A directional coupler includes a main line for transmitting a high frequency signal, a sub line electromagnetically coupled to the main line, a termination circuit for terminating one end portion of the sub line, and a variable filter that has an input terminal and an output terminal and the input terminal is connected to another end portion of the sub line. The variable filter is a filter unit circuit having one frequency band as a pass band or a stop band, and in the filter unit circuit, a variable passive element for shifting a frequency in the pass band or the stop band is disposed.

A directional coupler includes a main line for transmitting a high frequency signal, a sub line electromagnetically coupled to the main line, a termination circuit for terminating one end portion of the sub line, and a variable filter that has an input terminal and an output terminal and the input terminal is connected to another end portion of the sub line. The variable filter is a filter unit circuit having one frequency band as a pass band or a stop band, and in the filter unit circuit, a variable passive element for shifting a frequency in the pass band or the stop band is disposed.

A differential transmission line cable includes a notch filter to manage common-mode energy. The cable includes a narrow portion with two adjacent electrical conductors each having a narrow cross-sectional area and spaced at a narrow spacing. The cable also includes a wide portion longitudinally adjacent to the narrow portion. The wide portion includes the two adjacent electrical conductors each having a wide cross-sectional area greater than the narrow cross-sectional area and spaced at a wide spacing greater than the narrow spacing. The wide and narrow cross-sectional areas and spacings are specified so that the differential-mode impedance of the differential transmission line cable is uniform throughout both the narrow and wide portions and so that differences in the common-mode impedances of the narrow and wide portions create a notch filter to manage common-mode energy in the differential transmission line cable.

A differential transmission line cable includes a notch filter to manage common-mode energy. The cable includes a narrow portion with two adjacent electrical conductors each having a narrow cross-sectional area and spaced at a narrow spacing. The cable also includes a wide portion longitudinally adjacent to the narrow portion. The wide portion includes the two adjacent electrical conductors each having a wide cross-sectional area greater than the narrow cross-sectional area and spaced at a wide spacing greater than the narrow spacing. The wide and narrow cross-sectional areas and spacings are specified so that the differential-mode impedance of the differential transmission line cable is uniform throughout both the narrow and wide portions and so that differences in the common-mode impedances of the narrow and wide portions create a notch filter to manage common-mode energy in the differential transmission line cable.

A zeroing structure applicable to an adjustable diplexer includes a substrate, holder, motor, lead screw, displacement plate, stop element and interference element. The holder is disposed on the substrate. The motor is disposed on the holder. The lead screw is rotatably disposed on the holder and connected to the motor, and thus rotation of the lead screw is driven by the motor. The displacement plate is movably disposed on the substrate and helically connected to the lead screw so as to undergo linear motion between a first position and a second position relative to the substrate when guided and driven by the motor. The stop element is disposed on the lead screw. The interference element is disposed on the displacement plate and at the position that allows the interference element to come into contact with the stop element when the displacement plate is at the first position. The zeroing structure enables the adjustable diplexer operable at an adjustable center frequency to perform mechanical zeroing and enables primary or auxiliary confirmation of zeroing detection. Furthermore, the zeroing structure is highly reliable and incurs low cost.

A zeroing structure applicable to an adjustable diplexer includes a substrate, holder, motor, lead screw, displacement plate, stop element and interference element. The holder is disposed on the substrate. The motor is disposed on the holder. The lead screw is rotatably disposed on the holder and connected to the motor, and thus rotation of the lead screw is driven by the motor. The displacement plate is movably disposed on the substrate and helically connected to the lead screw so as to undergo linear motion between a first position and a second position relative to the substrate when guided and driven by the motor. The stop element is disposed on the lead screw. The interference element is disposed on the displacement plate and at the position that allows the interference element to come into contact with the stop element when the displacement plate is at the first position. The zeroing structure enables the adjustable diplexer operable at an adjustable center frequency to perform mechanical zeroing and enables primary or auxiliary confirmation of zeroing detection. Furthermore, the zeroing structure is highly reliable and incurs low cost.

The present disclosure provides a cavity filter assembly installed with an RF filter having an empty area formed between the RF filter and a cavity filter body serving as a ground to reduce the parasitic capacitance by forming the cavity filter body with a first pocket portion configured to install the RF filter and a second pocket portion within the first pocket portion in a position to overlap a transmission line, thereby reducing the insertion loss of the RF filter, which when serving as a low-pass filter, can position the harmonics in the stopband further away from the cutoff frequency and thus effect improved frequency characteristics of the low-pass filter through improvements of, for example, the frequency characteristics in the stopband.

A filter is provided, and the filter includes two mutually coupled slow-wave resonators. Each resonator includes a coplanar waveguide (CPW) transmission line, a tapered CPW transmission line, and a ground stub, and can generate a slow-wave feature to push a high-order harmonic wave of a baseband signal to a high frequency, so as to implement a wide stopband feature. In addition, a slow-wave effect is used to properly design a size of a filter, to reduce an entire area of the filter and reduce costs. Moreover, two resonators are coupled, to enhance passband performance of the filter, increase bandwidth, increase in-passband flatness, and reduce an insertion loss.

Composite substrate (1300; CS) for radio frequency, RF, signals comprising at least a first layer (1310; 1310a) of di-electric material and a second layer (1320; 1320a) of dielectric material, and at least one conductor layer (1330; 1330a) of an electrically conductive material arranged between said first layer (1310; 1310a) and said second layer (1320; 1320a), wherein said first layer (1310; 310a) and said second layer (1320; 1320a) and said conductor layer (1330; 1330a) each comprise optically transparent material.

A waveguide transition includes a ridge waveguide section with a first ridge part running along a first wall having a first distance to an opposing second wall. The waveguide transition comprises a partial H-plane waveguide section with an electrically conducting foil that comprises a longitudinally running foil slot ending a certain edge distance before a foil edge that faces the ridge waveguide section. The ridge waveguide section and the partial H-plane waveguide section overlap during a transition section that has a first end at a transition between the second wall and a third wall. There is a second distance between the first wall and the third wall that exceeds the first distance. The transition section has a second end where the first ridge part ends by a transversely running second ridge part that crosses the foil slot and connects to a third wall.