Abstract: An electronic device includes a reader and a plurality of first coil units. The reader is configured to read at least one wireless signal. The reader is connected to a first coil unit of the first coil units to read the wireless signal in an original reading distance. Other first coil unit(s) of the first coil units is separately arranged in an order started from the first coil unit. Spacing between any two of the first coil units is lower than or equal to the original reading distance. The first coil units are configured to generate magnetic coupling with an adjacent first coil unit started from the first coil unit to extend the original reading distance as a first extended reading distance and adjust a direction of the first extended reading distance.

Abstract: An electronic device includes a reader and a plurality of first coil units. The reader is configured to read at least one wireless signal. The reader is connected to a first coil unit of the first coil units to read the wireless signal in an original reading distance. Other first coil unit(s) of the first coil units is separately arranged in an order started from the first coil unit. Spacing between any two of the first coil units is lower than or equal to the original reading distance. The first coil units are configured to generate magnetic coupling with an adjacent first coil unit started from the first coil unit to extend the original reading distance as a first extended reading distance and adjust a direction of the first extended reading distance.

Abstract: An electronic device includes a reader and a plurality of first coil units. The reader is configured to read at least one wireless signal. The reader is connected to a first coil unit of the first coil units to read the wireless signal in an original reading distance. Other first coil unit(s) of the first coil units is separately arranged in an order started from the first coil unit. Spacing between any two of the first coil units is lower than or equal to the original reading distance. The first coil units are configured to generate magnetic coupling with an adjacent first coil unit started from the first coil unit to extend the original reading distance as a first extended reading distance and adjust a direction of the first extended reading distance.

Abstract: A data random selection device includes a data generation module and a data reading module. The data generation module includes a RFID tag and indication units. The RFID tag stores and sends an identification code, and one of the indication units is randomly driven to generate an indication signal when the RFID tag sends the identification code. The data reading module includes a wireless radio frequency reader and an output unit. The wireless radio frequency reader receives the identification code and reads the indication value corresponding to the randomly driven indication unit. The output unit outputs identification code and the indication value.