Methods and apparatus for a frequency selective limiter (FSL) having a magnetic material substrate that tapers in thickness and supports a transmission line that has segments and bends. The segments, which differ in width and are substantially parallel to each other, such that each segment traverses the substrate on a constant thickness of the substrate.

A high-speed circuit includes a printed circuit board, a ground plane layer, a pair of first and second differential traces, and a cascading common mode filter. The printed circuit board has a first surface and an opposite second surface. The ground plane layer has a first surface in contact with the second surface of the printed circuit board. The pair of first and second differential traces are on the first surface of the printed circuit board. The first and second differential traces carry an electrical signal. The cascading common mode filter includes an outer and an inner common mode filter. The outer common mode filter includes a U-shaped void section on the first surface of the ground plane layer. The inner common mode filter includes an H-shaped void section on the first surface of the ground plane layer. The H-shaped void section is located proximate to the U-shaped void section.

A high-speed circuit includes a printed circuit board, a ground plane layer, a pair of first and second differential traces, and a cascading common mode filter. The printed circuit board has a first surface and an opposite second surface. The ground plane layer has a first surface in contact with the second surface of the printed circuit board. The pair of first and second differential traces are on the first surface of the printed circuit board. The first and second differential traces carry an electrical signal. The cascading common mode filter includes an outer and an inner common mode filter. The outer common mode filter includes a U-shaped void section on the first surface of the ground plane layer. The inner common mode filter includes an H-shaped void section on the first surface of the ground plane layer. The H-shaped void section is located proximate to the U-shaped void section.

A semiconductor technology implemented high-frequency channelized filter includes a dielectric substrate with metal traces disposed on one of two major surfaces of the substrate. An input and output port disposed on the substrate and one of the metal traces carrying a high-frequency signal to be filtered between the input and output port. Other of the metal traces are connected to the one metal trace at intervals along the length of the one metal trace each providing a reactance to the high-frequency signal where the reactance varies with frequency and additional traces of the metal traces serving as a reference ground for the one metal trace and the other metal traces. A silicon enclosure mounted to the substrate with a first planar surface with cavities in the enclosure that extend through the first surface, and internal walls within the silicon enclosure defining the cavities. A layer of conductive metal covers the first planar surface, cavities and the internal walls. The silicon enclosure having substantially continuous areas of metal on the first planar surface about the periphery of the silicon enclosure that engage corresponding areas of the additional traces about the periphery of the substrate. The cavities surround the respective other metal traces with the internal cavity walls engaging the additional traces adjacent the respective other metal traces to individually surround each of the other metal traces with a conductive metal thereby providing electromagnetic field isolation between each of the other metal traces.

A transmission line has a first conductor layer extending in a first direction, a second conductor layer disposed on a side of a first surface of the first conductor layer via a first dielectric layer, the second conductor layer extending in the first direction, and a third conductor layer disposed on a side of a second surface of the first conductor layer opposite to the first surface, via a second dielectric layer, the third conductor layer extending in the first direction, wherein a width, in a second direction intersecting the first direction, of each of the second conductor layer and the third conductor layer is different at a plurality of locations in the first direction, and the first conductor layer, the second conductor layer, and the third conductor layer at least partially overlap each other in a plan view from a normal direction of the first surface.

Disclosed are apparatuses and methods of tuning a radio frequency circuit using stub tuners and photoconductive switches. In one aspect an electromagnetic stub tuner apparatus is disclosed. the apparatus includes a transmission line, and a photoconductive switch positioned along the length of the transmission line. The photoconductive switch is configured to turn on or turn off, wherein an impedance of the transmission line is changed when the photoconductive switch is turned on compared to when the photoconductive switch is turned off. In another aspect, a method of tuning a radio frequency circuit is disclosed. In yet another aspect, a method of producing a radio frequency tuning circuit is disclosed.

A millimeter-wave antenna-in-package includes a substrate, and a radiation structure and a first antenna feeder that are disposed in the substrate. The first antenna feeder includes an antenna matching stub, a feeder transmission strap, and a first harmonic suppression unit. A first end of the antenna matching stub is connected to the radiation structure. The first harmonic suppression unit includes a first transmission part and a first bent part. A first end of the first bent part is connected to a first end of the first transmission part, and a second end of the first bent part and a second end of the first transmission part form a first opening. A second end of the antenna matching stub is connected to the feeder transmission strap through the first transmission part, and the feeder transmission strap extends along the first reference direction.

A multi-mode filter with a resonator having a plurality of resonator bodies which are rectangular prisms and the filter being configured with a through hole that electrically connects an input and an output to the center of a coupling structure between a respective pair of slabs. The multi-mode filter further comprising a plurality of coupling aperture segments which are coupling structures between each pair of resonator bodies or slabs such that two triangular apertures at opposite corners of at least two different slab-cube interfaces are utilized with the triangular apertures being diagonally opposed to one another across the respective interface.

A filter comprising a cavity, a circuit board located in the cavity, and a filter branch is provided. A power divider circuit is disposed on the circuit board, and includes an input end, a main feeder, and an output end, wherein both the input end and the output end are electrically connected to the main feeder, and the main feeder transmits a signal that is input at the input end and is output at the output end. The filter branch includes a first interface and a first filter line, wherein the first interface is disposed at an opening of the cavity, the first filter line is located outside the cavity, the first filter line is electrically connected to the first interface, and the first interface is electrically connected to the main feeder. The first filter line in the filter branch is disposed outside the cavity.

The present invention discloses an amplifier. The bias amplifier includes a signal input end, for inputting an input signal; a voltage input end, for inputting a source voltage; an amplifying circuit, for generating an amplified input signal according to the input signal, and the amplified input signal comprises a fundamental signal, a first harmonic signal and a second harmonic signal, wherein the first harmonic signal is a second order harmonic of the fundamental signal, and the second harmonic signal is a third order harmonic of the fundamental signal; a harmonic filter, coupled between the voltage input end and the amplifying circuit, for filtering the first harmonic signal and the second harmonic signal; and a signal output end, coupled to the harmonic filter, for outputting an output signal according to the amplified input signal.