Communication circuit with single element antenna for multi-frequency applications

A communication circuit, comprising:

• a single element antenna;
• a plurality of signal-limiting circuits;
• a high-frequency transceiver circuit adapted to be selectively coupled to the single element antenna via the plurality of signal-limiting circuits and tuned to operate at a high frequency carrier frequency;
• and
• a low-frequency transceiver circuit adapted to be selectively coupled to the single element antenna via the plurality of signal-limiting circuits and tuned to operate at a low frequency carrier frequency.

A communication circuit for multi-frequency communication, the communication circuit comprising:

• a single element antenna including a plurality of coils, wherein the plurality of coils consists of a first portion of coils and a second portion of coils;
• a high-frequency transceiver circuit adapted to be selectively coupled to the single element antenna in a first mode of operation of the communication circuit in which wireless communication with a first RF communication device at a high frequency carrier frequency via the single element antenna is enabled;
• and
• a low-frequency transceiver circuit adapted to be selectively coupled to the single element antenna in a second mode of operation of the communication circuit in which wireless communication with a second RF communication device at a low frequency carrier frequency via the single element antenna is enabled;
• wherein, in the first mode of operation, the first portion of coils is used for transmitting and receiving the wireless communication with the first RF communication device and the second portion of coils has one or more electromagnetic characteristics of a resonant stub;
• and
• wherein, in the second mode of operation, the first portion of coils and the second portion of coils are used for transmitting and receiving the wireless communication with the second RF communication device.