Abstract: The invention relates to a method and arrangement for positioning one or more mobile stations, in which the location of the mobile stations is determined in the horizontal direction using at least two radio direction finding stations. Information on the location of each mobile station is maintained on a server. The mobile station measures at least one variable proportional to the location of the mobile station in the vertical direction and signals information on the measurement results to a control unit time-divisionally at the same frequency controlled by the control unit. In the control unit the location of each mobile station is determined in the vertical direction on the basis of the signalled data and the data on the location is conveyed to the server, where the three-dimensional location of the mobile stations is determined. The locations of at least some of the mobile stations are displayed graphically.

Abstract: The invention relates to a method and arrangement for positioning one or more mobile stations, in which the location of the mobile stations is determined in the horizontal direction using at least two radio direction finding stations. Information on the location of each mobile station is maintained on a server. The mobile station measures at least one variable proportional to the location of the mobile station in the vertical direction and signals information on the measurement results to a control unit time-divisionally at the same frequency controlled by the control unit. In the control unit the location of each mobile station is determined in the vertical direction on the basis of the signalled data and the data on the location is conveyed to the server, where the three-dimensional location of the mobile stations is determined. The locations of at least some of the mobile stations are displayed graphically.

Abstract: The invention relates to a high-pass filter realized in a conductive casing by means of mechanical structural elements, which filter is suitable for signal processing especially at microwave frequencies. In the casing (201, 202, 203) there are in series rigid conductive elements (2IN, 210, 220, 230, 2OUT) separated from each other. Between successive elements there is capacitance that can be adjusted within certain limits, if necessary. The insulating material between the elements is air or plastic, for example. At least some of the conductive elements involve a conductor (214, 224) less than half a wavelength long, short-circuited at the opposite end to the casing. This together with the casing connected to the signal ground provides a transmission line which, looking from the conductive element, is inductive at the operating frequencies.

Abstract: The invention relates to a bandpass filter comprised of coaxial resonators. On the side of a resonator chain (200) which makes the filter there is provided an additional equalizing resonator (EQ1) which is coupled to a resonator (R3) in the chain. The resonance frequency of the equalizing resonator and the coupling with the rest of the filter are arranged so that attenuation increases at a point corresponding to an original attenuation minimum. Thereby it follows that attenuation variation in the whole pass band decreases. Response equalization can be further enhanced by providing a second equalizer (EQ2) affecting a band beside the first one. Using the structure according to the invention, a decrease of a certain magnitude in the pass band attenuation variation of a bandpass filter can be achieved with a smaller increase in the number of resonators than in known structures. Moreover, the production costs caused by the additional structure are relatively small.

Abstract: The invention relates to a high-pass filter realized in a conductive casing by means of mechanical structural elements, which filter is suitable for signal processing especially at microwave frequencies. In the casing (201, 202, 203) there are in series rigid conductive elements (2IN, 210, 220, 230, 2OUT) separated from each other. Between successive elements there is capacitance that can be adjusted within certain limits, if necessary. The insulating material between the elements is air or plastic, for example. At least some of the conductive elements involve a conductor (214, 224) less than half a wavelength long, short-circuited at the opposite end to the casing. This together with the casing connected to the signal ground provides a transmission line which, looking from the conductive element, is inductive at the operating frequencies.

Abstract: The invention relates to a bandpass filter comprised of coaxial resonators. On the side of a resonator chain (200) which makes the filter there is provided an additional equalizing resonator (EQ1) which is coupled to a resonator (R3) in the chain. The resonance frequency of the equalizing resonator and the coupling with the rest of the filter are arranged so that attenuation increases at a point corresponding to an original attenuation minimum. Thereby it follows that attenuation variation in the whole pass band decreases. Response equalization can be further enhanced by providing a second equalizer (EQ2) affecting a band beside the first one. Using the structure according to the invention, a decrease of a certain magnitude in the pass band attenuation variation of a bandpass filter can be achieved with a smaller increase in the number of resonators than in known structures. Moreover, the production costs caused by the additional structure are relatively small.