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.

A 5.sup.th generation (5G) or pre-5G communication system for supporting a higher data transfer rate than 4.sup.th generation (4G) communication systems such as long term evolution (LTE). An apparatus for radiating a signal in a wireless communication system may include: a power amplifier; an antenna; and a combine filter unit configured to transfer an output signal of the power amplifier to the antenna. The combine filter unit may include: a first impedance matching circuit; a second impedance matching circuit; and a plurality of filters coupled in parallel between the first impedance matching circuit and the second impedance matching circuit. Allowable power of each of the plurality of filters may be lower than a maximum and/or predetermined power output of the power amplifier.

Embodiments provide a filtering device, to effectively simplify assembly and tuning processes. The filtering device includes: a housing, including an inner cavity; a resonant conductor, having a resonance function, and disposed inside the inner cavity; and a pressing element, having one end disposed on the housing and another end suspended, and facing a position of an open-circuit end of the resonant conductor. A distance between the pressing element and the resonant conductor is changeable when the pressing element is pressed or drawn to adjust a resonant frequency. The filtering device provided in various embodiments is applicable to a plurality of communications devices for selecting a signal frequency.

Embodiments of the present invention provide an electrical filter structure having a direct-coupled-stub filter (DCSF). The lengths of the transmission line portions can be arranged such that electrical lengths of the transmission line portions are shorter, by at least 10 percent, than a fourth of a wavelength of a signal having a frequency of a passband center frequency of the electrical filter structure. Moreover, lengths of the stubs can be selected so that the electrical lengths of the stubs are longer, by at least 2%, than a fourth of a wavelength of a signal having a frequency of a passband center frequency of the electrical filter structure. The filter structures of embodiments of the present invention can advantageously improve filter characteristics without changing the topological structure of the filter.

A radio frequency power amplifier and a device are disclosed. A first microstrip line and a second microstrip line are coupled, one end of the second microstrip line is an open stub and another end of the second microstrip line is grounded; and the first microstrip line having a first width is connected to a first transmission line having a second width which is wider than the first width. Therefore, some harmonic bands suppression can be implemented independently. Furthermore, the harmonic termination is independent and may not impact one or more fundamental components during matching a network. In addition, it may not take up more space and is sufficiently compact. Furthermore, sufficient wide harmonic response bandwidth can be provided.

Protecting qubits of a quantum processor from spontaneous emission and thermal photon noise includes connecting a first port of a filter to a signal line of a readout resonator of a qubit circuit of a quantum processor. The filter has a passband including a readout resonator frequency associated with the readout resonator and a first stopband including a qubit transition frequency associated with the qubit circuit. A second port of the filter is connected to a measurement device. a signal line of the filter is galvanically connected to a reference ground in thermal contact to a stage of a cryostat. The galvanic connection further makes a thermal connection to an input signal line of the qubit circuit.

The disclosure relates to a 5.sup.th generation (5G) or pre-5G communication system for supporting a higher data transfer rate than a 4.sup.th generation (4G) communication system, such as long-term evolution (LTE). An antenna module is provided. The antenna module includes a filter for filtering a radio frequency (RF) signal, and a sub printed circuit board (PCB), the sub-PCB comprises a passive circuit for processing the RF signal, and, the sub-PCB may be coupled to the filter such that the filter operates as a bumper when being coupled to a filter board.

A filter circuit includes a branch line coupler and a balun circuit having an input terminal connected to the branch line coupler to receive a signal, a first line connected to the input terminal and having a length comparable to a quarter of an electrical length of one wavelength at a frequency of the signal, a second line connected to the input terminal and having a length comparable to the quarter, a third line connected to the second line and having a length comparable to the quarter, and a fourth line connected to the third line and electromagnetically coupled to the first line, the fourth line having a length comparable to the quarter, wherein an end of the first line and an end of the fourth line are both connected to a ground or open-circuited, or are connected to two respective terminating resistors whose resistance values are equal.

A superconducting device is described wherein the device comprises a substrate; a capacitor structure (604) and a superconducting inductor structure (602) disposed on the substrate, the capacitor structure an the superconducting inductor structure forming a superconducting microwave filter structure, in particular a low-pass filter, the superconducting inductor structure including a plurality of nanowires of a superconducting material, each of the plurality of nanowires being galvanically connected to one of a plurality of capacitor electrodes (608) forming the capacitor structure, wherein the cross-sectional dimensions of the plurality of nanowires are selected such that the kinetic inductance of each of the one or more nanowires is larger, preferably substantially larger, than the geometrical inductance of the nanowire.

A high-frequency module with a simple configuration and facilitates size reduction and mass production is provided. An oscillator that includes a bipolar transistor, an antenna, and mixers are realized as one circuit. A base of the bipolar transistor is electrically connected to a resonance pattern or the like that outputs a signal at a frequency in a quasi-millimeter wave band or higher by direct oscillation. A collector is electrically connected to a transmission line or the like which is connected to a power source. An emitter is electrically connected to a planar open transmission line or the like that operates as an antenna. A portion of the signal transmitted through the open transmission line is fed back to the base via a capacitance between the open transmission line and the base. The open transmission line is electrically connected to two diodes and each of which operates as a mixer.