Abstract: An arrangement for filtering the transmitting signals in a radio device using frequency division duplex. In a radio transmitter, in which the transmitting signal is divided to a plurality of antennas radiating to different sectors, the filtering required in transmitting is mostly carried out by a shared transmitting filter before the transmitting signal is divided. The rest of the filtering is carried out separately on each partial transmitting signal in the reduced transmitting side of the duplex filter. The filters and the divider form an integrated filter unit, in which they are connected to each other by simple coupling elements. The space required for the filters of the antenna end of the radio device is significantly reduced, and the material and assembly costs of the antenna end in production are reduced.

Abstract: An arrangement for filtering the transmitting signals in a radio device using frequency division duplex. In a radio transmitter, in which the transmitting signal is divided to a plurality of antennas (ANT1, ANT2, ANT3) radiating to different sectors, the filtering required in transmitting is mostly carried out by a shared transmitting filter (240) before the transmitting signal is divided. The rest of the filtering is carried out separately on each partial transmitting signal (T1; T2; T3) in the reduced transmitting side (TXF1; TXF2; TXF3) of the duplex filter. The filters and the divider (250) preferably form an integrated filter unit, in which they are connected to each other by simple coupling elements. The space required by the filters of the antenna end of the radio device is significantly reduced, and the material and assembly costs of the antenna end in production are reduced.

Abstract: A band stop filter comprises a transmission line with center and outer conductors, and coaxial resonators. The outer conductor forming a unitary conductive housing with an inner space divided by conductive partition walls into resonator cavities. Each of the resonator cavities contains at least one of the coaxial resonators, wherein each of the coaxial resonators separately has an electromagnetic coupling to the transmission line. The coupling arranged by a coupling element to form an attenuation peak in the a response curve of the filter, where the natural frequencies of the coaxial resonators differ from each other to shape the response curve of the filter. The transmission conductor is located inside the housing, running through openings in the partition walls across all the resonator cavities. The housing is the outer conductor of the transmission line, and a portion of the transmission conductor in a resonator cavity is the coupling element.

Abstract: A band stop filter (300) implemented by coaxial resonators for filtering antenna signals particularly in base stations of mobile communication networks. The starting point is a structure with a transmitting line and coaxial resonators electromagnetically coupled parallel with it, the natural frequencies of which resonators differ from each other slightly. The resonators (R1, R2, R3) form a unitary conductive resonator housing (310), the inner space of which has been divided into resonator cavities by conductive partition walls. In the invention, the center conductor (321) of the transmitting line is placed inside the resonator housing so that it runs across all the resonator cavities, and the housing functions as the outer conductor of the transmitting line at the same time. The resonator cavities are thus a part of the cavity of the transmitting line.

Abstract: The invention relates to a tunable resonator filter. In each resonator cavity of the filter there is a movable dielectric tuning element (728; 748) to adjust the resonator's natural frequency. The tuning elements are advantageously arranged to be moved by a common control implemented by a rod (708) joining them together, to shift the filter's band through equal displacements of the natural frequencies of the resonators. When the tuning element is moved horizontally sidewards from the resonator (710; 720; 730; 740; 750; 760) axis, the electrical length and natural frequency of the resonator change. In that case, when sub-bands are used it is not necessary to tune the filters separately for each sub-band in the stage of manufacture, as the sub-band can be chosen when the filter is put into use. The tuning elements can be movable also in each resonator separately, to implement the basic tuning in connection with the manufacture of the filter.

Abstract: The invention relates to a tunable resonator filter. In each resonator cavity of the filter there is a movable dielectric tuning element (728; 748) to adjust the resonator's natural frequency. The tuning elements are advantageously arranged to be moved by a common control implemented by a rod (708) joining them together, to shift the filter's band through equal displacements of the natural frequencies of the resonators. When the tuning element is moved horizontally sidewards from the resonator (710; 720; 730; 740; 750; 760) axis, the electrical length and natural frequency of the resonator change. In that case, when sub-bands are used it is not necessary to tune the filters separately for each sub-band in the stage of manufacture, as the sub-band can be chosen when the filter is put into use. The tuning elements can be movable also in each resonator separately, to implement the basic tuning in connection with the manufacture of the filter.

Abstract: The invention relates to a tunable resonator filter. In each resonator cavity of the filter there is a movable dielectric tuning element (728; 748) to adjust the resonator's natural frequency. The tuning elements are advantageously arranged to be moved by a common control implemented by a rod (708) joining them together, to shift the filter's band through equal displacements of the natural frequencies of the resonators. When the tuning element is moved horizontally sidewards from the resonator (710; 720; 730; 740; 750; 760) axis, the electrical length and natural frequency of the resonator change. In that case, when sub-bands are used it is not necessary to tune the filters separately for each sub-band in the stage of manufacture, as the sub-band can be chosen when the filter is put into use. The tuning elements can be movable also in each resonator separately, to implement the basic tuning in connection with the manufacture of the filter.

Abstract: The invention relates to a tunable resonator filter. In each resonator cavity of the filter there is a movable dielectric tuning element (728; 748) to adjust the resonator's natural frequency. The tuning elements are advantageously arranged to be moved by a common control implemented by a rod (708) joining them together, to shift the filter's band through equal displacements of the natural frequencies of the resonators. When the tuning element is moved horizontally sidewards from the resonator (710; 720; 730; 740; 750; 760) axis, the electrical length and natural frequency of the resonator change. In that case, when sub-bands are used it is not necessary to tune the filters separately for each sub-band in the stage of manufacture, as the sub-band can be chosen when the filter is put into use. The tuning elements can be movable also in each resonator separately, to implement the basic tuning in connection with the manufacture of the filter.

Abstract: A resonator or a filter consisting of resonators comprises an inner conductor or conductors and an outer conductor enclosing the inner conductor or conductors. It comprises a first part (201, 301, 401, 604, 701) and a second part (202, 302, 420, 501, 605, 702), of which the first part comprises at least a part of the inner conductor or conductors (203, 303, 402, 404, 703, 704, 705, 706, 707) and a part of the outer conductor (204, 205, 304, 305, 405, 406, 407, 408, 409), which is integral with the inner conductor parts and made of the same material, and of which the second part comprises such a part of the outer conductor (206, 207, 304, 305, 421, 422, 423, 424, 425) which, when connected to the first part, forms a continuous outer conductor enclosing the inner conductor.

Abstract: A radio frequency filter has a band-pass type frequency response which is controllable in a manner such that the frequency response may be moved between the transmission frequency (TX') and reception frequency (RX') of associated radio equipment. Thus the radio frequency filter may be used both as a transmission filter and as receiving filter, provided that the transmission and reception take place at different times. The radio frequency filter includes a change-over switch, which connects the radio frequency filter to a transmitter when the pass band of the radio frequency filter is in the transmission frequency, and which connects to the receiver when the pass band of the radio frequency filter is in the reception frequency.

Abstract: A dielectric filter advantageously comprises a body of a dielectric material rectangular in cross-section and confining at least two parallel holes (31', 32', 33') that extend through the body parallel to each other and parallel to the side surface (34) plane. Major portions of the body are coated with a conductive material which also covers the inner surfaces of the holes (31', 32', 33'), hence forming a transmission line resonator for each hole. The resonators may be quarter-wave or half-wave resonators. According to the invention, the holes are located on at least two lines in the long direction of the body in which case the center axis of at least one hole (32') is not located on the same plane parallel to the side surface (34) as the center axes of the rest of the holes. Advantageously, the distance (D) of the center axis of a hole from the center axis of an adjacent hole is identical for all holes.

Abstract: The present invention relates to a radio frequency filter, comprising a block(1) of a dielectric agent and an insulation sheet (2) attached to a side surface thereof. From the top surface of the block to the undersurface, at least two holes (3,4,5) coated with a conductive agent extend. At least most of the surface of the body, with the exception of one side surface, as well as the surfaces of the holes have been coated with a conductive agent, whereby a transmission line resonator is produced for each hole. The surface of the insulation sheet (2) fixed against the uncoated side surface but not facing the block has also been coated with a conductive agent. The coupling pattern formed by the metallic electrodes is located between the opposite surfaces. The unevenness of the surfaces placed against each other and the defects in adjusting the pieces cause great divergence in the response curves of the filters.

Abstract: A ceramic filter can be made small in size by forming one or more strip-line resonators (5) on a side surface (4) of the ceramic resonator, the side surface additionally having contact and coupling electrodes which can be formed using the same mask as for the strip-line resonators. The strip-line resonators (5) produce zeros in the transfer function of the filter and thereby increase the attenuation at a desired frequency, e.g. the image frequency.

Abstract: An adjustable resonator arrangement comprises a main resonator (T1) and a secondary resonator (T2) reactively coupled thereto. The secondary resonator includes a switching element (S), e.g. a varactor, having at least two states. When the switching element is in a first state the secondary resonator behaves as a half-wave resonator having a resonant frequency f.sub.o substantially different to the resonant frequency f of the main resonator. Consequently the secondary resonator has no appreciable affect on the resonant frequency of the main resonator. However, when the switching element is in a second state, the secondary resonator behaves as a quarter-wave resonator having a resonant frequency 2*f.sub.o which is closer to the inherent frequency f of the main resonator and sufficiently close to cause a shift .DELTA.f in the effective frequency of the main resonator.