HIGH-FREQUENCY REVERSE CONVERTER WITH NATURAL DIRECTIVITY OF EMISSION OF SURFACE ACOUSTIC WAVES Russian patent published in 2000 - IPC

FIELD: radio electronic equipment. SUBSTANCE: device may be used for filters of IF and carrier frequency in cordless telephones, pagers, mobile communication equipment, etc. Application of electric signal to unidirectional converter, which has elementary circuits of opposite-phase excitation electrodes and reflecting electrode, results in excitation of surface acoustic waves, which travel in direct and reverse directions. Natural directivity of emission is ensured by design of substrate, which is made from monocrystal, in which mechanical and electromagnetic constituents of propagating surface acoustic wave are shifted within range of 0^°< Δ_ϕ< ±90^°. Width of first, second and third excitation electrode in each elementary conforms to conditions λ/7 < b₁< 2/3, λ/7 < b₃< λ/4, λ/7 < b₅< λ/4, where λ is wavelength at mean frequency. Distance between first, second and third excitation electrodes conforms to conditions λ/7 < b₂< 2/4, λ/7 < b₄< 2/4. Width of reflecting electrode is within range of λ/7 < b₁< 2/3, λ/7 < b₁< 2/3. Distance between third excitation electrode and reflecting electrode is within range of λ/7 < b₆< 2/4. Reflecting electrode is connected to potential or ground adding bus. Polarity of connection of reflecting electrode to said buses is opposite to polarity of connection of third excitation electrode to same buses. Adjacent elementary circuits are arranged with period of L = (2n+1)•λ/2, n=1, 2, 3, .: Polarity of connection of adjacent elementary circuits to potential and ground adding buses is alternating. EFFECT: decreased insertion losses. 4 dwg