DMS filter and duplexer for improving pass band flatness

A flatness and filter technology, applied in electrical components, impedance networks, etc., can solve problems such as increasing insertion loss, affecting device performance, and unreasonable interdigital parameters, eliminating passband notch and improving passband flatness. degree, reducing the effect of in-band insertion loss

Inactive Publication Date: 2021-03-05
CHENGDU PINNACLE MICROWAVE CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

For the longitudinally coupled resonator type DMS filter, the unreasonable setting of the interdigital parameters of the IDT (Int

Method used

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  • DMS filter and duplexer for improving pass band flatness
  • DMS filter and duplexer for improving pass band flatness
  • DMS filter and duplexer for improving pass band flatness

Examples

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Example Embodiment

[0024] A reconstructed filter of the ultrawne adjustment range provided by the present invention will be described in detail below with reference to the accompanying drawings and examples. It should be noted that the specific embodiments of the present invention are not limited to the embodiments provided.

[0025] An DMS filter for improving the passage flatness of the present invention, including: a piezoelectric substrate, and N input and output of the piezoelectric substrate, alternately distributed along the acoustic surface wave propagation direction The IDT, the two sides of the n IDT are provided with a reflective gate, and the end electrode of the adjacent two IDT refers to the opposite; in the n IDT, the X-x Tt and the n + 1-x IDT are mirror symmetry relationships. N is an odd number greater than or equal to 5; the total number of electrodes of each IDT refers to an odd number greater than or equal to 3.

[0026] It will be appreciated that in the embodiment of the prese...

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PUM

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Abstract

The invention provides a DMS filter and duplexer for improving passband flatness, and the DMS filter capable of improving the passband flatness comprises a piezoelectric substrate, and N input and output IDTs which are disposed on the piezoelectric substrate and are alternately distributed in a surface acoustic wave propagation direction, and two sides of each of the N IDTs are provided with reflecting gratings. The pointing directions of the end electrode fingers of two adjacent IDTs are opposite; in the N IDTs, the Xth IDT and the (N + 1-X) th IDT are in mirror symmetry, and N is an odd number larger than or equal to 5; the total number of the electrode fingers of each IDT is an odd number greater than or equal to 3. According to the DMS filter, through reasonable configuration of parameters of the IDT interdigital electrode, passband notch can be effectively eliminated, in-band insertion loss is obviously reduced, passband flatness is well improved, and the DMS filter can be used asa filter device of a duplexer and communication equipment as a good choice.

Description

technical field [0001] The invention relates to the technical field of microwave communication, in particular to a DMS filter and a duplexer for improving passband flatness. Background technique [0002] The double-mode surface acoustic wave filter (Double-mode SAW, referred to as DMS) structure has the advantages of miniaturization and high stability, and is widely used in the design of filters and duplexers. For the longitudinally coupled resonator type DMS filter, the unreasonable setting of the interdigital parameters of the IDT (Interdigital Transducer) may generate a notch in the passband, increase the insertion loss, and affect the performance of the device. Therefore, how to improve the current IDT structure settings to avoid notches in the passband and reduce insertion loss has become a problem to be solved. Contents of the invention [0003] The object of the present invention is to solve the above problems, and provide a DMS filter capable of reducing insertion...

Claims

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Application Information

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IPC IPC(8): H03H9/64H03H9/72
CPCH03H9/64H03H9/725
Inventor 赵孟娟董元旦杨涛安虹瑾
Owner CHENGDU PINNACLE MICROWAVE CO LTD
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