A radio frequency (RF) filter circuit for rejecting one or more spurious components of an input signal has a first resonator circuit including a first capacitor and a first coupled inductor pair of a first inductor and a second inductor, and a second resonator circuit with a second capacitor and a second coupled inductor pair of a third inductor and a fourth inductor. First and second resonator coupling capacitors are connected to the first resonator circuit and the second resonator circuit. A first port and a second port are connected to the first resonator circuit and the second resonator, with the filtered signal of the input signal passed through both the first resonator circuit and the second resonator circuit being output.

An electronic component includes first through sixth LC parallel resonators and seventh through ninth capacitors. The first through sixth LC parallel resonators are arranged in this order in a first direction perpendicular or substantially perpendicular to a stacking direction of a multilayer body of the electronic component, and define a band pass filter. The seventh capacitor is connected between the first and sixth LC parallel resonators. The eighth capacitor is connected between the first and third LC parallel resonators. The ninth capacitor is connected between the fourth and sixth LC parallel resonators.

Radio frequency (RF) filter structures and related methods and RF front-end circuitry are disclosed. In one embodiment, an RF filter structure includes a first terminal and a first tunable RF filter path defined between the first terminal and a second terminal. The first tunable RF filter path is tunable to provide impedance matching between the first terminal and the second terminal at a first frequency. The first frequency may be provided within a first frequency band. Additionally, the RF filter structure includes a second tunable RF filter path defined between the first terminal and the second terminal. The second tunable RF filter path is tunable to provide impedance matching between the first terminal and the second terminal at a second frequency. The second frequency may be within a second frequency band. In this manner, the RF filter structure is configured to provide impedance tuning for multiple impedance bands simultaneously.

A front-end circuit with a tunable filter is disclosed. In an embodiment, the front end circuit includes a first signal path connected to an antenna connection, a first filter arranged in the first signal path, wherein the first filter is tunable within a first frequency range, and an extra signal path and a first fixed filter arranged therein, wherein the first fixed filter has a passband for an extra frequency band, wherein the first fixed filter is not tunable, and wherein the extra frequency band is arranged outside or inside the first frequency range. The front end circuit further includes a narrowband antenna tuner configured to be set to a respective tunable frequency range, wherein the narrowband antenna tuner is arranged between the first filter, the first fixed filter and the antenna connection in the first and second signal paths.

Reflectionless low-pass, high-pass, band-pass, band-stop, all-pass, and all-stop filters, as well as a method for designing such filters is disclosed, along with a method of enhancing the performance of such filters through the use of sub-networks to further modify and improve the frequency response. These filters preferably function by absorbing the stop-band portion of the spectrum rather than reflecting it back to the source, which has significant advantages in many different applications. The sub-networks preferably offer additional degrees of freedom by which the leakage through the parent filter may be cancelled or reinforced to alter cutoff sharpness, stop-rejection, or other measures of performance.

A time delay filter comprising a substrate comprising a first surface and a second surface opposite the first surface; a first LC resonator coupled to the substrate and comprising a first coupling point, a first capacitive element electrically coupled between the first coupling point and the first conductive region, and a first inductive element coupled between the first coupling point and the first conductive region, and comprising a first and second inductor tap; and a second LC resonator coupled to the substrate and comprising a second coupling point, a second capacitive element electrically coupled between the second coupling point and the first conductive region, and a second inductive element electrically coupled between the second coupling point and the first conductive region wherein the system group delays a signal output at a second coupling point relative to a signal input at the first coupling point.

A time delay filter comprising a substrate; four coupled LC resonators, each having a coupling point; a first capacitor that electrically couples the first coupling point to the second coupling point; a second capacitor that electrically couples the second coupling point to the third coupling point; and a third capacitor that electrically couples the third coupling point to the fourth coupling point; the filter group delaying a signal output at the fourth coupling point relative to a signal input at the first coupling point.

Reflectionless low-pass, high-pass, band-pass, band-stop, all-pass, and all-stop filters, as well as a method for designing such filters is disclosed, along with a method of enhancing the performance of such filters through the use of sub-networks to further modify and improve the frequency response. These filters preferably function by absorbing the stop-band portion of the spectrum rather than reflecting it back to the source, which has significant advantages in many different applications. The sub-networks preferably offer additional degrees of freedom by which the leakage through the parent filter may be cancelled or reinforced to alter cutoff sharpness, stop-rejection, or other measures of performance.

The network filtering circuit includes a cable side for connection with a network cable, a physical side for connection with a mother board, and a plurality of transmission channels connected between the cable side and the physical side. Each of the transmission channels includes a first transmission line and a second transmission line with a CMC linked therebetween. Two filtering (Y type) capacitors are further linked between the first transmission line and the second transmission line with a middle line connected between the two filtering capacitors and having an extension line wherein in such an extension line there are a resistor and an optional adjusting capacitor to a ground node at the end in series connection

Provided is a high frequency module capable of reducing size and cost. A high frequency module includes an LC filter having an inductor formed through a thin film process and a capacitor also formed through a thin film process, and a piezoelectric resonator that is connected in series to the LC filter and serves as a trap filter having a resonant frequency at the outside of a passing band of the LC filter.