An electronic device may include a wireless circuit, and a coaxial cable device having an S-shaped balun segment coupled to the wireless circuit, and an antenna segment coupled to the S-shaped balun segment. The S-shaped balun segment may include a first inner conductor segment, and a first outer conductor segment surrounding the first inner conductor segment. The antenna segment may include a second inner conductor segment coupled to the first inner conductor segment, and a second outer conductor segment surrounding the second inner conductor segment and coupled to the first outer conductor segment, the second inner conductor segment extending from the second outer conductor segment.

An antenna assembly for use in a tile architecture antenna system. The antenna assembly comprises: i) a first substrate layer having a first surface; ii) a first antenna disposed in an X-Y plane on the first surface of the first substrate layer; iii) a second substrate layer having a first surface, the second substrate layer displaced in the Z-direction with respect to the X-Y plane on the first surface of the first substrate layer; and iv) a first tuning balun disposed on the first surface of the second substrate layer and coupled to the first antenna by means of a first feed via. The antenna assembly further comprises a first transmission line disposed on the first surface of the second substrate layer. The first transmission line is coupled to the first antenna by means of a second feed via.

An antenna assembly for use in a tile architecture antenna system. The antenna assembly comprises: i) a first substrate layer having a first surface; ii) a first antenna disposed in an X-Y plane on the first surface of the first substrate layer; iii) a second substrate layer having a first surface, the second substrate layer displaced in the Z-direction with respect to the X-Y plane on the first surface of the first substrate layer; and iv) a first tuning balun disposed on the first surface of the second substrate layer and coupled to the first antenna by means of a first feed via. The antenna assembly further comprises a first transmission line disposed on the first surface of the second substrate layer. The first transmission line is coupled to the first antenna by means of a second feed via.

The invention presents a LTCC balun filter using two out-of-phase filtering circuits. The LTCC balun filter is comprised of three half-wavelength resonators and grounds which are located on fourteen metal layers. Vias are utilized to connect different metal parts. The first, fourth, seventh, eleventh and fourteenth metal layers are the ground. The three half-wavelength resonators are on the second, third, fifth, sixth, eighth, ninth, tenth, twelfth and thirteenth metal layers. By adjusting the coupling parts of the three half-wavelength resonators, namely the lengths of the seventh, eighth, ninth, tenth and eleventh layers, as well as the distances between them, the coupling strength between the half-wavelength resonators can be tuned. In addition, the quality factor of the circuit can be improved by tuning the port positions. By using the multi-layer LTCC technology, the present invention has the advantage of compact size, novelty, creativity and practicability.

The invention presents a LTCC balun filter using two out-of-phase filtering circuits. The LTCC balun filter is comprised of three half-wavelength resonators and grounds which are located on fourteen metal layers. Vias are utilized to connect different metal parts. The first, fourth, seventh, eleventh and fourteenth metal layers are the ground. The three half-wavelength resonators are on the second, third, fifth, sixth, eighth, ninth, tenth, twelfth and thirteenth metal layers. By adjusting the coupling parts of the three half-wavelength resonators, namely the lengths of the seventh, eighth, ninth, tenth and eleventh layers, as well as the distances between them, the coupling strength between the half-wavelength resonators can be tuned. In addition, the quality factor of the circuit can be improved by tuning the port positions. By using the multi-layer LTCC technology, the present invention has the advantage of compact size, novelty, creativity and practicability.

A balun transformer includes an input terminal into which an unbalanced signal is input, a converter that includes at least a first signal line connected to the input terminal and that converts the unbalanced signal into a balanced signal, a first output terminal connected to the first signal line, a second output terminal from which the balanced signal is output, the balanced signal being also output from the first output terminal, and a capacitor connected between the input terminal and the second output terminal.

A balun transformer includes an input terminal into which an unbalanced signal is input, a converter that includes at least a first signal line connected to the input terminal and that converts the unbalanced signal into a balanced signal, a first output terminal connected to the first signal line, a second output terminal from which the balanced signal is output, the balanced signal being also output from the first output terminal, and a capacitor connected between the input terminal and the second output terminal.

A radiofrequency power amplifier includes a balun transformer and a plurality of power transistor pairs arranged in a push-pull configuration. The balun transformer has an unbalanced coil extending between a first single-ended signal terminal and a first reference, and a balanced coil extending between a first balanced signal terminal and a second balanced signal terminal. The balun transformer also includes an auxiliary coil electrically isolated from the unbalanced coil and the balanced coil. The auxiliary coil is inductively coupled to the unbalanced coil and extends between a third balanced signal terminal and a fourth balanced signal terminal forming a balanced combiner-divider. An output of a first one of the power transistor pairs is coupled to the first and second balanced signal terminals and an output of a second one of the power transistor pairs is coupled to the third and fourth balanced signal terminals.

A radiofrequency power amplifier includes a balun transformer and a plurality of power transistor pairs arranged in a push-pull configuration. The balun transformer has an unbalanced coil extending between a first single-ended signal terminal and a first reference, and a balanced coil extending between a first balanced signal terminal and a second balanced signal terminal. The balun transformer also includes an auxiliary coil electrically isolated from the unbalanced coil and the balanced coil. The auxiliary coil is inductively coupled to the unbalanced coil and extends between a third balanced signal terminal and a fourth balanced signal terminal forming a balanced combiner-divider. An output of a first one of the power transistor pairs is coupled to the first and second balanced signal terminals and an output of a second one of the power transistor pairs is coupled to the third and fourth balanced signal terminals.

A marchand balun with a reduced plane size is disclosed. The marchand balun provides two coupling units each having two transmission lines coupled to each other and having a length of λ/8, where λ is a characteristic wavelength of a signal subject to the marchand balun. The marchand balun further provides an additional unit, where two coupling unit and the additional unit are connected in series to each other. The additional unit is one of a transmission line with a length of λ/16 with one open end and a capacitor with one grounded end.