A mobile device includes a hybrid antenna, a tunable circuit element, an RF (Radio Frequency) module, and a proximity sensor. The tunable circuit element provides an impedance value. The RF module generates RF power. The hybrid antenna is coupled through the tunable circuit element to the RF module. The proximity sensor is respectively coupled to the hybrid antenna, the tunable circuit element, and the RF module, and is configured to detect a specific distance between the hybrid antenna and a conductive element. The tunable circuit element and the RF module are operated according to relative information of the specific distance. If the specific distance is shorter than or equal to a first threshold distance, the RF module will reduce the RF power. If the specific distance is shorter than or equal to a second threshold distance, the tunable circuit element will change the impedance value.

A multi-band antenna having an aperture tuner is disclosed. The multi-band antenna may simultaneously transmit a first radio frequency (RF) signal and a second RF signal. The aperture tuner may modify a resonant frequency associated with one or more antenna elements of the multiband antenna in accordance with the first RF signal or the second RF signal. One or more of the antenna elements of the multi-band antenna may be disposed above and/or substantially parallel to other antenna elements. In some exemplary embodiments, an air gap may be formed between one or more antenna elements.

A dual band transmitter for transmitting a data signal in a first frequency or second frequency band. An antenna receives and sends data in one of the first and second frequency bands. An impedance matching network is connected in series with the antenna, and to a first node, and matches the impedance of the antenna to a predetermined value. The impedance matching network includes first and second antenna matching networks. The first antenna matching network is connected in series with the second matching network. In the first frequency band, the first antenna matching network matches the impedance of the antenna to the predetermined value, and in the second frequency band the second antenna matching network matches the impedance of the antenna to the predetermined value without affecting the first antenna matching network's matching in the first frequency band.

According to one embodiment, an antenna device includes a first antenna, a second antenna, a third antenna, a capacitor element, a high-frequency cable, and a base member. The first antenna includes a folded-type monopole element. The second antenna includes a monopole element. The third antenna includes a passive element. The capacitor element is between a feeding point and a stub in a backward-path portion of the first antenna. The high-frequency cable is connected to the feeding point. The base member is formed of a dielectric material and has first, second, and third surfaces located to extend in different directions. The first, second, and third antenna are located at the first, second, and third surfaces.

According to one embodiment, an antenna device includes a first antenna, a second antenna, a third antenna, a capacitor element, a high-frequency cable, and a base member. The first antenna includes a folded-type monopole element. The second antenna includes a monopole element. The third antenna includes a passive element. The capacitor element is between a feeding point and a stub in a backward-path portion of the first antenna. The high-frequency cable is connected to the feeding point. The base member is formed of a dielectric material and has first, second, and third surfaces located to extend in different directions. The first, second, and third antenna are located at the first, second, and third surfaces.

This disclosure is directed to broadband notch antennas. In one aspect, a notch antenna includes a dielectric plate having a first surface and a second surface located opposite the first surface. A conductive layer is disposed on the first surface and has a notch region that exposes the dielectric plate between edges of the conductive layer. The antenna also includes two or more frequency matching circuits that branch from the notch region. Each matching circuit is configured to send and receive electromagnetic radiation in a frequency band of a radio spectrum.

This disclosure is directed to broadband notch antennas. In one aspect, a notch antenna includes a dielectric plate having a first surface and a second surface located opposite the first surface. A conductive layer is disposed on the first surface and has a notch region that exposes the dielectric plate between edges of the conductive layer. The antenna also includes two or more frequency matching circuits that branch from the notch region. Each matching circuit is configured to send and receive electromagnetic radiation in a frequency band of a radio spectrum.

A dual band transmitter for transmitting a data signal in a first frequency or second frequency band. An antenna receives and sends data in one of the first and second frequency bands. An impedance matching network is connected in series with the antenna, and to a first node, and matches the impedance of the antenna to a predetermined value. The impedance matching network includes first and second antenna matching networks. The first antenna matching network is connected in series with the second matching network. In the first frequency band, the first antenna matching network matches the impedance of the antenna to the predetermined value, and in the second frequency band the second antenna matching network matches the impedance of the antenna to the predetermined value without affecting the first antenna matching network's matching in the first frequency band.

A circuit (4) for establishing a desired impedance value for a radio antenna (5) comprising a transistor (3) having an input (8) and an output terminal (6), and a printed radio frequency transformer comprising a first (1) and a second inductor (2), both inductors (1, 2) having a coupling factor value, and having a first and a second terminal (11, 12; 21, 22). The first terminal (11) of the first inductor (1) is adapted for connecting a radio antenna (5). The input terminal (8) of the transistor (3) is connected to the second terminal (12) of the first inductor (1), and the output terminal (6) of the transistor (3) is connected to the first terminal (21) of the second inductor (2), so that the desired impedance value (Z.sub.2) at the second terminal (22) of the second inductor (2) is determined by the inductance value of the second inductor (2).

A circuit (4) for establishing a desired impedance value for a radio antenna (5) comprising a transistor (3) having an input (8) and an output terminal (6), and a printed radio frequency transformer comprising a first (1) and a second inductor (2), both inductors (1, 2) having a coupling factor value, and having a first and a second terminal (11, 12; 21, 22). The first terminal (11) of the first inductor (1) is adapted for connecting a radio antenna (5). The input terminal (8) of the transistor (3) is connected to the second terminal (12) of the first inductor (1), and the output terminal (6) of the transistor (3) is connected to the first terminal (21) of the second inductor (2), so that the desired impedance value (Z.sub.2) at the second terminal (22) of the second inductor (2) is determined by the inductance value of the second inductor (2).