Suppression of bulk waves in surface acoustic wave filter
Journal Title: Вісник НТУУ КПІ. Серія Радіотехніка, Радіоапаратобудування - Year 2016, Vol 0, Issue 67
Abstract
Introduction. One of the dominant second order effects in devices based on surface acoustic waves (SAW) is the excitation of parasitic bulk acoustic waves (BAW). Attention is drawn to the lack of effectiveness of traditional BAW suppression ways. Traditional ways of suppressing the bulk acoustic waves. Provides an overview of how suppression of parasitic BAW to SAW filters. One way allows to reach a record level of BAW suppression (−65 dB) due to the significant mechanical weakening of the acoustic line of the filter. Narrowband surface acoustic wave filter. It is found that in the SAW filter with an extremely high level of out-of-band suppression (−72 dB) traditional ways do not provide the required level of suppression of BAW. Wave heterogeneity of special shape. Tested the effectiveness of the authors proposed way of BAW suppression in a narrow-band SAW filter with an extremely high level of out-of-band suppression. A deep closed groove which is cut in the lower surface of the acoustic line of filter reduces the level of BAW to −70 dB, and the strength of the acoustic line of filter is almost not reduced. The dependence of suppression the bulk acoustic waves from the parameters of the wave heterogeneity. The dependence of the relative level (B) of suppression the slow quasi-shear bulk acoustic waves from the depth of the closed groove was investigated. It was found a monotonic increase in the level of B with increasing groove depth. Level B = −70 dB was obtained when the thickness of the gap between the bottom of the groove and the working surface of the acoustic line was (for different filter samples). Conclusion. The effectiveness of the authors proposed way of suppression the slow quasi-shear BAW in SAW filters is proved. A deep closed groove which is cut into the bottom surface of the acoustic line of filter can suppress slow quasi-shear BAW to a level of −70 dB.
Authors and Affiliations
E. Nelin, Yu. Nepochatykh
Keywords
Related Articles
- EP ID EP308259
- DOI 10.20535/RADAP.2016.67.65-70
- Views 95
- Downloads 0
The account of the statistical, given for correction programs of search defuses of radioelectronic means
The description of algorithm and results of development of the software package for accumulation and use of the empirical information is given, with the purpose of increase of efficiency of diagnosing of radioelectronic...
Ganzenko Generation and properties of Gold’s sequence
The article shows principles generation of Gold's sequences, shown a block diagram of sequence generator, based on shift registers and step by step description of its work. We calculated the spectral characteristics of s...
Analysis of the microwave self-noise influencing on the parameters of the Dicke radiometer
Introduction. The application domains of the radiometric measuring are described and the basic types of radiometers are listed. The best "price – measurement precision" index (in the authors' opinion ) has a Dicke radiom...
Identification of a semiconductor by facility of the nonlinear location on two harmonicas
In article is brought theoretical explanation of a experimentally received effect of the occurrence the negative differential resistance on the volt-ampere characteristic of a diode structures at influence upon them comp...
The methods of the square quad-ridged waveguides eigen functions and eigen values computation with the field behavior near-by a rib accounting
A methods of the regular square quad-ridged waveguides eigen functions eigen values computation is developed. By means of the partial areas method the analytical solutions of the wave equalization are received for a Z-sh...