Abstract: A bend sensor for use in wirelessly sensing an amount of bend of a joint or other monitored object. The sensor includes a radio frequency (RF) antenna and an integrated circuit linked to the antenna. The integrated circuit or chip is passive and responds to, or is powered by, a read signal received by the antenna to transmit a reflected signal via the antenna such as to an RFID reader. The sensor also includes a transducer linked to the integrated circuit. The transducer defines reflecting impedance, which modulates amplitude and phase of the reflected signal. The transducer has impedance varying with deformation or bend. In one example, the transducer includes an upper conductor, and the amount of the deformation is defined by a bend radius of the upper conductor. The read signal may be at 5 GHz or higher such with the antenna and the transducer being microwave structures.

Abstract: A bend sensor for use in wirelessly sensing an amount of bend of a joint or other monitored object. The sensor includes a radio frequency (RF) antenna and an integrated circuit linked to the antenna. The integrated circuit or chip is passive and responds to, or is powered by, a read signal received by the antenna to transmit a reflected signal via the antenna such as to an RFID reader. The sensor also includes a transducer linked to the integrated circuit. The transducer defines reflecting impedance, which modulates amplitude and phase of the reflected signal. The transducer has impedance varying with deformation or bend. In one example, the transducer includes an upper conductor, and the amount of the deformation is defined by a bend radius of the upper conductor. The read signal may be at 5 GHz or higher such with the antenna and the transducer being microwave structures.