Abstract: A laminated low-profile dual filter module for telecommunications devices and method provides both Groupe Spécial Mobile (GSM) and Digital Cellular System (DCS) transmit filters in a small package. The filter module comprises multiple layers of ceramic substrate with metal circuit patterns sandwiched between. Two separate filters are implemented within the layers, with a first filter comprising a first set of layers and the second filter adjoining within a second set of layers. Resonators for each filter are positioned at the opposite sides of the module, in order to avoid coupling between the resonators and ground layers are interspersed for isolation. Capacitors are implemented by a first plate defined by an area on one metal layer with the adjacent layers providing ground planes that form the second plate.

Abstract: An integrable circuit inductor (220) is formed from a patterned conductive material (110) that has a major portion completely encapsulated by a material (221, 223) that is substantially electrically non-conductive, and that has a magnetic response at the operating frequency of the inductor (220). Preferably, an amorphous ferrite material is used for encapsulation, which provides a closed magnetic flux path for the inductor (220) when processing a signal at its operating frequency.

Abstract: A laminated lowpass filter (100) is disclosed. The filter (100) has: a stack of dielectric substrates (301-312) having a ground via (209); a pi network coupled between an input (202) and an output (202'); and the ground via (209) is conductively filled and extends substantially through the sheets of dielectric (301-312) connecting a first ground plane (102) to a second ground plane (104) and is spaced a predetermined distance between a first and a second leg of the pi network, to define an isolation barrier that substantially minimizes the passage of stray signals therebetween.

Abstract: A simple and inexpensive device which is suited for real-time location of a fault occurring anywhere in a residential distribution system by analysis of the propogating fault signal considering the predetermined propagating velocity of the cable.

Abstract: A voltage variable capacitor (10) has as the base substrate a silicon wafer with a layer of high resistivity semiconductor material on top of the substrate. An insulating layer (16) of a metal oxide having a dielectric constant greater than the dielectric constant of the semiconductors (12), such as zirconium titanate, is formed on top of the high resistivity layer, and a metal electrode (18) is formed on the insulating layer (16). When the electrode is energized, a depletion layer (20) is formed in the high resistivity layer. By varying the voltage applied to the electrode, the capacitance of the device is altered.