorisK_88@mail.ru

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For citation:

Kosarev B.A., Korzh I.A. Method of increasing thermostability of saw filters using thermomechanical systems. // Journal of Radio Electronics. – 2024. – №. 8. https://doi.org/10.30898/1684-1719.2024.8.12 (In Russian)