A method and apparatus for use in a digitally tuning a capacitor in an integrated circuit device is described. A Digitally Tuned Capacitor DTC is described which facilitates digitally controlling capacitance applied between a first and second terminal. In some embodiments, the first terminal comprises an RF+ terminal and the second terminal comprises an RF− terminal. In accordance with some embodiments, the DTCs comprise a plurality of sub-circuits ordered in significance from least significant bit (LSB) to most significant bit (MSB) sub-circuits, wherein the plurality of significant bit sub-circuits are coupled together in parallel, and wherein each sub-circuit has a first node coupled to the first RF terminal, and a second node coupled to the second RF terminal. The DTCs further include an input means for receiving a digital control word, wherein the digital control word comprises bits that are similarly ordered in significance from an LSB to an MSB.

A method and apparatus for use in a digitally tuning a capacitor in an integrated circuit device is described. A Digitally Tuned Capacitor DTC is described which facilitates digitally controlling capacitance applied between a first and second terminal. In some embodiments, the first terminal comprises an RF+ terminal and the second terminal comprises an RF− terminal. In accordance with some embodiments, the DTCs comprise a plurality of sub-circuits ordered in significance from least significant bit (LSB) to most significant bit (MSB) sub-circuits, wherein the plurality of significant bit sub-circuits are coupled together in parallel, and wherein each sub-circuit has a first node coupled to the first RF terminal, and a second node coupled to the second RF terminal. The DTCs further include an input means for receiving a digital control word, wherein the digital control word comprises bits that are similarly ordered in significance from an LSB to an MSB.

In one embodiment, a radio frequency (RF) impedance matching network includes electronically variable capacitors (EVCs), each EVC including discrete capacitors operably coupled in parallel. The discrete capacitors include fine capacitors each having a capacitance value substantially similar to a fine capacitance value, and coarse capacitors each having a capacitance value substantially similar to a coarse capacitance value. The increase of the variable total capacitance of each EVC is achieved by switching in more of the coarse capacitors or more of the fine capacitors than are already switched in without switching out a coarse capacitor that is already switched in.

In one embodiment, a radio frequency (RF) impedance matching network includes electronically variable capacitors (EVCs), each EVC including discrete capacitors operably coupled in parallel. The discrete capacitors include fine capacitors each having a capacitance value substantially similar to a fine capacitance value, and coarse capacitors each having a capacitance value substantially similar to a coarse capacitance value. The increase of the variable total capacitance of each EVC is achieved by switching in more of the coarse capacitors or more of the fine capacitors than are already switched in without switching out a coarse capacitor that is already switched in.

Devices and methods for improving voltage handling and/or bi-directionality of stacks of elements when connected between terminals are described. Such devices and method include use of symmetrical compensation capacitances, symmetrical series capacitors, or symmetrical sizing of the elements of the stack.

Devices and methods for improving voltage handling and/or bi-directionality of stacks of elements when connected between terminals are described. Such devices and method include use of symmetrical compensation capacitances, symmetrical series capacitors, or symmetrical sizing of the elements of the stack.

The present disclosure relates to tuning oscillatory systems. The teachings thereof may be embodied in a device having an adjustable capacitance value for tuning a first oscillatory system, connectable to a second oscillatory system having an unknown and weak coupling factor. The device may include: a first capacitor having a capacitance dependent upon a voltage; and a DC voltage source having a variable voltage applied to associated terminals; a series-connected arrangement of the DC voltage source and a decoupling element connected in parallel with terminals of the capacitor, to apply a variable bias voltage to the first capacitor. The voltage applied to the terminals of the DC voltage source may depend at least in part on a working frequency of the first oscillatory system.

A manufacturing method for a magnetic head forms a leading shield having a top surface. The top surface of the leading shield includes first and second portions. The second portion is located farther from a medium facing surface than is the first portion, and recessed from the first portion. A first gap layer is then formed on the first portion. Then, a magnetic layer including an initial first side shield, an initial second side shield and a coupling section connecting them is formed using a mold. The mold is then removed. The coupling section is then removed by etching the magnetic layer. A second gap layer and a main pole are then formed in this order.

A magnetic supercapacitor has a dielectric layer positioned between magnetic layers. The magnetic layers may comprise hard, soft magnetic material or magnetic exchange coupled magnet (i.e. soft and hard magnet composite). A magnetic flux generated by the magnetic layers increases the permittivity of the dielectric layer, thereby increasing the capacitance and, hence, stored energy of the supercapacitor. When the magnetic layers comprise soft magnetic material, the capacitance of the supercapacitor can be varied. In this regard, current passing through a conductive segment within close proximity to the magnetic layers may be controlled in order to tune the capacitance as may be desired.

A magnetic supercapacitor has a dielectric layer positioned between magnetic layers. The magnetic layers may comprise hard, soft magnetic material or magnetic exchange coupled magnet (i.e. soft and hard magnet composite). A magnetic flux generated by the magnetic layers increases the permittivity of the dielectric layer, thereby increasing the capacitance and, hence, stored energy of the supercapacitor. When the magnetic layers comprise soft magnetic material, the capacitance of the supercapacitor can be varied. In this regard, current passing through a conductive segment within close proximity to the magnetic layers may be controlled in order to tune the capacitance as may be desired.