Proximity sensor, method for sensing proximity of wireless device and body part of user, and wireless device

A proximity sensor, applied to a wireless device, comprising:

• an antenna electrode serving as at least a part of an antenna of the wireless device;
• and
• a detecting circuitry electrically coupled to the antenna electrode, wherein the detecting circuitry is configured to detect an electrical parameter of the antenna electrode, and output an operating signal based on the electrical parameter;
• wherein a distance between the antenna electrode and a body part of a user is determined based on the operating signal;
• wherein the antenna electrode is electrically coupled to radio frequency (RF) circuitry of the wireless device, and the RF circuitry is configured to transmit or receive wireless signals via the antenna;
• wherein the electrical parameter reflects capacitance between the antenna electrode and a referential point, and the detecting circuitry comprises capacitance sensing circuitry configured to detect the capacitance;
• wherein the operating signal is in a third state in a case that the capacitance is higher than a threshold capacitance, and in a fourth state in a case that the capacitance is lower than the threshold capacitance;
• wherein when the wireless device performs wireless communication via electromagnetic waves of a first frequency, the operating signal is in a third state in a case that the return loss is higher than a first threshold, and in a fourth state in a case that the return loss is lower than the first threshold;
• when the wireless device performs wireless communication via electromagnetic waves of a second frequency, the operating signal is in the third state in a case that the return loss is lower than a second threshold, and in the fourth state in a case that the return loss is higher than the second threshold;
• and
• the first frequency is lower than the second frequency.