A container includes a surface and a first resonance portion. The surface defines a volume of the container, and the first resonance portion includes an assembly of three-dimensional (3D) carbon-containing structures printed on the surface of the container using one or more first carbon-based inks. The first resonance portion is configured to indicate a presence of an item within the container by resonating at one or more predetermined frequencies in response to an electromagnetic radiation ping associated with a user device located a distance from the container. In some implementations, the container may include a second resonance portion including an assembly of 3D carbon-containing structures printed on the surface of the container using one or more second carbon-based inks, the one or more second carbon-based inks being different than the one or more first carbon-based inks.

A container includes a surface and an electromagnetic state sensing device including one or more resonance portions printed on the surface of the container. Each resonance portion may include an assembly of 3D carbon-containing structures that convey information of a stored item by resonating at a predetermined frequency in response to an electromagnetic radiation ping received from a user device. The resonance portions may include at least a first resonance portion configured to convey product identification information of the stored item and a second resonance portion configured to convey product state information of the stored item. The first resonance portion conveys product identification information of the stored item in response to a first electromagnetic radiation ping having a first frequency, and the second resonance portion conveys product state information of the stored item in response to a second electromagnetic radiation ping having a second frequency different than the first frequency.

A container includes a surface and a first resonance portion. The surface defines a volume of the container, and the first resonance portion includes an assembly of three-dimensional (3D) carbon-containing structures printed on the surface of the container using one or more first carbon-based inks. The first resonance portion is configured to indicate a presence of an item within the container by resonating at one or more predetermined frequencies in response to an electromagnetic radiation ping associated with a user device located a distance from the container. In some implementations, the container may include a second resonance portion including an assembly of 3D carbon-containing structures printed on the surface of the container using one or more second carbon-based inks, the one or more second carbon-based inks being different than the one or more first carbon-based inks.

A method of interrogating an acoustic wave sensor comprises transmitting, by an interrogator, an interrogation radiofrequency signal to the acoustic wave sensor by way of a transmission antenna, receiving, by the interrogator, a response radiofrequency signal from the acoustic wave sensor by way of a reception antenna, and processing by a processing means of the interrogator the received response radiofrequency signal to obtain in-phase and quadrature components both in the time domain and the frequency domain, determining by the processing means perturbations of the obtained in-phase and quadrature components both in the time domain and the frequency domain and determining by the processing means a value of a measurand based on the detected perturbations.

A wireless device can transmit, over a communications network to a server, a request to download an application associated with obtaining information pertaining to a package. The wireless device can receive the requested application from the server, and can execute the application using the one or more processors. The wireless device can transmit one or more electromagnetic pings in a vicinity of the package, receive a first return signal from the first resonance portion, and receive a second return signal from the second resonance portion. The first return signal has a frequency based on the one or more electromagnetic pings and a first resonant frequency of the first resonance portion, and the second return signal has a frequency based on the one or more electromagnetic pings and a second resonant frequency of the second resonance portion.

The invention concerns a RFID tag (1) configured to transmit a predetermined code (3K) as a RF backscattered radiation (2) in response to an impinging RF signal (41). The RFID tag (1) is configured to react to an impinging signal at a predetermined reference frequency (23) with a reference backscattered signal (2R). The RFID tag (1) is also configured and to react to an impinging signal (41) at any of a group of transmission frequencies (21, 22) with coding backscattered signals (2F-G) whose amplitudes (20A, 20B) relative to the amplitude (20R) of the reference backscattered signal define the code (3K). The invention further concerns a RFID reader (4), a kit (5) and a method for transmitting a message from a device (1) to a reader (4) as a RF backscattered radiation (2) in response to an impinging RF signal (41).

A wireless device can transmit, over a communications network to a server, a request to download an application associated with obtaining information pertaining to a package. The wireless device can receive the requested application from the server, and can execute the application using the one or more processors. The wireless device can transmit one or more electromagnetic pings in a vicinity of the package, receive a first return signal from the first resonance portion, and receive a second return signal from the second resonance portion. The first return signal has a frequency based on the one or more electromagnetic pings and a first resonant frequency of the first resonance portion, and the second return signal has a frequency based on the one or more electromagnetic pings and a second resonant frequency of the second resonance portion.

Remote keyless entry (RKE) systems and devices are described. The RKE devices include one or more passive radios that respond to an interrogation signal from an interrogating device such as a vehicle. The passive radio sends a responsive signal that can include a decaying portion representing a ringdown signal. The passive radio includes a SAW resonator in some situations.

A container includes a surface and a first resonance portion. The surface defines a volume of the container, and the first resonance portion includes an assembly of three-dimensional (3D) carbon-containing structures printed on the surface of the container using one or more first carbon-based inks. The first resonance portion is configured to indicate a presence of an item within the container by resonating at one or more predetermined frequencies in response to an electromagnetic radiation ping associated with a user device located a distance from the container. In some implementations, the container may include a second resonance portion including an assembly of 3D carbon-containing structures printed on the surface of the container using one or more second carbon-based inks, the one or more second carbon-based inks being different than the one or more first carbon-based inks.

A container includes a surface defining a volume of the container, a first resonance portion disposed on a first portion of the surface of the container using one or more first carbon-based inks, and a second resonance portion disposed on a second portion of the surface of the container using one or more second carbon-based inks different than the one or more first carbon-based inks. The first resonance portion can resonate within a first range of frequencies in response to one or more electromagnetic pings received from a user device, and the second resonance portion can resonate within a second range of frequencies in response to the one or more electromagnetic pings, the second range of frequencies being different than the first range of frequencies. In some instances, the user device may be a smartphone, a radio frequency identification (RFID) reader, or a near-field communication (NFC) device.