Saw device with inclined reflectors and communication device using saw device

A communications device comprising a mixer, a surface acoustic wave device the input side of which being connected to the output side of said mixer, and an amplifier the input side of which being connected to the output side of said surface acoustic wave device, said surface acoustic wave device further comprising a piezoelectric substrate, input and output interdigital transducer electrodes provided on said piezoelectric substrate in a manner such that the directions of propagation of surface acoustic waves are parallel, a first reflector electrode provided at a predetermined distance from said input interdigital transducer electrode toward said output side of said surface acoustic waves, a second reflector electrode provided at a predetermined distance from said output interdigital transducer electrode in a manner such that it reflects the surface acoustic waves reflected by said first reflector electrode and propagates to said output interdigital transducer electrode, wherein Equation (1) is satisfied:

• 2(θ−5)≦tan−1(D/L)≦2(θ+5) (1)
• where
• θ:
• angle of inclination in degrees (excluding zero degree) of said first or said second reflector electrode relative to a plane perpendicular to the direction of propagation of surface acoustic waves of said input and output IDT electrodes;
• D:
• center-to-center distance in μm of the widths of said input and output IDT electrodes in the direction perpendicular to the direction of propagation of surface acoustic waves;
• L:
• center-to-center distance in μm of said first and second reflector electrodes.