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 radio frequency apparatus includes a power amplifier circuit, a signal coupling circuit, an extraction circuit, and a harmonic filter circuit. The power amplifier circuit is configured to amplify a differential signal to output a to-be-filtered signal. The signal coupling circuit includes a primary side inductor and a secondary side inductor. The signal coupling circuit is configured to convert the to-be-filtered signal received by the primary side inductor into a single-ended signal outputted from the secondary side inductor. The extraction circuit has a center tap. The extraction circuit is configured to inductively couple to the primary side inductor and output a common mode signal from the center tap. The harmonic filter circuit is configured to perform a harmonic filtering on the single-ended signal according to the common mode signal, such that the secondary side inductor of the signal coupling circuit outputs a filtered signal.

A magnetically tunable ferrimagnetic filter, including a top casing, a top magnetic conductor, a bottom magnetic conductor, coils, a balance coil, ferrimagnetic-based filters, and a bottom casing. The ferrimagnetic-based filters utilize ferrimagnetic resonator elements, such as yttrium-iron-garnet (YIG), configured to reduce a magnetic gap of the YIG filter and thereby to improve performance.

Disclosed are techniques for wireless communication. In an aspect, a band-pass filter of a radio frequency front end (RFFE) of a user equipment (UE) receives an analog radio frequency (RF) signal having a first bandwidth associated with a first sampling rate, the analog RF signal comprising a positioning reference signal (PRS). An analog-to-digital converter (ADC) of the UE samples the analog RF signal at a second sampling rate to generate a digital RF signal representing the analog RF signal, wherein the ADC operates at a second bandwidth lower than the first bandwidth, and wherein the second sampling rate is lower than the first sampling rate by an inverse of a folding factor for the first bandwidth. The digital RF signal is then output to a baseband processor of the UE.

A BAW resonator filter can include a BAW resonator pass-band filter ladder, the BAW resonator pass-band filter ladder can be configured to pass frequency components of an input signal in a pass-band of frequencies received at an input node of the BAW resonator pass-band filter ladder to an output node of the BAW resonator pass-band filter ladder. A first rejection-band series resonator can be coupled in series between an input port of the BAW resonator pass-band filter ladder and the input node, the first rejection-band series resonator can have a first anti-resonant frequency peak in a rejection-band of frequencies that is less than the pass-band of frequencies. A second rejection-band series resonator can be coupled in series between an output port of the BAW resonator filter and the output node, the second rejection-band series resonator can have a second anti-resonant frequency peak in the rejection-band of frequencies.

An LC filter includes an input terminal, an output terminal, a multilayer body, plate electrodes, connection electrodes connecting the plate electrodes, capacitor electrodes, and a inductor vias. Each of the capacitor electrodes opposes the plate electrode. One end of an inductor via is connected with the input terminal with a capacitor electrode interposed therebetween. Another end of the inductor via is connected to an intermediate point of a connection electrode. An inductor via is connected between the plate electrode and a capacitor electrode. An inductor via is connected between the plate electrode and a capacitor electrode. One end of an inductor via is connected with the output terminal with a capacitor electrode interposed therebetween. Another end of the inductor via is connected to an intermediate point of a connection electrode.

A filter device includes an input terminal, an output terminal, a main body, a common electrode provided to the main body, a ground terminal, and LC parallel resonators connected to the common electrode and the ground terminal. Each LC parallel resonator includes a capacitor, a first via, and a second via. One end of the first via is connected to the common electrode, and another end thereof is connected to the ground terminal through the capacitor. One end of the second via is connected to the common electrode, and another end thereof is connected to the ground terminal without through the capacitor. The second via is connected between portions of the common electrode to which the first vias of two adjacent resonators are connected.

An electromagnetic wave shielding filter is configured in a magnetic field transmission scheme, not in a low pass filter or band pass filter scheme, and thus allows a desired signal to pass, while maintaining unintended electromagnetic waves shielded.

The present embodiment relates to an electromagnetic wave shielding filter for high-frequency communication, having a structure in which an elliptical ferrite magnetic core is formed inside the filter, a primary coil and a secondary coil are installed at both ends of the magnetic core, and then a shielding and penetration unit is formed of a shielding material on the elliptical magnetic field core, so that a signal from the primary coil is transmitted in the form of a magnetic field to the secondary coil, and the other unintended common-mode components are eliminated.

Disclosed is a device for filtering electrical noise in a vehicle. The device includes a housing connectable to the vehicle, a variable capacitor, an input signal line coupled to the variable capacitor and couplable to a first conductor that carries electrical signals along with electrical noise of a given amplitude, and an output signal line coupled to the variable capacitor and couplable to a second conductor. When the input signal line is coupled to the first conductor and the output signal line is coupled to the second conductor, the second conductor carries the electrical signals along with electrical noise of reduced amplitude within a range of frequencies. The device also includes a tuner coupled to the housing and configured to adjust a capacitance of the variable capacitor, wherein adjusting the capacitance of the variable capacitor adjusts the range of frequencies.

A filter for an electric machine is disclosed. The filter has an inductor, which is a coil, and a capacitor. The coil has multiple windings, and each turn of the windings includes at least one conductor which is designed to be flat. By virtue of the flat conductor of the coil, the capacitance of the filter is thus formed in the coil itself In the process, the surface of one conductor is arranged opposite the surface of an adjacent conductor.