Techniques for tuning a crossed-field antenna are provided. An example of an antenna system includes a D-plate with a D-plate feed conductor, such that the D-plate is a horizontal conductor raised above and insulated from a ground plane, an E-cylinder with an E-cylinder feed conductor, such that the E-cylinder is a vertical hollow conductive cylinder of smaller diameter than the D-plate, which is mounted concentrically above and insulated from the D-plate, a transmitter tuning circuit configured to receive a signal from a transmitter, an E-cylinder tuning circuit operably coupled to the transmitter tuning circuit and the E-cylinder feed conductor, and a D-plate tuning circuit operably coupled to the transmitter tuning circuit and the D-plate feed conductor.

Various embodiments are described that relate to an antenna. In one embodiment, the antenna can be a low profile, multi-band (e.g., dual band), emulated GPS constellation antenna. In one embodiment, the antenna can form a cube with two open sides and four circuit board sides. The four circuit boards can include a first hardware portion that allows functioning in a higher frequency band and a second hardware portion that allows functioning in a lower frequency band.

Various embodiments are described that relate to an antenna. In one embodiment, the antenna can be a low profile, multi-band (e.g., dual band), emulated GPS constellation antenna. In one embodiment, the antenna can form a cube with two open sides and four circuit board sides. The four circuit boards can include a first hardware portion that allows functioning in a higher frequency band and a second hardware portion that allows functioning in a lower frequency band.

A communication device includes an input port, a first output port, a second output port, a first output arm including one end connected to the first output port and another end connected to a branch point and including a first switching element configured to be shorted in a second mode, a second output arm including one end connected to the second output port and another end connected to the branch point and including a second switching element configured to be shorted in a first mode, and an input arm including one end connected to the input port and another end connected to the branch point and including a third switching element configured to introduce a discontinuity into a transmission line in the form of a matching element configured to change an impedance of the input arm in a divider mode.

A communication device includes an input port, a first output port, a second output port, a first output arm including one end connected to the first output port and another end connected to a branch point and including a first switching element configured to be shorted in a second mode, a second output arm including one end connected to the second output port and another end connected to the branch point and including a second switching element configured to be shorted in a first mode, and an input arm including one end connected to the input port and another end connected to the branch point and including a third switching element configured to introduce a discontinuity into a transmission line in the form of a matching element configured to change an impedance of the input arm in a divider mode.

A mobile device including a housing having a distal end, and electronics disposed in the housing configured to operate the mobile device. A connector is coupled to the electronics, and a Pi-shaped antenna has a coupling coupled to the connector to create a resonance using the connector. The Pi-shaped antenna and the connector are configured to wirelessly send and receive the wireless signals. An impedance matching network matches the impedance of the electronics to the Pi-shaped antenna. In some embodiments, the impedance matching network is switchable by the electronics and is configured to match an impedance of the electronics to the Pi-shaped antenna in at least two states, over multiple RF bands.

A mobile device including a housing having a distal end, and electronics disposed in the housing configured to operate the mobile device. A connector is coupled to the electronics, and a Pi-shaped antenna has a coupling coupled to the connector to create a resonance using the connector. The Pi-shaped antenna and the connector are configured to wirelessly send and receive the wireless signals. An impedance matching network matches the impedance of the electronics to the Pi-shaped antenna. In some embodiments, the impedance matching network is switchable by the electronics and is configured to match an impedance of the electronics to the Pi-shaped antenna in at least two states, over multiple RF bands.

A mobile device includes a ground element, a radiation element, a first short-circuited element, a second short-circuited element, and a switch element. The radiation element has a feeding point, a fixed grounding point, and a switchable grounding point. The fixed grounding point is coupled through the first short-circuited element to the ground element. The switchable grounding point is coupled through the second short-circuited element and the switch element to the ground element. An antenna structure is formed by the radiation element, the first short-circuited element, the second short-circuited element, and the switch element.

A mobile device includes a ground element, a radiation element, a first short-circuited element, a second short-circuited element, and a switch element. The radiation element has a feeding point, a fixed grounding point, and a switchable grounding point. The fixed grounding point is coupled through the first short-circuited element to the ground element. The switchable grounding point is coupled through the second short-circuited element and the switch element to the ground element. An antenna structure is formed by the radiation element, the first short-circuited element, the second short-circuited element, and the switch element.

Techniques and configurations are disclosed for bulk acoustic wave resonator (BAWR) tuner circuits and their use in integrated circuit (IC) packages and mobile communication devices for radio frequency (RF) communication. In some embodiments, a mobile communication device may include an antenna; a transmitter circuit having an output port, a tuner circuit having one or more BAWRs, an antenna port coupled to the antenna, a transmitter port coupled to the output port of the transmitter circuit, and a control port; and a control circuit, coupled to the control port, configured to adjust an impedance of the tuner circuit, via adjustment of a BAWR or another component of the tuner circuit, based at least in part on an impedance of the antenna. Other embodiments may be described and/or claimed.