TRANSFORMER OF SURFACE ACOUSTIC WAVES (VARIANTS) Russian patent published in 2008 - IPC H03H9/145 

FIELD: acoustic electronics, namely, transformers of acoustic surface-waves operating in high harmonics.

SUBSTANCE: according to first variant of invention, periodical element of inter-digital structure of surface acoustic wave transformer is composed of two neighboring sections, each containing one or several posts. Number of posts in neighboring sections differs at least by one. Width of posts Δ is selected from intervals Δ≤0,61λ_a or 0,96λ_a≤Δ≤1,50λ_a, or 2,09λ_a≤Δ≤2,37λ_a. Distances between centers of posts of equal polarity are divisible by λ_a, and distances between centers of posts of different polarity equal to odd number of semi-waves λ_a/2, where λ_a - length of surface acoustic wave at the frequency of active harmonic. According to second variant of the invention, periodical element of inter-digital structure consists of two parts of identical length, each containing 2n+1 sections, where n>1. Topological pattern of second part is formed by means of displacement of topological pattern of first part for half a period of periodical element along the axis of inter-digital structure with following mirroring thereof in sliding symmetry plane, which passes through aforementioned axis, and number of posts in sections of different polarity of each part of periodical element differs at least by one. Three other variants of the invention are differentiated by mutual positioning of sections in identical parts of periodical element, by presence of non-identical parts of periodical element, by type of symmetry in positioning of sections in these parts and by number of posts in their sections.

EFFECT: increased transformation losses at inactive harmonics, reduced number of inactive transformation bands and increased frequency division between active and inactive harmonics.

5 cl, 11 dwg