Single band and multiband wireless antennas are an important element of wireless systems. Competing tradeoffs of overall footprint, performance aspects such as impedance matching and cost require not only consideration but become significant when multiple antenna elements are employed within a single antenna such as to obtain circular polarization transmit and/or receive. Accordingly, it would be beneficial to provide designers of a wide range of electrical devices and systems with compact single or multiple frequency band antennas which, in addition to providing the controlled radiation pattern and circular polarization purity (where required) are impedance matched without substantially increasing the footprint of the antenna and/or the complexity of the microwave/RF circuit interfaced to them, whilst supporting multiple signals to/from multiple antenna elements in antennas employing them. Solutions present achieve this through provisioning one or more capacitive series reactances discretely or in combination with one or more shunt capacitive reactances.

An electronic device may be provided with an antenna module and a phased antenna array on the module. The module may include a logic board, an antenna board surface-mounted to the logic board, and a radio-frequency integrated circuit (RFIC) mounted surface-mounted to the logic board. The phased antenna array may include antennas embedded in the antenna board. The antennas may radiate at centimeter and/or millimeter wave frequencies. The logic board may form a radio-frequency interface between the RFIC and the antennas. Transmission lines in the logic board and the antenna board may include impedance matching segments that help to match the impedance of the RFIC to the impedance of the antennas. The module may efficiently utilize space within the device without sacrificing radio-frequency performance.

An electronic device may be provided with an antenna module and a phased antenna array on the module. The module may include a logic board, an antenna board surface-mounted to the logic board, and a radio-frequency integrated circuit (RFIC) mounted surface-mounted to the logic board. The phased antenna array may include antennas embedded in the antenna board. The antennas may radiate at centimeter and/or millimeter wave frequencies. The logic board may form a radio-frequency interface between the RFIC and the antennas. Transmission lines in the logic board and the antenna board may include impedance matching segments that help to match the impedance of the RFIC to the impedance of the antennas. The module may efficiently utilize space within the device without sacrificing radio-frequency performance.

A dual-feed loop antenna structure adapted to be disposed on a substrate includes two loop antennas and two open-loop grounding radiators. Each of the loop antennas is used for resonating at a first frequency band and a second frequency band and includes a feed-in end and a ground segment. The two open-loop grounding radiators are located between the two loop antennas. Each of the open-loop grounding radiators extends from the ground segment of the corresponding loop antenna. A coupling gap is formed between the two open-loop grounding radiators. One of the loop antennas and the open-loop grounding radiator connected thereto completely overlap the other loop antenna and the other open-loop grounding radiator connected thereto after being mirrored and reversed. An electronic device is further provided.

A dual-feed loop antenna structure adapted to be disposed on a substrate includes two loop antennas and two open-loop grounding radiators. Each of the loop antennas is used for resonating at a first frequency band and a second frequency band and includes a feed-in end and a ground segment. The two open-loop grounding radiators are located between the two loop antennas. Each of the open-loop grounding radiators extends from the ground segment of the corresponding loop antenna. A coupling gap is formed between the two open-loop grounding radiators. One of the loop antennas and the open-loop grounding radiator connected thereto completely overlap the other loop antenna and the other open-loop grounding radiator connected thereto after being mirrored and reversed. An electronic device is further provided.

A method for reducing a quantity of cable runs to antennas can include the step of providing a circuit of reactive elements coupled between an input terminal and at least two output terminals. The circuit can be used to separate a broadband signal into two or more disjoint expected frequency ranges. The circuit can match the impedance at the at least two output terminals to the impedance expected by the antennas. The elements of the circuit can have reactances and arrangement so that when a broadband RF signal is applied at the input terminal, two or more disjoint expected frequencies can be applied to the respective output terminals. The power at each output terminal can sufficiently match the antennas' expected power, and insertion losses can be minimized.

A method for reducing a quantity of cable runs to antennas can include the step of providing a circuit of reactive elements coupled between an input terminal and at least two output terminals. The circuit can be used to separate a broadband signal into two or more disjoint expected frequency ranges. The circuit can match the impedance at the at least two output terminals to the impedance expected by the antennas. The elements of the circuit can have reactances and arrangement so that when a broadband RF signal is applied at the input terminal, two or more disjoint expected frequencies can be applied to the respective output terminals. The power at each output terminal can sufficiently match the antennas' expected power, and insertion losses can be minimized.

In an embodiment, an electronic device may include a housing having an inner space, a first printed circuit board including a wireless communication circuit, an antenna structure connected to the wireless communication circuit through a first electrical path, and a tunable circuit having a first resistance value and disposed on a second electrical path. The electronic device may further include a low-resistance circuit disposed on a third electrical path branched from the second electrical path, and including a resistor and an inductor, the resistor having a second resistance value determined based on the first resistance value, and the inductor having a constant inductance value and disposed between the resistor and the ground. The electronic device may also include at least one processor configured to control the tunable circuit.

A multi-resonant, electrically-small antenna having a first helical arm and a second helical arm. The first helical arm encircles a first central axis and includes a proximal end. A radius between the first helical arm and the first central axis decreases in a distal direction away from the proximal end of the first helical arm. The second helical arm is nested in the first helical arm and encircles a second central axis. The second helical arm also includes a proximal end. A radius between the second helical arm and the second central axis decreases in a distal direction away from the proximal end of the second helical arm.

A multi-resonant, electrically-small antenna having a first helical arm and a second helical arm. The first helical arm encircles a first central axis and includes a proximal end. A radius between the first helical arm and the first central axis decreases in a distal direction away from the proximal end of the first helical arm. The second helical arm is nested in the first helical arm and encircles a second central axis. The second helical arm also includes a proximal end. A radius between the second helical arm and the second central axis decreases in a distal direction away from the proximal end of the second helical arm.