Abstract: In a first embodiment, the invention relates to an arrangement for operating a plurality of terminal devices (6) on a common antenna (4) with a coupling network (2) comprising a first separator (8) associated with the antenna (4) and a second separator (10) associated with the respective terminal (6). In a second embodiment, the invention relates to an arrangement for operating a plurality of terminal devices (6) on a common transmitting antenna (4″) and on a common receiving antenna (4) which is separate from the common transmitting antenna (4″) with a coupling network (2) comprising a separator (10) which is associated with the respective terminal.

Abstract: A novel terminating differential bus receiver with automatic compensation for process, voltage, and temperature variation is presented. A termination circuit is connected internal to the integrated circuit to the input of a differential receiver in parallel with a transmission line connectable to the receiver. Both the termination circuit and the differential receiver are implemented with at least one p-channel transistor and at least one n-channel transistor, such that the p-channel transistors of the termination circuit and receiver and the n-channel transistors of the termination circuit and receiver are ratioed to vary similarly under PVT variation.

Abstract: A transmission line adapter for high speed interface. A receiver receives input signals via a transmission line. An active termination circuit is selectively connected to the transmission line in parallel with the receiver according to a receive condition. A self-terminated driver circuit outputs a first voltage and a second voltage according to output data. A selective circuit for selectively connects the self-terminated driver circuit to the transmission line when output of the self-terminated driver circuit is a first voltage, and selectively connects the self- terminated driver circuit or the active termination circuit to the transmission line when the output is a second voltage.

Abstract: In a radio transceiver operating in a time division duplex system, a cancellation use transmission signal which is reverse in phase and equal in amplitude to a leakage transmission signal from an antenna in the signal transmission is supplied to an input port of the receiving amplifier of a receiver connected to an antenna system applied in common to the signal transmission. The transmission signal is fed via a circulator, which separates a transmission and reception path, to the antenna. The leakage transmission signal from the antenna is inputted via the circulator to the receiving amplifier. The cancellation use transmission signal is fed to the receiving amplifier via a second circulator which distributes the transmission signal and cancellation use signal disposed at an output side of the transmitting amplifier.

Abstract: A cellular phone includes two antennas, namely, a first antenna made as a rod antenna and a second antenna made as a helical antenna. A circuit board is housed in the casing of the cellular phone. The circuit board has an extended board portion which is projected upward from the upper edge and which corresponds in position to the antennas. An impedance matching circuit, which is made as a folded wiring pattern, and a feeding pad are formed on the extended board portion of the circuit board.

Abstract: A simply structured converter for satellite communication reception which can contribute to reducing signal losses and to simplifying the assembling work is to be provided. Orthogonal bipolarized signals transmitted from a satellite are branched into two propagation paths within a waveguide, and a horizontally polarized wave is caused to proceed in a first propagation path, while a vertically polarized wave is caused to proceed in a second propagation path. A pair of probes are supported by a circuit substrate fitted to a case, and tips of the probes extend into two waveguides provided in the case. By integrating the waveguide and the case by fixing means such as bolts, the first propagation path and the first waveguide are let to communicate with each other, and so are the second propagation path and the second waveguide.

Abstract: The present invention provides a method and apparatus for carrying signals having different frequencies in a space-deployed antenna system. When the antenna system is in a first mode, DC power, command information and RF signals (1) are multiplexed via a multiplexer, (2) propagate along a RF transmission line and (3) are appropriately demultiplexed by a demultiplexer associated with each T/R module. Similarly, when the antenna system is in a second mode, telemetry data and RF signals (1) are multiplexed via a multiplexer, (2) propagate along the RF transmission line and (3) are appropriately demultiplexed by a demultiplexer at a driver stage. By using the RF transmission lines associated with each T/R module to deliver (1) DC power, (2) command data and (3) RF signals in the first mode and to deliver (1) telemetry data and (2) RF signals in the second mode, the DC power and command/telemetry wire harnesses (and their respective conductors) may be eliminated.

Abstract: A signal selecting circuit comprises a first switch means connected between a first input terminal and a common output terminal, a second switch means connected between a second input terminal and the common output terminal, a first microstrip line for connecting the first switch means and the common output terminal, and a second microstrip line for connecting the second switch means and the common output terminal, wherein a length of the first microstrip line is set to be approximately odd-numbered times of 1/4 wavelength of a frequency of an image signal relative to the second mode reception signal, and a length of the second microstrip line is set to be approximately odd-numbered times of 1/4 wavelength of a frequency of an image signal relative to the first mode reception signal.

Abstract: An apparatus and method produce a plurality of output signals (917-921) with fixed phase relationships therebetween. The apparatus (900) includes a first signal generator (901), a second signal generator (903), and a signal processor (907). The first signal generator produces a first input signal (911) at a first frequency. The second signal generator produces a second input signal (915) at a second frequency, wherein the second frequency is an integer multiple of the first frequency. The signal processor receives the first and second input signals and produces a plurality of output signals (917-921) having fixed phase relationships therebetween at the first frequency, wherein the fixed phase relationships are based on the integer multiple and wherein each of the output signals has a single, determinate phase relative to the phase of the first input signal.

Abstract: A mobile communications system for transmitting or receiving a broadcast signal and designed for mounting on in a vehicle has a transmitter or receiver and one or more antennas electrically connected to the transmitter/receiver. The system is mounted on or in a vehicle so that the transmitter/receiver and the antenna(s) are concealed. The system includes a GPS unit for receiving and processing a GPS and signal a cellular telephone unit for transmitting a fix of the vehicle location (to the police, for example). The system is particularly useful in recovering stolen vehicles and deterring theft.

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: In a mobile radio communication system where a base station is connected to a public switched telephone network, a hybrid unit and an echo canceler are provided in the base station. A mobile radiotelephone unit receives a base-to-mobile coded speech signal from the base station on a downlink channel and transmits a mobile-to-base coded speech signal on an uplink channel. In order to avoid the interruption of a base-to-mobile speech signal at the echo canceler which would occur as a result of a delayed, high-amplitude mobile-to-base analog speech signal, the mobile unit compares the energy parameter of the mobile-to-base coded speech signal and the energy parameter of the base-to-mobile coded speech signal, determines the difference therebetween when the former is higher than the latter, and reduces the energy parameter of the mobile-to-base speech signal by an amount corresponding to the difference.

Abstract: A transceiver system for interfacing digital modems with radio frequency signals including an antenna, an antenna interface system and a modem interface system separated by a cable. The antenna is placed in a location having optimal reception and in close proximity to the antenna interface system. The cable couples the antenna interface system to the modem interface system. The modem interface system includes a two state variable attenuator and an attenuation register that are configured to either reduce the strength of the receive (Rx) signal when the modems are located near a base station, or to transmit the Rx signal without attenuation when the concentrated subscriber unit is at a more distant location. The outgoing, or transmit (Tx), signal is also attenuated in a similar manner to the incoming signal. A signal loss detection system includes a detector located in the modem interface system that receives an oscillating signal transmitted from the antenna interface system through the coaxial cable.

Abstract: A filter circuit having an amplifier stage, an upstream filter and a downstream bandpass filter. The filter includes, inter alia, a rejection circuit tuned to an intermediate frequency and a series circuit, tuned to an image frequency and formed by a capacitor and a .lambda./4 coaxial stub. The inductance formed by the coaxial stub is shared by the series circuit and the rejection circuit.

Abstract: A modular antenna driver is provided for extending the area of coverage between a base station connected to a CATV cable system and a plurality of cordless handsets. The driver includes a duplex circuit connected to the CATV cable and tuned for upstream and downstream communications with the base station over the cable. A core circuit connected to the duplex circuit includes circuitry interconnected to perform and of sufficient bandwidth to perform communication functions common to at least two different handset types. At least one removable module is selectively insertable into the driver and includes circuitry interconnected to perform communication functions characteristic of one handset type wherein one such module will may be replaced by a second module for a different second handset type. In the alternative, multiple removable modules may be simultaneously employed in the driver to permit simultaneous compatibility with a plurality of handset types.

Abstract: The present invention is directed to a dynamic range enhancing system for increasing the dynamic range of a transmission link, characterized as either an analog or digital link. The system includes a pre-processing unit, provided at a first location, that receives, as input, a transmit signal, and a post-processing unit, provided at a second location, remote from the first location, that receives, as input, a signal transmitted over the transmission link. The pre-processing unit includes a first signal level adjusting device for adjusting a signal level of the transmit signal to be transmitted over the transmission link and a control signal maybe provided for controlling the post-processing unit, and the post-processing unit includes a second signal level adjusting device for adjusting a signal level of the adjusted transmit signal transmitted over said transmission link.

Abstract: In a portable satellite communication equipment including a transponder for transmission and reception, and an antenna portion which is electrically coupled to the transponder, the antenna portion has first and second common flat antennae. The first and the second common flat antennae are common to both the transmission and the reception and are foldably coupled to each other.

Abstract: The present invention is directed to a dynamic range enhancing system for increasing the dynamic range of a transmission link, and also to a process for increasing the dynamic range of a transmission link. An instruction setting process is also provided for defining a set of instructions, for a control device of the system, which detects, at an initial position along the transmission link, the level of a transmit signal adapted to be transmitted over the transmission link. The control device controls a first signal level changing device and a second signal level changing device in response to the detected level. The first and second signal level changing devices, respectively, process the transmit signal level before and after transmission over the link.

Abstract: A concealed antenna system for motor vehicle radios replaces a radio chassis preamplifier with a remote radio frequency amplifier packaged with a filter module adjacent the antenna conductors to reduce the noise floor before transmitting the signal by a highly capacitive cable to the radio chassis. The dynamic range of the antenna system is improved by an automatic gain control feedback signal from the radio chassis to the RF amplifier so that the gain of the amplifier is reduced in the presence of a strong AM signal. Preferably the antenna conductors comprise embedded conductors in an insulating panel of a motor vehicle such as the vehicle rear window, and the AM conductor may be conveniently provided by the heater grid for the window panel.

Abstract: A satellite broadcasting reception system has a satellite antenna for receiving electromagnetic waves and a signal cable for transmitting signals produced upon reception of the electromagnetic waves by the satellite antenna. A receiver receives the signals transmitted over the signal cable, and a reception level indicator is connected to the signal cable for indicating a reception level of the electromagnetic waves on the basis of a control signal transmitted from the receiver over the signal cable.

Abstract: A distributed antenna system is provided which is formed from a series of modular stages interconnected by cables. Each stage may include an antenna, a filter, a compensating amplifier and preferably elements for impedance matching to connecting cables. Connecting stages also include a coupler for combining the output from the stage antenna with the output from the preceding stage and passing the combined signal to the stage output. Where the stages are part of a transmitting system, the coupler is replaced by or functions as a splitter, an input thereto from, for example, a preceding stage, being applied to the stage antenna and to the stage output.

Abstract: A television receiver powered by an alternating current power source includes an electrically conductive chassis coupled to one side of the AC source, a radio frequency tuner coupled to the chassis, and a coaxial cable having an inner conductor and an outer shielding conductor for supplying filtered radio frequency signals to the tuner. The outer conductor is comprised of an electrically conductive housing circumposing the inner conductor for at least a portion of its longitudinal length, and providing electrical connection and mechanical support for the cable assembly. Filtering of the signal is provided by one or more ferrite beads disposed about the outer conductor, and capristor/capacitor devices.

Abstract: The present invention is directed to a dynamic range enhancing system for increasing the dynamic range of a transmission link, and also to a process for increasing the dynamic range of a transmission link. An instruction setting process is also provided for defining a set of instructions, for a control device of the system, which detects, at an initial position along the transmission link, the level of a transmit signal adapted to be transmitted over the transmission link. The control device controls a first signal level changing device and a second signal level changing device in response to the detected level. The first and second signal level changing devices, respectively, process the transmit signal level before and after transmission over the link.

Abstract: The invention relates to a circuitry by means of which it is possible to switch to a mobile telephone that antenna out of two or more antennae which has the best signal, without substantial alterations in the mobile telephone itself. According to the invention, the antennae (A, B), the antenna selection switch (2) and the peripheral circuits (5, 6) connected to it constitute an integrated part which is separate from the actual mobile telephone (1) but can be coupled to it by means of an antenna cable (3), and the antenna cable (3) is coupled to the radio part of the mobile telephone (1) by mediation of a signal combining circuit (4) which transfers to the antenna cable (3) the supply voltage (V) and the antenna selection switch (2) control pulse, and transfers and selects the RF signal.

Abstract: A system intended for the simultaneous reception of several TV channels retransmitted by satellites. This system comprises a multi-frequency microwave frequency head, installed in an external unit, whose inputs are connected to the satellite antennas. Wide band demodulation is made possible by a microwave frequency source controlled by a synthesizer. Digital signals transmitted by a link cable ensure programming of the synthesizer and therefore of the selected TV channels. A remodulation in amplitude modulation is performed for supplying signals in the 40-860 MHz band, carried by an existing link cable for terrestrial antennas. The system finds particular application to the simultaneous reception of several TV channels.

Abstract: A dual function antenna system and method. A system is provided for using a single antenna for both the reception of low frequency navigational signals, such as LORAN-C, and high frequency communications signals in the VHF region. The antenna is at a remote location from a low frequency receiver and a high frequency transceiver. Both the low frequency and the high frequency signals are coupled to the receiver and transceiver, respectively, over the same transmission line at one end thereof. A preamplifier is provided at the location of the antenna to increase the strength of the low frequency signal applied to the transmission line. A high pass filter is provided to couple the antenna and the transmission line and prevent feedback from the output of the preamplifier from reaching its input. The other end of the transmission line is coupled to the high frequency transceiver by a high pass filter, and to the low frequency receiver by a low pass filter.

Abstract: An automatic control for compensating for the voltage drop between an antenna receiver and a remotely interconnected down converter wherein an operational amplifier senses the voltage drop due to the interconnecting cables, amplifies that voltage, and adds it to the actual tuning voltage to fully compensate for the voltage drop.

Abstract: An integrated receiver antenna device comprising a pair of antenna elements providing a spiral antenna for receiving radio frequency signals over a broadband of frequencies with an extended high frequency limit and providing high sensitivity over the broadband of frequencies. The elements each have first and second ends and provide a pair of interwound conductive windings with their first ends positioned proximate to each other at the center of the antenna for providing sensitivity at the high frequency limit of received radio frequency signal, while the second ends of the elements are displaced from the first ends and positioned at the periphery of the antenna. A detector mixer unit is connected between and positioned proximate to the first ends of the antenna elements for deriving radio frequency signals received by the antenna elements and receiving an input signal for providing an oscillating signal at the detector mixer unit for producing an output signal.

Abstract: The invention is a high frequency hetrodyne receiver front end for receiving a communications signal comprising a desired information frequency and an undesired image frequency. The receiver comprises a bandpass filter, a preamplifier responsive to the bandpass filter, a mixer and a coupler means between the preamplifier and the bandpass filter. The coupler means defines a reactive short at the undesired image frequency due to impedance characteristics of the coupler means. The coupler means thereby eliminates the image frequency noise at the input of the preamplifier. Preferrably the coupler means is a transmission line of a length L where L equals .eta..pi./.beta. and .eta. is an integer and .beta. is proportional to the wavelength of the image frequency.

Abstract: A compact antenna system for use in connection with pay television reception comprises a resonant cavity including a small dipole, the latter being connected to a circuit board containing circuitry for converting the received pay television signal to a frequency usable by the television receiver of the subscriber. The member defining the cavity is affixed to the circuit board, which in turn is mounted upon a holder attached to the exterior of the structure in which the television receiver is located. The circuit board includes a preamplifier-filter stage to filter extraneous signals and to promote preamplification of the signal from the antenna. The preamplified signal goes to the input of a mixer and from there is filtered to the frequency of the channel selected by the user of the television receiver. At least one triangular circuit element is utilized in the preamplifier and in the mixer.

Abstract: An antenna system is disclosed for plural band radio receivers having a common antenna. The system is especially adapted for AM/FM automobile broadcast receivers and may be used with a CB transceiver with a tri-band antenna. An impedance transforming means is provided at the base of the antenna and a single transmission line or lead-in cable extends from the impedance transforming means to the AM/FM receiver. The impedance transforming means has a high input impedance for the AM and FM bands and a relatively low output impedance to minimize the signal loss in transmission from the antenna to the receiver. The impedance transforming means includes a field effect transistor in a common source configuration and means are provided to produce substantially 100% voltage degeneration for both AM and FM signals.

Abstract: An electromagnetic noise source locator is comprised of an audio amplifier which is connected to drive a speaker and to which is connected at the input a series circuit that includes a very small antenna loop of area less than 1 in.sup.2, a diode and a capacitor. This apparatus responds only to bursts of radiated energy and furthermore responds only to such bursts having frequency components over about 1 GHz. It is therefore particularly suitable for the selective sensing and location of sparking gaps as may occur on power lines.