Proximity sensor using antennas of a user device

A non-transitory computer-readable storage medium storing instructions that when executed by a computing system of a user device cause the computing system to perform operations, comprising:

• receiving a measurement of a first magnitude of mutual coupling between a plurality of antennas of the user device, wherein the first magnitude of mutual coupling is based on a transmitted signal by one of the plurality of antennas and a received signal received by another one of the plurality of antennas, the received signal representing the transmitted signal measured by the other one of the plurality of antennas;
• using the first magnitude of mutual coupling, distinguishing between the user device being proximate to free space, proximate to a first object type or proximate to a second object type, wherein the first object type comprises non-water-based objects that do not absorb electromagnetic radiation and the second object type comprises objects that absorb electromagnetic radiation, wherein the distinguishing comprises:
• detecting an object proximate to the user device using the first magnitude of mutual coupling;
• determining that the object is of the second object type when the first magnitude of mutual coupling does not exceed a first threshold value;
• and
• determining that the object is of the first object type when the first magnitude of mutual coupling exceeds the first threshold value and does not exceeds a second threshold value, the second threshold value being greater than the first threshold value.

A non-transitory computer-readable storage medium storing instructions that when executed by a computing system of a user device cause the computing system to perform operations, comprising:

• receiving a measurement of a first magnitude of mutual coupling between a plurality of antennas of the user device, wherein the first magnitude of mutual coupling is based on a transmitted signal by one of the plurality of antennas and a received signal received by another one of the plurality of antennas, the received signal representing the transmitted signal measured by the other one of the plurality of antennas;
• using the first magnitude of mutual coupling, distinguishing between the user device being proximate to free space, proximate to a first object type or proximate to a second object type, wherein the first object type comprises non-water-based objects that do not absorb electromagnetic radiation and the second object type comprises objects that absorb electromagnetic radiation;
• instructing a first antenna of the plurality of antennas to transmit a first signal;
• receiving another indication of a first received signal on a second antenna of the plurality of antennas, the first received signal representing the transmitted first signal measured by the second antenna;
• computing the first magnitude of mutual coupling between the first antenna and the second antenna using the transmitted first signal and the first received signal;
• receiving a second indication of a second received signal measured on a third antenna of the plurality of antennas, the second received signal representing the transmitted first signal measured on the third antenna;
• and
• computing a second magnitude of mutual coupling between the first antenna and the third antenna using the first received signal and the second received signal.

A user device, comprising:

• a first antenna configured to communicate first data in a transmitting mode of the user device and to transmit second data in a sensing mode of the user device;
• a second antenna configured to communicate third data in the transmitting mode and to receive the second data in the sensing mode;
• and
• a processing device coupled to the first antenna and the second antenna, wherein the processing device is configured to measure a mutual coupling magnitude between the first antenna and the second antenna and to detect a presence of an object in proximity to one or both of the first antenna and the second antenna using the mutual coupling magnitude, wherein the processing device is configured to distinguish whether the object is of a first object type that absorbs electromagnetic radiation or of a second object type that does not absorb electromagnetic radiation using the mutual coupling magnitude.

An apparatus comprising

• a processing component coupled to a plurality of antennas each configured to configured to transmit, receive, or both transmit and receive information to or from another device, wherein the processing component is configured to determine a mutual coupling magnitude between two or more of the plurality of antennas, to determine a presence of an object in proximity to one or more of the plurality of antennas using the mutual coupling magnitude, and to determine when the object is one that absorbs electromagnetic radiation using the mutual coupling magnitude, wherein the processing component is further to:
• determine that the object is one that absorbs electromagnetic radiation when the mutual coupling magnitude between the two or more of the plurality of antennas does not exceed a first threshold value;
• and
• determine that the detected object is of a second object type that does not absorb electromagnetic radiation when the mutual coupling magnitude between the two or more of the plurality of antennas exceeds the first threshold value and does not exceeds a second threshold value, the second threshold value being greater than the first threshold value.