摘要 |
FIELD: radio engineering. ^ SUBSTANCE: identification device consists of casing, receiver-transmitter antenna, several acoustic channels, which are installed in different acoustic ducts. In every acoustic channel there is receiver-transmitter IDT and reflecting IDT in parallel acoustic channels with the same period L0i, which is different in different acoustic ducts, and frequency-selective multiple-stripe directional coupler between them. The distance between transducers is different in different acoustic ducts. Receiver-transmitter IDT in all acoustic ducts are made unidirectional with internal reflectors and connected to antenna in parallel. ^ EFFECT: increases reflection factor of surface acoustic waves from reflecting IDT in different acoustic channels. ^ 2 dwg |