Abstract: A multi-band antenna for mounting on the housing of a hand-portable telephone, the antenna comprising a feed portion and an antenna whip, arranged to slide into and out of the telephone to retracted and extended positions and combined with a multi-band helical structure. There are alternative ways disclosed of arranging the helical structure and other possible radiating elements of the antenna means to attain operability within separated frequency bands, for example, at 900 and 1800 MHz. In some configuration, the antenna means requires an impedance matching circuit in order to be operable at different frequency bands.

Abstract: An antenna means to be mounted on a personal telephone is disclosed. The antenna means comprises a helical radiator, an elongated radiator extendable through the helical antenna, and a coupling means for activating the extendable elongated radiator, when in extended position. A more compact antenna means, with less need for receiving depth inside the telephone, is achieved by permitting the extendable elongated radiator, when in a retracted position, to extend at least partially inside the helical radiator. In the extended position the elongated radiator may be coupled to the telephone directly or via the helical antenna.

Abstract: An aperture-coupled antenna, comprising at least one antenna element including a number of substantially planar, mutually parallel radiating patches (1-3) being fed with microwave power from a feed network (6) via an aperture (5a, 5b) in a ground plane layer (4). The feed network (6) feeds microwave power in at least two separate frequency bands, including a first, relatively low frequency band and a second, relatively high frequency band. A first patch (2) radiates microwave power in the first frequency band and is provided with an aperture (9a, 9b) so as to couple microwave power in the second frequency band to a second patch (1), the microwave power in the second frequency band being fed from the feed network (6) via the apertures (5a, 5b; 9a, 9b) in the ground plane layer (4) and the first patch (2) to the second patch (1).

Abstract: A method and a system for tuning a resonance module in a radio base station is disclosed. The resonance module has tuning means, a transmitter connection, and an antenna connection. High-frequency input and output signals on the transmitter and antenna connection, respectively, are sensed and processed to tune the resonance module to a frequency of the input signal on the transmitter connection. The processing of the sensed input and output signals includes processing in a low-frequency range. Prior art methods are improved by the invention through the use of a quadrature modulator to increase adjustment speed and overall applicability of the resonance module to be tuned.

Abstract: The invention relates to a broadband antenna having a first and a second helical antenna (203, 207) wherein the antennas (203, 207) have different resonance frequencies. An antenna which has essentially a larger bandwidth than the bandwidth of an individual helical antenna is formed in coaction between the helical antennas (203, 207), by arranging the antennas coaxially and in generally the same axial positions, wherein the helical antennas (203, 207) are separated galvanically, possibly with the exception of at respective supply points. When fitted to portable equipment, the helical antennas (203, 207) can be combined with an axially movable straight wire antenna.

Abstract: A method and device for measuring the return loss of a radiofrequency signal at a feeding circuit coupled to a load, wherein the forward power and the reflected power are sensed by a measuring circuit having first and second branches (11, 12) for transferring a derived forward signal and a derived reflected signal, respectively. The return loss is calculated on the basis of the sensed power levels (P1, P2) of the derived signals in the first and second branches. The sensing range of power levels (P2) to be sensed in one branch (12) is adjusted in response to the sensed power level (P1) in the other branch (11), whereby the dynamic range required for power sensing in the measuring circuit is reduced.

Abstract: An elongated antenna, especially an omnidirectional antenna, has a vertical, elongated rod-like structure with two metal profile elements (10, 20) provided with dipole elements (2) as integral parts thereof. The rod-like structure (1) is surrounded by a tube (3). The antenna elements (2) are coupled in parallel to a single transmission coaxial cable (8). The antenna has a high gain and low losses.

Abstract: A substantially flat, aperture-coupled antenna element of the kind comprising a multilayer structure with a radiating patch (2) arranged on a dielectric layer (1), an electrically conductive ground plane layer (3) having a cross-shaped aperture (4) with two crossing slots (4a, 4b) being centered in relation to the patch, and a dielectric board provided with a feed network (6) for feeding microwave energy via feed elements (7, 8) and said cross-shaped aperture (4) to said patch so as to cause the latter to generate a dual polarized microwave beam propagating from the antenna element.

Abstract: A flat aperture-coupled antenna with a multilayer structure is disclosed. A rear side of the antenna comprises a metal reflector device including a hollow structure (3, 5) with separate box-like compartments, located in registry with radiating patches, corresponding pairs of orthogonal slots and feed elements, whereby microwave propagation within the hollow metal structure is substantially interrupted and any mutual coupling between the orthogonal slots is avoided.

Abstract: A method and device for monitoring a mobile telephone repeater are disclosed. The repeater is of the kind comprising an uplink (100) and a downlink (200) between two antennas (1, 2), wherein the repeater receives, amplifies and retransmits signals between a base station and a mobile telephone. A stability test is performed automatically, whereby a possible continuous and strong signal, being caused either by an instability involving a positive feedback between the two antennas or by a disturbing signal, is detected, whereupon the amplifying gain is adjusted in response to the result of the stability test. The test criterion includes the step of checking whether the level of the input signal in the respective amplifier chain exceeds a threshold value during at least a major portion of a measuring period.

Abstract: Antenna devices, including a pair and larger arrays of radiators, wherein each pair is to be connected to a first transmission line having a first characteristic impedance Z1. Each pair includes at least first and second radiating elements (1, 2) and first and second impedance transformers (3, 4) for the first and second radiating elements. One side of each transformer is connected to the respective element. The other sides are inter-connected by a second transmission line (8) to which their impedances are matched. The second transmission line has a resistive first impedance R1 equal to twice the first characteristic impedance Z1. The first transmission line is to be connected to the second transmission line at a selected one of many possible contact points (9). The selected contact point then determines a signal phase difference between said first and second radiating elements.

Abstract: A TM mode dielectric resonator and a filter comprising such a resonator. The resonator includes metallic walls defining a cavity. A dielectric resonator body is accommodated within the cavity. An end surface of the dielectric resonator body is located in the vicinity of one cavity wall, so as to provide a spacing between said end surface and said cavity wall, at least in a region corresponding to a portion of said end surface. The spacing can be obtained by washers, arranged between the dielectric resonator body and said cavity wall. It can also be obtained by means of a recess in said cavity wall, one or more protrusions on said cavity wall, or a metallic or dielectric ring arranged between the dielectric resonator body and said cavity wall.

Abstract: An compact antenna device which is intended for a small-size portable radio communication device and comprises a ground plane (1), a first radiating patch (2), a grounding means (3) connecting the patch and the ground plane. The patch is fed by a feeding means (6) which is situated on the same or opposite side of the ground plane or coplanar therewith and couples through a slot (5) provided in the ground plane. The disclosed antenna device may include further radiating patches in the same or higher levels as the first radiating patch. The antenna device also provides for wideband and/or multiband operation.

Abstract: An antenna system for a radio communication device, in particular a hand-portable telephone, having communication circuits and to be operating by circularly-polarized radio waves. In the system (1) there is provided a radiation means, preferably helical elements (2, 3, 4), a feeding network (8) having first coupling means (9) adapted for coupling to said communication circuits and second coupling means coupled to said helical elements (2, 3, 4). The interface means includes a closed resonator means (14), which has at least a first portion associated with said first coupling means (9), and having separated at least second (11), third (12) and fourth (13) portions forming said second coupling means (11, 12, 13).

Abstract: A mobile telephone repeater with a variable bandwidth is disclosed. The repeater comprises an uplink and downlink, each being provided with amplifier chains (6). Each chain comprises at least two band pass filter units (10, 11) coupled in series and having controllable pass bands, which at least partially overlap each other. The center frequency of the filter units are controllable so as to make the bandwidth of the resulting pass band variable. Consequently, the effective bandwidth of the amplifier chain is controllable.

Abstract: An antenna device is disclosed, which is intended for a portable radio communication device, in particular a pocket size cellular telephone. The novel antenna device includes a housing (1) having mounting means (2) for mounting on the telephone (3), helically configured first radiator (4) carried by the housing, and an impedance matching means (6) formed by reactive components on a dielectric substrate provided with a printed circuit pattern. The matching means is carried by the housing and it matches an impedance of the first radiator to an impedance of transceiver circuitry of the telephone. The antenna device may include one or more radiators in addition to the first radiator. The disclosed antenna means is particularly advantageous when the antenna device includes at least one radiator of half-wave type.

Abstract: A feed line structure (1), especially integrated with a stationary array of antenna elements so as to enable adjustment of the direction of the beam radiated from the array. The feed line structure comprises a feed conductor line pattern (3) disposed on a fixed carrier plate (2) at a distance from and in parallel to a fixed ground plate (4), and a movable dielectric plate (5) located therebetween. The feed line pattern (3) is elongated in the same direction (A) as the movement direction of the dielectric plate (5). The propagation velocity of the signal components is reduced by the dielectric plate (5), whereby a controlled phase difference between the various signal components is obtained.

Abstract: The invention relates to a system for the supervising of a receiving antenna, the system comprising partly a first sensor for the sensing of an incoming electrical signal from the receiving antenna to the first sensor, a signal processing circuit with an interface, the first sensor being permanently connected between the receiving antenna and receiving circuits and the sensing being carried out at any moment without changing the mutual connection configuration of the receiving antenna and the receiving circuits. The system is provided with a test transmitter connected to the receiving antenna via a coupling circuit and in front of a second sensor, which is permanently connected between the receiving antenna and the receiving circuits, the second sensor being arranged for the sensing of an outgoing electrical signal to the receiving antenna and the signal processing circuit being arranged to deliver, via the interface, an indication of the operability of the receiving antenna based on the sensing.

Abstract: A bypass device in a low noise amplifier unit for amplifying communication signals in the microwave frequency range. The device includes a printed circuit board with transmission lines (1, 2), an amplifier (A), a transmission line bypass segment (3) extending in parallel to the amplifier, and switching means for activating said bypass segment in case the amplifier becomes inoperable. The amplifier is connected between two transmission line stub segments (4, 5).

Abstract: An improved repeater for receiving and re-transmitting radio signals for a cell in a cellular telecommunication system. The repeater raises the levels and is capable of converting the frequencies of the radio signals used in the telecommunication system. Due to the power amplifiers being provided between the channel selecting means and combiner, the power amplifier needs only to amplify one frequency band. In this way the repeater gets a simpler design, demands less maintenance, and gets a higher degree of efficiency in combination of high power capacity and generation of low levels only of intermodulation products.