An apparatus is provided that includes an inductor, a pair of modulating coils, a first switch and a second switch. The inductor includes two sub-loops electrically coupled with each other. The modulating coils include a first modulating coil and a second modulating coil respectively disposed corresponding to each of the two sub-loops. The first switch and the second switch are respectively disposed at the first modulating coil and the second modulating coil. Each of the first modulating coil and the second modulating coil forms an open loop when the first switch and the second switch are under an open status, and each of the first modulating coil and the second modulating coil forms a closed loop when the first switch and the second switch are under a closed status that enables a modulation of an inductance of the inductor.

A tunable inductor arrangeable on a chip or substrate comprises a first winding part connected at one end to a first input of the tunable inductor arrangement, a second winding part connected at one end to the other end of the first winding part, a third winding part connected at one end to a second input of the tunable inductor arrangement, a fourth winding part connected at one end to the other end of the third winding part, and a switch arrangement arranged. The switch arrangement tunes the tunable inductor by selectively connecting the first and fourth winding parts in parallel and the second and third winding parts in parallel, with the parallel couplings in series between the first and second inputs, or connecting the first, second, fourth and third winding parts in series between the first and second inputs. Corresponding transceivers, communication devices, methods and computer programs are disclosed.

A tunable inductor arrangeable on a chip or substrate comprises a first winding part connected at one end to a first input of the tunable inductor arrangement, a second winding part connected at one end to the other end of the first winding part, a third winding part connected at one end to a second input of the tunable inductor arrangement, a fourth winding part connected at one end to the other end of the third winding part, and a switch arrangement arranged. The switch arrangement tunes the tunable inductor by selectively connecting the first and fourth winding parts in parallel and the second and third winding parts in parallel, with the parallel couplings in series between the first and second inputs, or connecting the first, second, fourth and third winding parts in series between the first and second inputs. Corresponding transceivers, communication devices, methods and computer programs are disclosed.

A method of providing a single structure multiple mode antenna is described. The antenna is preferably constructed having a first inductor coil that is electrically connected in series with a second inductor coil. The antenna is constructed having a plurality of electrical connections positioned along the first and second inductor coils. A plurality of terminals is connected to the electrical connections that facilitate numerous electrical connections and enables the antenna to be selectively tuned to various frequencies and frequency bands.

A transformer that can easily cope with various input voltage specifications and that, has improved productivity is obtained. A transformer includes: a core portion for forming a magnetic circuit; and a primary-side winding and a secondary-side winding wound at the core portion. One or both of the primary-side winding and the secondary-side winding are divided into a plurality of division windings, and each of the plurality of the division windings of the at least one divided winding has a wound part wound at the core portion, and two extending members extending from both ends of the wound part. The extending members of the plurality of the division windings of the at least one divided winding are mutually connected, and a number of turns in the transformer of the at least one divided winding is set.

A dry type cast coil transformer (28) includes a hollow body (29), a dome structure (26) extending from the body, and undulation structure (30), defining at least a portion of an outer surface of the dome structure, constructed and arranged to increase an electrical track path in the dome structure.

A switching power supply device that switches setting of an output voltage based on an external signal according to one or more embodiments includes: a transformer including a primary winding and n secondary windings; n synchronous rectification elements provided, corresponding to the n secondary windings; and n−1 switch elements that switch the secondary windings. Each of the n−1 switch elements is kept on or off according to a high or low voltage value out of set voltages of the output voltage, and all or any of the n synchronous rectification elements are selected to synchronously rectify pulse voltage of the secondary windings, and when operation with a high set value of the output voltage stops, a synchronous rectification element used to output the high set value performs switching operation until the output voltage goes down to the low voltage value of the set voltages of the output voltage.

A printed circuit board, and more particularly, a printed circuit board that provides a variable inductance. A printed circuit board includes: an inductor positioned between an input terminal and an output terminal; a switch connected to the inductor; and a controller connected to the output terminal and the switch and outputting a control signal for controlling the switch to the switch, wherein the inductor is formed of a plurality of circuit patterns having different plating thicknesses and signal paths for the plurality of circuit patterns are selectively connected by operation of the switch according to the control signal.

A printed circuit board, and more particularly, a printed circuit board that provides a variable inductance. A printed circuit board includes: an inductor positioned between an input terminal and an output terminal; a switch connected to the inductor; and a controller connected to the output terminal and the switch and outputting a control signal for controlling the switch to the switch, wherein the inductor is formed of a plurality of circuit patterns having different plating thicknesses and signal paths for the plurality of circuit patterns are selectively connected by operation of the switch according to the control signal.

A spring unit includes a mechanical spring means having a spring direction and being located between a first spring support and a second spring support, which first and second spring supports are movable in relation to each other in the spring direction. The spring unit further includes a first actuation member facing the rear side of the first spring support and a second actuation member facing the rear side of the second spring support, which first and second actuating members are movable relative to each other and relative to the first and second spring supports in the spring direction.