Surface acoustic wave filter with low linear phase fan-shaped structure

Abstract

The invention belongs to the technical field of surface acoustic waves, and particularly relates to a surface acoustic wave filter with a low linear phase fan-shaped structure, which comprises an input transducer, a shielding strip, an output end transducer and a peripheral matching circuit, the input transducer, the shielding strip, the output end transducer and the peripheral matching circuit are all arranged on a niobium niobate 128-degree Y-X cut type wafer substrate; the shielding strip is of a hollow structure and is arranged between the input transducer and the output transducer; the peripheral matching circuit is arranged at the input end and the output end of the fan-shaped surface acoustic wave filter; sound absorption glue is coated on two end surfaces of the fan-shaped surface acoustic wave filter; and by arranging the shielding strips with the hollow fan-shaped structures, the problem that the phase in the passband of the surface acoustic wave filter is relatively large is solved.

Description

technical field [0001] The invention belongs to the technical field of surface acoustic waves, and in particular relates to a surface acoustic filter with a low linear phase sector structure. Background technique [0002] The acoustic surface filter is a kind of input interdigital transducer made on the piezoelectric substrate that converts the electrical signal into an acoustic signal and propagates along the surface of the substrate, and then converts the acoustic signal into an electrical signal by the output interdigital transducer , which implements a filter for filtering electrical signals in two conversions. [0003] With the development of science and technology, SAW filters are widely used in military fields, short-wave radio stations, wireless transmitters, receivers and other civilian fields; therefore, in the market, the frequency bandwidth is about 65%, and the passband The SAW filter with good ripple and small group delay fluctuation has great demand. The exi...

AI Technical Summary

Problems solved by technology

The existing SAW filter with a frequency bandwidth of about 65% is generally a conventional SAW filter, but the insertion loss of the conventional SAW filter is very large, and its linear phase degree is also large, and the traditional SAW filter The dual-channel multiple coupler design is generally used in the design of the coupler, which is large in size and does not have practical value.

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