A low pass filter includes a first input/output terminal, a second input/output terminal, a signal line, inductors connected in the signal line, and capacitors connected between the signal line and ground. In the signal line, a capacitor is connected in parallel to the inductor that is connected closest to the first input/output terminal, and the inductor and the capacitor define a first parallel resonator.

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 filter circuit (1) includes a first transmission line (11), a second transmission line (12) which has an electrical length set to ½ of an electrical length of the first transmission line, a first capacitor (21), a second capacitor (22), and a third capacitor (23). Capacitances of the first capacitor, the second capacitor, and the third capacitor are set in such a manner that a circuit including the first transmission line, the second transmission line, and the first capacitor resonates in series at a predetermined fundamental frequency, a circuit including the first transmission line, the first capacitor, and the second capacitor resonates in parallel at a third harmonic frequency being a tripled frequency of the fundamental frequency, and a circuit including the second transmission line and the third capacitor resonates in series at the third harmonic frequency.

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.

A dual-band transform circuit structure includes a first transmission line, a second transmission line, and a conductive layer. The first transmission line has a first input terminal, a first output terminal, and a second output terminal. The second transmission line has a second input terminal, a third input terminal, a third output terminal, and a fourth output terminal. The second input terminal is coupled to the first output terminal, and the third input terminal is coupled to the second output terminal. The conductive layer is stacked with the first transmission and the second transmission line. The conductive layer includes a first hollow pattern. The first hollow pattern and the second transmission line are overlapped in a top view.

A ceramic waveguide filter, a radio unit, an antenna unit and a base station are disclosed. According to an embodiment, a ceramic waveguide filter comprises a body (1) that is made of a ceramic material and that has a plurality of resonators each including a blind hole (101). The blind holes (101) of two of the resonators open at a first surface of the body (1) and extend toward an opposite econd surface of the body (1). Capacitive coupling between the two resonators is achieved by a coupling structure (201) on/in a substrate (2), to which the body (1) is attached at the side of the second surface.

A ceramic waveguide filter, a radio unit, an antenna unit and a base station are disclosed. According to an embodiment, a ceramic waveguide filter comprises a body (1) that is made of a ceramic material and that has a plurality of resonators each including a blind hole (101). The blind holes (101) of two of the resonators open at a first surface of the body (1) and extend toward an opposite econd surface of the body (1). Capacitive coupling between the two resonators is achieved by a coupling structure (201) on/in a substrate (2), to which the body (1) is attached at the side of the second surface.

A transformer filter arrangement including a transformer having a first winding and a second winding is provided. Both of the first and the second windings are located between an outer border and an inner border, which is inside the outer border. The transformer filter arrangement further includes at least one reactive sub circuit, each including at least one inductor. The first winding of the transformer is divided into a plurality of winding segments. At least a first one of the at least one reactive sub circuit being connected in series with the winding segments of the first winding between two such winding segments, and having at least one of the at least one inductor located inside said inner border.

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 wireless communication module includes a wireless module board including an antenna, a frequency converter mounted on the wireless module board and configured to change a frequency of a wireless signal, an amplifier phase shifter mounted on the wireless module board and configured to change a phase and an intensity of the wireless signal, a band-pass filter mounted on the wireless module board so as to be provided between the frequency converter and the amplifier phase shifter, and a band-rejection filter formed on the wireless module board and composed of at least a portion of a plurality of wiring layers electrically connecting the frequency converter, the amplifier phase shifter, and the band-pass filter to each other.