Abstract: The invention relates to an arrangement for radio frequency signals particularly in a duplex filter summing part comprising a conductive housing and at least one common transmission line for at least two different signals. In order to reduce intermodulation distortion of signals, which arises in the summing part, the housing of the summing part is arranged to function as a ground plane for the transmission line without the ground plane of a printed board or a ground plane otherwise connected to the transmission line.

Abstract: A summing network for combining and feeding radio frequency signals supplied by radio transmitters to common antenna means, includes conductors, connectors and a stub. In order to make the tuning of the summing network easier, the stub includes a changer for changing the electrical length of the summing network as a response to a control signal fed to the stub.

Abstract: A temperature-compensated combiner including a control rod disposed in a combiner housing for controlling a middle frequency; a resonator tube secured to the housing and coaxially disposed around the control rod; a regulating cup arranged at an end of the control rod which faces the housing; a motor which controls the middle frequency and which is arranged at one end of the control rod; and a temperature-compensating tube for compensating for longitudinal changes exhibited by a unit including the control rod, the resonator tube and the regulating cup for changes in temperature. The temperature-compensating tube is positioned within the resonator tube and secured to that end of the resonator tube which faces the housing and to the frame of the motor.

Abstract: The invention relates to a comb-line high-frequency filter or the like, comprising an elongated casing (1) of an electrically conductive material, conductor rods of an electrically conductive material being arranged in a sequence at predetermined intervals in a substantially integral air cavity within the casing, one end of each conductor rod being short-circuited to the casing and its other end being detached therefrom so that each conductor rod forms with the casing (1) an air-insulated coaxial resonator. In each coaxial resonator, the ratio between the diameters (X, Y) of the casing (1) and the resonator (3) is within the range from about 2.8 to 3.3.

Abstract: A high-frequency bandpass filter, including several cylindrical conductor rods (3, 4) arranged in a line with predetermined spacings in a continuous space defined by an elongated housing (1) made of an electrically conductive material and closed on all sides, each conductor rod being attached and short-circuited at its first end to the housing (1) and spaced apart from the housing at its second end so that each conductor rod forms a coaxial resonator together with the housing. The second end of each conductor rod includes a portion (4) larger in diameter as compared with the remaining portion of the conductor rod, and the type of a coupling between two adjacent coaxial resonators is arranged to be set to be predominantly capacitive or predominantly inductive by adjusting the ratio of the distance between the first ends of the conductor rods (3, 4) of the coaxial resonators to a distance between the portions (4) with a larger diameter.