Abstract: A radiotelephone system for motor vehicles, having a group antenna system with a plurality of antenna elements, and a mobile radiotelephone with a high-frequency input for receiving radio signals. The group antenna system contains controllable phase and/or amplitude adjusting elements, which are set so that a directed reception with a main receiving direction is available. The controllable phase and/or amplitude adjusting elements are controlled by a processor for tracking the main receiving direction azimuthally in the direction of a fixed station with the help of a tracking signal. Controllable switching-elements for reversing antenna signals for diversity reception are integrated in the signal paths of the group antenna system so that the azimuthal main direction of reception is tracked with a defined tracking by setting a combination of the switching positions of the controllable switching elements.

Abstract: The invention relates to an active reception antenna comprised of a passive antenna component with a frequency-dependent effective length le. The output connections of this passive component are connected to the input connections of an amplifier circuit. The amplifier circuit consists of a field effect transistor and a low-loss filter circuit with an input admittance. The low-loss filter circuit is connected on its input to the source connection of the field effect transistor. On its output, the high-frequency reception signal is de-coupled, and the low-loss filter circuit is loaded with an effective resistance or conductance acting on its output.

Abstract: The invention relates to a diversity reception system for motor vehicles for digitally modulated terrestrial and/or satellite radio signals in the frequency range above 1 GHz. The system includes an antenna arrangement of which the reception signal is supplied to a radio receiver. The antenna arrangement is designed as an antenna system having several individual antennas and several antenna components, and contains a controllable logic switching device. The individual antennas and the several antenna components are positioned on the vehicle so that for discrete switching positions of the controllable logic switch, reception signals that are different in terms of diversity are available at the antenna connection point. A reception level testing device is provided for the comparative determination of the reception level contained in the data flow in the HF-channel with an HF channel bandwidth B.

Abstract: A diversity antenna for the meter and decimeter wave ranges installed on a conductively framed dielectric surface in the body of a motor vehicle and substantially assembled from rectangular part surfaces, for example in a roof cutout or trunk with a dielectric trunk lid. A substantially wire-shaped antenna conductor is installed parallel with the conductive frame and spaced from a part thereof of the dielectric surface less than one fourth of the width of the dielectric surface. The wire-shaped antenna conductor has an interruption site which define a pair of antenna connection terminals. A two-pole, electronically controllable impedance network is incorporated in series in at least one additional interruption site.

Abstract: An antenna for mobile satellite communication disposed on a substantially horizontally oriented conductive base surface having substantially linear conductor parts and an antenna connection point. The conductor parts have a substantially vertical extension portion, substantially horizontal extension portion which, together with the conductive base surface, form a high frequency conducting ring structure. The conductor parts are disposed in a plane, mounted perpendicular to the conductive base surface, and one of the vertical or horizontal extension portions is interrupted to form the antenna connection point. In a further interruption of one of the conductor parts, is provided at least one impedance connection point wired to an impedance.

Abstract: A scanning antenna diversity system for motor vehicles having at least two antennas disposed in a multi-antenna installation. The diversity system also contains a controllable logic circuitry, and a receiver for receiving a signal from the antennas. Connected to the receiver is a diversity processor controlled by the receiver, for stepping the logic circuitry to another switching position during the presence of reception interference. This occurs during the shortest possible comparison times, which are initiated in cyclic repetition upon expiration of a longer time interval by level comparison circuitry for detecting signals. In this case, the level comparison circuitry determines a maximum level switching position associated with the greater actual received signal in an actual receive situation. Thus, the level comparison time is selected sufficiently short so that the reception is not audibly impaired by the level comparison time.

Abstract: The invention relates to a receiver system for vehicles having an antenna and a receiver with an interference signal receiving device. This interference receiving device comprises a coupling element with an input for taking up the pulse-like interference radiation emitted by the vehicle aggregates and which interference radiation emitted by the vehicle aggregates and which interfere with the reception, with an evaluation circuit for presenting the interference radiation. A controllable transmission element is disposed within the receiver between transmission elements. Controllable transmission element is controllable with respect to its transmission behavior for the purpose of signal sampling, which also receives output signals of evaluation circuit so that during the duration of the interference pulses, the interference pulses interfered with receive and sample usable signals.

Abstract: An antenna for a diversity antenna system in a vehicle for mounting within the zone of a window pane surrounded by the electrically conductive body of the vehicle, consisting of a rear window pane having a substantially rectangularly or trapezoidally shaped surface and electrically conductors applied to the surface. A conductive surface in terms of high frequency, and coherent with respect to its edge conductors (12) is formed within the rear window pane. The edge conductors (12) are insulated at high frequencies from the vehicle ground so that each edge conductor (12) of a side of the conductive surface (1) has a minimum length of about &lgr;/10. At least one zone of the edge conductors (12) is provided in the form of a low-resistance coupling conductor (12a) with a continuous minimum length of about &lgr;/10.

Abstract: The invention relates to an antenna on the window of a motor vehicle having a thin electrically conductive layer which is transparent for light, but reduces heat transmission. The window is formed by a window pane which can be lowered into the bottom part of a vehicle door, and can be moved by a window lifter. The pane is covered with an area having a limited conductivity formed by a layer of limited conductivity. An antenna connection point is formed between a horizontal sealing strip placed at the lower border of the window aperture and the window lifter in a free area which exists when the window is closed. The connection point is connected by high-frequency, low-loss means to the area of limited conductivity.

Abstract: An antenna diversity system for receiving frequency-modulated (FM) radio signals with the phase-controlled summation of antenna signals for motor vehicles equipped with a multi-antenna system having at least two antenna output signals, and a receiver with an input for each of a first and a second received signal path, wherein the second of the two received signal paths contains a phase-shifter controlled by a phase-controller. The received signal has the same phase on the output of the phase-shifter as in the first signal path. The two received signals are added up in a phase-coincident manner in a summation circuit, and the added-up signal is supplied to the FM frequency modulator.

Abstract: The radio system for remote control operation in a stationary vehicle includes a transmitter outside of the vehicle which transmits a predetermined high frequency radio transmission in a meter wavelength band designed to be received only by a receiver located in the vehicle to the receiver (1) in a predetermined radio channel. The radio system includes at least two receiving antennas (2a,2b) mounted on the vehicle (5), which are decoupled from each other in a diversity-type manner in a frequency band of the radio channel and a respective one of these antennas is connected to the receiver tuned to this frequency channel with the help of a selection circuit (3) during a ready mode of the receiver (1).

Abstract: An antenna installation for radio and television reception in motor vehicles in the meter and decimeter frequency wave ranges with a first antenna and-at least one additional antenna on the vehicle. The receiving signal available at each connection point of the antennas are combined in a collecting network. The signal then flows out of the collecting network to a reception point to form an overall receiving signal. The line and collecting network is designed to select the highest possible reception quality for a motor vehicle moving through a reception field based upon a statistical average.

Abstract: An antenna disposed in a windowpane of a motor vehicle having an electrically conductive motor vehicle body having a direct current heating source. Disposed on the windowpane of the car is at least one heating field having at least one bus bar disposed on one side of the heating field. Connected to the bus bar at a connection point is a feeding network for feeding heating current into the bus bar. The feeding network is installed adjacent to the windowpane and comprises at least one magnetic core. Mounted on the at least one magnetic core is a primary winding which has a sufficient number of turns to transfer the high frequency, high impedance connection of the heating field. In addition, there is also a field compensation winding mounted on the at least one magnetic core, and is connected to a compensating current source so that this connection has no substantial effect in reducing inductive high resistence of this feed network and thus the high frequency reception of the antenna.

Abstract: A receiving antenna system for vehicles that eliminates interference in receiving signals. The interference detector is disposed within the receiver and generates and transmits an indicating signal, or a signal derived therefrom. Such signal can be formed in several different ways, and in the site of the antenna installation, it can be converted into a switching signal that only effects the switching condition in the antenna installation having a controllable switching circuit.

Abstract: An antenna for transmitting and/or receiving in the heating field of a window pane on a motor vehicle. The heating field has an HF-connection designed to couple or decouple high-frequency signals, and heating connections for feeding the heating power. An AC generator generates the heating wattage in the form of AC current, through a transformer. The heating power is supplied to the primary winding of the transformer and picked up on the secondary winding of the transformer and supplied to the heating field via heating connections. The primary winding and the secondary winding of the transformer are insulated to reduce the transmission of high frequency currents so that the heating field antenna does not have low resistance even at the lowest frequencies.

Abstract: A circuit for testing the function of mobile radio receiving installations is provided, wherein the circuit generates an HF-output signal that is used to test the system. A frequency mixer receives an oscillation signal (8) generated from within the superheterodyne receiver and an IF-carrier oscillation signal (32) generated from and oscillator (7) within the circuit. The frequency mixer generates an HF-output signal (12) that is dependent on the amplitude and frequency of the received oscillation signals. In alternative embodiments of the invention, the circuit of the invention is incorporated into the superheterodyne receiver, and the generated IF-carrier frequency 32 is eliminated and replaced with an IF-signal 22 produced by self-excitation of the superheterodyne receiver. With multi-antenna scanning diversity systems, additional switches and switching signals are included.

Abstract: An antenna for a windowpane or windshield, comprising a thin, electrically conductive layer flatly applied to an area of the windowpane. The layer is transparent to light and capable of reducing the transmission of heat through the windowpane, and creates a low-conductive area having non-negligible surface resistivity on the windowpane. Also provided is a substantially flat electrode made of highly conductive material, which is high-frequency connected with a reduced high frequency loss connected at at least one edge of said low-conductive layer, and also capacitively connected at high frequencies to an antenna connection point. The electrode is sufficiently long so as to minimize the loss created by the edge of the low-conductive layer. The low-conductive layer can also be sandwiched between glass panels such as in automotive safety glass and an additional electrode can be capacitively coupled to the main electrode.

Abstract: The invention relates to an antenna with electrically low overall height, preferably for frequencies in the GHz-range.

Abstract: A multi-antenna scanning diversity system uses an antenna diversity circuit adjacent to the antenna terminals, but remote from the receiver, whose input sees the antenna signals (A1) through (AN) and whose output provides a received signal selected by the diversity processor which then goes to the radio receiver via an bidirectional transmission line. The diversity circuit is also fed the radio receiver's IF signal scanned for interference by the diversity processor.In case of critical interference due to unfavourable reception conditions, the processor generates a switch signal causing another antenna to be selected.The system uses one common bidirectional transmission to conduct the RF signal from the diversity circuit to the radio receiver and the IF signal from the radio receiver back to the diversity circuit.

Abstract: The pane antenna for a very high or ultra-high frequency range includes heating conductors arranged on a window pane between two transverse busbars; at least one wire-shaped conductor forming a first antenna conductor crossing at right angles to at least one heating conductor and coupled by galvanic connection with the heating conductors at a low impedance to create a capacitive antenna region adjoining their crossing points; an antenna terminal outside the heating field on the window pane; a second antenna conductor connecting the antenna terminal with the first antenna conductor and a power supply network for supplying direct current to the busbars without an additional network for increasing impedance connected between the busbars and the vehicle body. The two transverse busbars are arranged so that each heating conductor extends between and is connected with the busbars.