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: The antenna device of the present invention is intended for a portable equipment for transmitting and/or receiving radio signals. Said antenna device comprises a helical antenna substantially having the characteristics of a half-wave antenna, a half-wave antenna, and an impedance transformer. Said helical antenna, said half-wave antenna, and said impedance transformer are intercouplable so that either said helical antenna alone is coupled to said impedance transformer or said helical antenna and said half-wave antenna are coupled in parallel to said impedance transformer in order to form two different working functions.

Abstract: An antenna device for a piece of equipment for transmitting and/or receiving radio signals, wherein the antenna device comprises a first extendable antenna (2), which is movable between an extended position, where it is coupled to the circuitry of the piece of equipment and a retracted position where it is not coupled to the circuitry, the extendable antenna (2) on its lower portion having first holding device (10) cooperating with a second holding device (9) arranged on a guide (5) for the first antenna such that the first antenna is releasably locked in the extended position. According to the invention the first antenna (2) is releasably locked by the first and second holding devices comprising mutually magnetically attractive elements (9,10).

Abstract: An antenna coupling device is disclosed for connecting, substantially inductively, a first antenna to a second antenna, whereat the antenna coupling device comprises a loop antenna (4) with two poles (15, 16). The loop antenna (4) is arranged to surround the first antenna and is connected to the second antenna via both of its poles (15, 16). Such an antenna coupling device connected via a cable (5) to an external antenna by the action of threading the antenna coupling device onto a helical antenna (2) of a hand-portable telephone (1) is used inside a vehicle for improving transmission and reception conditions of the hand-portable telephone (1).

Abstract: An improved antenna device for small size portable communication equipment comprising circuits (23) for transmitting and/or receiving radio signals as well as a chassis (25) and a feeding point (22) providing the electrical coupling of the antenna device to the communication equipment. The antenna device comprises a hollow helical antenna (6) fixed externally on the chassis and an antenna rod slidable through the helical antenna and being part of a straight radiator (1). The helical antenna (6) is of quarter-wave type and is coupled constantly via the feeding point (22) to the circuits (23).

Abstract: A known mounting for attaching an antenna pole to a motor vehicle window comprises an antenna mounting plate which is fitted to the outside of the window glass and an inner plate which is fitted to the inside of the window glass. The inner plate includes an antenna connector and a connector for connecting a coaxial cable to a receiver/transmitter. With the intention of simplifying the antenna mounting in a manner which will enable the antenna pole to be readily removed but nevertheless to be securely held when the vehicle is in use, and also with intention of eliminating the deleterious effect of atmospheric conditions on the mounting and the component parts thereof, so as to prevent corrosion or rusting, the mounting plate is made of an electrically non-conductive material and has formed integrally therewith an attachment which coacts slidable with an antenna-carrying attachment piece.

Abstract: An antenna is mounted on a window of a vehicle and includes an antenna rod (6) fastened to an electrically conductive base (1) mounted on the outside of the window, and a connection member on the inside of the window directly opposite the base. An antenna lead from the vehicle's radio is connected to the connection member, which comprises a box (8) with an earth plane and is mounted on the window with a conductive plate (12). A connection conductor (13) between the plate (12) and the antenna lead (15) has an electrical length of (1/4+n.times.1/2) times the wavelength of operation, where n=0 or a whole number. The surface exposed by the conductor (13) is spaced from the earth plane (16) so as to define a characteristic impedance for the conductor (13), so that the impedance at the antenna feed point together with the capacitive coupling through the window is transformed into an impedance equal to that of the antenna lead.

Abstract: Method and apparatus in mobile telephone system including base stations with a plurality of resonance modules, for separately adjusting each resonance module to its own frequency for receiving and expediting telephone signals at this frequency. In each resonance module, tuning is controlled to its given resonance position in relation to the frequency of the incoming signal, by an electromechanical drive which is connected for obtaining drive voltage by phase comparison. The drive voltage passes solely when two input signals differ in phase. When both signals are in phase, the drive voltage is zero, the drive then being stationary and the resonance module being adjusted in resonance to the input signal.

Abstract: An arrangement in tuning resonance modules includes a cavity and resonance body, which is steered to resonance position by a motor, which is driven by a voltage as long as there is a phase difference between the input signal to the resonance module and the output signal (called the measuring signal) from the module. The input signal is of high frequency, and it is desired now to transpose the signals down to low frequency for preventing interference with the measuring signal. The arrangement therefore includes a high-frequency oscillator controlled by a voltage and having a frequency range within which lies the frequency of the incoming signal. From the oscillator output signal and the input signal there is formed in a mixing means the difference between the signals, and in a second mixing means there is formed the difference between the oscillator output signal and the measuring signal such as to form hereby two low-frequency signals. These are compared in a phase detector with respect to phase position.