A radio frequency filters and methods for implementing the filters in multilayer metallic-dielectric structures, such as printed circuit boards (PCB), low temperature co-fired ceramic (LTCC) components and integrated circuits (IC). The methods and filters utilize vertical stacking of transmission lines and related frequency-selective structures to obtain compact implementation of filters of high order. The methods and filters are applicable to a variety of filter types and related structures such as multiplexers.

To provide a multilayer substrate for transmitting/receiving a high frequency signal, the substrate having a simplified configuration and excellent high frequency characteristics. This disclosure pertains to a multilayer substrate provided with: a plurality of dielectric layers laminated together with ground layers interposed therebetween; and a signal line for inputting and outputting a signal, the signal line being formed on the surface of the dielectric layer. The plurality of ground layers include an input-side ground layer part formed in the region on the signal-input side of the signal line, an output-side ground layer part formed in the region on the signal-output side of the signal line, and an intermediate ground layer part formed in the region between the input-side ground layer part and the output-side ground layer part. The input-side ground layer part and the output-side ground layer part each have fewer layers than the intermediate ground layer part.

A compact band pass filter (BPF), including a first transmission line electromagnetically coupled to a second transmission line; and an isolating surface positioned between the first transmission line and the second transmission line, wherein the isolating surface includes at least one aperture designed to produce a desired electromagnetic coupling between the first transmission line and the second transmission line wherein the coupling produces a passband such that certain frequencies within an input transmission signal are filtered out.

A high-frequency signal transmission line includes an element, a linear signal line provided at the element and including a first end and a second end, and at least one ground conductor provided at the element and extending along the signal line. The element includes stacked insulating layers. The ground conductor is positioned opposite to the signal line with the insulating layer positioned therebetween. The ground conductor is a contiguous conductor. The signal line, the ground conductor, and the element generate a characteristic impedance. The signal line includes a first section and a second section. The first section is an uninterrupted section generating a characteristic impedance greater than or equal to a first characteristic impedance at the first end and including the first end. The second section generates a characteristic impedance less than the first characteristic impedance and is adjacent to the first section. The second section is longer than the first section. The signal line is wider in the second section than in the first section.

A signal transmission line includes a laminate, a signal conductor, a hollow portion, and a reinforcing conductor. The laminate includes a flexible laminate including resin layers each of which has flexibility. The signal conductor extends in a signal transmission direction of the laminate and is disposed in an intermediate position in a laminating direction of the resin layers. The hollow portion is in the laminate and defined by an opening provided at a portion of the plurality of resin layers. The reinforcing conductor is in the laminate. The hollow portion is disposed at a position overlapping with the signal conductor, in a plan view of the laminate from a surface perpendicular or substantially perpendicular to the laminating direction. The reinforcing conductor is disposed at a position different from the position of the hollow portion in a plan view.

A coaxial transmission line, e.g. a coaxial cable, includes an inner electrical conductor, an outer electrical conductor, a dielectric region between the inner electrical conductor and the outer electrical conductor, and an electrically thin resistive layer within the dielectric region and concentric with the inner electrical conductor and the outer electrical conductor. The electrically thin resistive layer is a resistive layer configured to be transparent to a subtantially transverse-electromagnetic (TEM) mode of transmission, while absorbing higher order modes of transmission.

Embodiments of the invention include a packaged device with transmission lines that have an extended thickness, and methods of making such device. According to an embodiment, the packaged device may include a first dielectric layer and a first transmission line formed over the first dielectric layer. Embodiments may then include a second dielectric layer formed over the transmission line and the first dielectric layer. According to an embodiment, a first line via may be formed through the second dielectric layer and electrically coupled to the first transmission line. In some embodiments, the first line via extends substantially along the length of the first transmission line.

An exemplary device includes a dielectric layer and a transmission line structure disposed in the dielectric layer. The transmission line structure includes a first metal line disposed between a second metal line and a third metal line. Dielectric islands are disposed in a first region and a second region of the dielectric layer. The first region of the dielectric layer is between the first metal line and the second metal line. The second region of the dielectric layer is between the first metal line and the third metal line. A dielectric constant of the dielectric islands is greater than a dielectric constant of the dielectric layer. The dielectric islands may be doped sections of the dielectric layer. In some embodiments, the dielectric islands in the first region are aligned with the dielectric islands in the second region along a direction perpendicular to a lengthwise direction of the first metal line.

A semiconductor package is provided. The semiconductor package includes a semiconductor die, a stack of polymer layers, redistribution elements and a passive filter. The polymer layers cover a front surface of the semiconductor die. The redistribution elements and the passive filter are disposed in the stack of polymer layers. The passive filter includes a ground plane and conductive patches. The ground plane is overlapped with the conductive patches, and the conductive patches are laterally separated from one another. The ground plane is electrically coupled to a reference voltage. The conductive patches are electrically connected to the ground plane, electrically floated, or electrically coupled to a direct current (DC) voltage.

A Printed Circuit Board (PCB) and methods for manufacturing the PCB board are provided. The PCB includes a plurality of layers; a signal pad, at a first layer of the plurality of layers, connected to a signal transmission trace strip line, at a second layer of the plurality of layers, wherein the signal pad is configured to connect to a surface mount Radio Frequency (RF) connector that is configured to interface an RF signal with the signal pad; a PCB ground cage structure through the plurality of layers, surrounding the signal pad; and extended ground reference planes located at the first layer and a third layer of the plurality of layers, wherein the extended ground reference planes extend into a volume of the PCB ground cage structure.