Various substrate-integrated waveguide (SIW) filtering crossover systems are described. An example SIW filtering crossover system may include: a substrate; a top metal plate placed on top of the substrate; a bottom metal plate placed beneath the substrate; a plurality of metalized via-holes in the substrate connecting the top metal plate and the bottom metal plate; and a plurality of grounded-coplanar-waveguides (GCPWs) coupled to sidewalls of the crossover system, wherein each of the GCPWs connects the crossover system to a respective microstrip line for signal transmission between the respective microstrip line and the crossover system.

A harmonic trap filter suppresses at least one harmonic signal produced by an amplifier and includes an input terminal and a ground terminal. The harmonic trap filter further includes a plurality of resonators electrically coupled one to another between the input terminal and the ground terminal in a spatial order defined by relative phase shift of alternating voltage bias signals respectively applied thereto. The resonators are tuned to resonate at a frequency at which a phase delay is imparted to the at least one harmonic signal by the resonators to effect cancelation of the at least one harmonic signal at the input terminal.

A harmonic trap filter suppresses at least one harmonic signal produced by an amplifier and includes an input terminal and a ground terminal. The harmonic trap filter further includes a plurality of resonators electrically coupled one to another between the input terminal and the ground terminal in a spatial order defined by relative phase shift of alternating voltage bias signals respectively applied thereto. The resonators are tuned to resonate at a frequency at which a phase delay is imparted to the at least one harmonic signal by the resonators to effect cancelation of the at least one harmonic signal at the input terminal.

A dielectric filter, a duplexer, and a communications device are provided. The dielectric filter includes a dielectric body, and a wideband filtering structure and a narrowband filtering structure that are disposed in the dielectric body. The wideband filtering structure includes a groove disposed on a first surface of the dielectric body and configured to adjust a frequency position of a passband of the wideband filtering structure; and at least one first resonator including a through hole penetrating the bottom of the groove and a second surface of the dielectric body; and an open loop located on a bottom surface of the groove and is disposed around an opening of the through hole. The narrowband filtering structure includes at least one second resonator including a blind hole disposed on the second surface of the dielectric body. The first surface and the second surface of the dielectric body are disposed oppositely.

A dielectric filter, a duplexer, and a communications device are provided. The dielectric filter includes a dielectric body, and a wideband filtering structure and a narrowband filtering structure that are disposed in the dielectric body. The wideband filtering structure includes a groove disposed on a first surface of the dielectric body and configured to adjust a frequency position of a passband of the wideband filtering structure; and at least one first resonator including a through hole penetrating the bottom of the groove and a second surface of the dielectric body; and an open loop located on a bottom surface of the groove and is disposed around an opening of the through hole. The narrowband filtering structure includes at least one second resonator including a blind hole disposed on the second surface of the dielectric body. The first surface and the second surface of the dielectric body are disposed oppositely.

A circuit device that is connected to a temperature detection element that detects a temperature of an object via an external signal line and an external signal ground line includes a connector that is connected to the external signal line and the external signal ground line, an internal signal line that is connected to the external signal line via the connector, an internal signal ground line that is connected to the external signal ground line via the connector, a controlling circuit that is connected to the internal signal line and the internal signal ground line and detects the temperature of the object, and a high-frequency filter that is inserted into at least one of a foremost stage of the internal signal line and a foremost stage of the internal signal ground line as viewed from the connector.

A harmonic trap filter suppresses at least one harmonic signal produced by an amplifier and includes an input terminal and a ground terminal. The harmonic trap filter further includes a plurality of resonators electrically coupled one to another between the input terminal and the ground terminal in a spatial order defined by relative phase shift of alternating voltage bias signals respectively applied thereto. The resonators are tuned to resonate at a frequency at which a phase delay is imparted to the at least one harmonic signal by the resonators to effect cancelation of the at least one harmonic signal at the input terminal.

A harmonic trap filter suppresses at least one harmonic signal produced by an amplifier and includes an input terminal and a ground terminal. The harmonic trap filter further includes a plurality of resonators electrically coupled one to another between the input terminal and the ground terminal in a spatial order defined by relative phase shift of alternating voltage bias signals respectively applied thereto. The resonators are tuned to resonate at a frequency at which a phase delay is imparted to the at least one harmonic signal by the resonators to effect cancelation of the at least one harmonic signal at the input terminal.

A filter which stops the propagation of an electromagnetic wave of a predetermined frequency band in a signal line or a power supply line is provided. This filter is a conductor connected to the signal line or the power supply line. This conductor is configured to include a linear portion. The first portion of the linear portion with an end portion connected to the signal line or the power supply line has the first width, and the second portion different from the first portion of the linear portion has the second width different from the first width.

A filter which stops the propagation of an electromagnetic wave of a predetermined frequency band in a signal line or a power supply line is provided. This filter is a conductor connected to the signal line or the power supply line. This conductor is configured to include a linear portion. The first portion of the linear portion with an end portion connected to the signal line or the power supply line has the first width, and the second portion different from the first portion of the linear portion has the second width different from the first width.