Abstract: An RF antenna and an associated receiver are proximately located in an integrated antenna/receiver unit thereby eliminating the need for baluns and inter-component cabling characteristic of prior designs. Integration of the receiver with the antenna provides for improved sensitivity as the need for utilizing signal dissipating and noise introducing cables and baluns to transmit the signal received by the antenna to the receiver is eliminated. Direct coupling of the antenna and receiver on a single gallium arsenide integrated circuit maintains balanced impedance from the antenna to the receiver.

Abstract: An adaptive multi-receiver shared antenna matching system and corresponding method includes an antenna (101). A plurality receiver devices (103) are operably coupled to the antenna (101). Degree of coupling between each of the receiver devices (103) and the antenna (101) is dynamically alterable dependent on a degree of coupling model (200) and different signals received by the antenna (101).

Abstract: A device for filtering wide-band signals at radio frequencies is usable either in a base station cellular telephony system or separately. The wide-band signal occupies a total frequency band comprising frequency bands allocated to that signal and a central frequency band extraneous to that wide-band signal. Within the device, the wide-band signal is mixed with a heterodyne wave to translate the signal from RF to IF. The signal at IF is then filtered by two surface acoustic wave (SAW) band-pass filters which have respective pass bands which correspond at IF to the allocated frequency bands of the wide-band signal, and which the SAW filters have the filtering effect of passing with low attenuation signals in those allocated bands while substantially attenuating signals and/or noise in the central extraneous frequency band between those allocated bands.

Abstract: When a radio frequency (RF) circuit is integrated into a movable housing element of an electronic device one must consider the affects of the surrounding area when the RF circuit is in a functioning position. A preferred embodiment is a radiotelephone (100) having an antenna (105) integrated into a movable housing element (101). The antenna (105) has two functioning positions, an opened and a closed position. The antenna (105) is tuned for efficiency when the movable housing element (101) is in the opened position. When the movable housing element (101) is in the closed position, a first pair of conductive plates (107, 109) located in the movable housing element (101) and a second conductive plate (113) located in the second housing element (103) are positioned to retune the antenna (105) due to the detuning affects caused by the close proximity of other electronic components located in the second housing element (103).

Abstract: An FM stereo receiving system and a method for aligning phases of RF signals received by multiple antennas. The FM stereo receiving system includes two antennas for receiving RF signals having a common frequency but potentially different phases. The system also includes an FM receiver having a detector output and a pilot output on which a pilot tone, such as a 19 kHz pilot tone, is present. A summer is included in the system for summing the RF signals and providing the summed signal to the receiver. The amplitude modulator of the system resides between one of the antennas and the summer to amplitude modulate the antenna's RF signal at a perturbation frequency which is a whole number multiple greater than 1 of the pilot tone. The receiver thus produces on its phase detector output a phase signal having a frequency equal to the perturbation frequency and a magnitude corresponding to the phase error between the RF signals which is connected in a feedback loop to align the phases.

Abstract: An arrangement for measuring the condition of a receiver antenna at a base station, utilizing an antenna amplifier positioned in connection with an antenna apart from other base station equipments, e.g., at a mast. A measuring signal is generated in connection with the other base station equipments at a frequency outside the frequency band used for radio traffic and applied through an antenna line to the antenna amplifier, in which the measuring signal is converted to the actual measuring frequency within the frequency band intended for the radio traffic.

Abstract: A vehicle radio receiver circuit includes two antennas for mounting on the vehicle. The antennas are significantly less than one quarter of a wavelength in length at the desired frequency of operation, and the outputs of the antenna elements are coupled to two inputs of an FM circuit and two inputs of an AM circuit, which includes summing circuitry. The FM circuit has an FM output for providing a received FM signal, and the AM circuit has an output for providing an AM signal that includes a sum of signals derived from the outputs of the antennas.

Abstract: In an earth-based receiving station for receiving radio signals transmitted from a satellite relay station, a common first frequency converter and at least two receivers are provided. One of the receivers is used as a control receiver to receive a CSC carrier frequency transmitted from the satellite, to generate a first local oscillator frequency phase-locked to the CSC carrier frequency, and to supply the first local oscillator frequency to the common first frequency converter. Other receivers are used as channel receivers for receiving channel frequencies. In case when the control receiver is in trouble, any other receiver can be used as a control receiver.

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 fast settling, wide dynamic range vector modulator for use in an interference cancellation system or the like includes a quadrature hybrid which receives an RF signal and divides the signal into a primary in-phase component signal and a primary quadrature phase component signal. A first 180.degree. hybrid receives the primary in-phase component signal and provides first and second secondary in-phase component signals which are 180.degree. out of phase with each other. A second 180.degree. hybrid receives the primary quadrature phase component signal and provides first and second secondary quadrature phase component signals which are 180.degree. out of phase with each other. A first switching device selects one of the first and second secondary in-phase component signals, and a second switching device selects one of the first and second secondary quadrature phase component signals.

Abstract: A portable radio apparatus having a casing thereof keeps a matching state of an antenna thereof in the call waiting state and in the operating state of the apparatus. The casing is foldable and expandable and accommodates therein a transmitting and receiving circuit connected via a variable matching circuit to the antenna. The matching circuit is connected to a sensor disposed in the casing for sensing a folded state thereof. Depending on a result of the sensing operation of the sensor, the matching circuit changes the matching state.

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 wristwatch paging receiver is provided with an antenna matching network that automatically retunes the network at the beginning of a listening interval. During the retuning operation, a control signal is applied to a variable tuning element in the matching network, such as a varactor diode, and is swept from a minimum value to a maximum value. This sweeping is desirably performed in discrete voltage steps that correspond to unit increments of varactor capacitance. A feedback signal from the receiver, such as an AGC signal, is monitored during this operation to note which varactor bias signal yields the maximum AGC signal. After the sweep is concluded, the apparatus applies to the varactor the bias voltage that yielded the maximum AGC signal during the sweeping operation. This bias voltage is maintained through the end of the listening interval. At the beginning of the next listening interval, the process may be repeated.

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: For setting up LOS radio links between mobile calling transmitting/receiving stations and other mobile or stationary remote transmitting/receiving stations in a predetermined operating area, especially in the frequency range above 1 GHz, every mobile station is provided with an electronic memory with an associated processor. The memory stores the respective geographical and topographical data of the operating area. Prior to the setting-up of a radio link, the transmission loss between the stations is calculated in accordance with known model calculations on the basis of the geographical and topographical data stored in the memory by inputting into the processor the current location data of the calling station and the remote station.

Abstract: A radio frequency field strength enhancement system (402) having a member (404) with at least one tuning impedance (405) for adjusting a desired frequency response associated with the member (404) and means for retaining (408) the member (404) in close proximity to a radio frequency communication device (401) having an integrally mounted antenna system (214). When the radio frequency communication device (401) is brought within close proximity of the RF field strength enhancer (402), the power received or transmitted by the integrally mounted antenna system (214) in the RF communication device (401) is enhanced.

Abstract: An antenna tuning system and method are disclosed for use with a tunable receiver coupled to an external antenna, where the receiver has a local oscillator whose frequency is a function of the frequency to which the receiver is tuned. The tuning system includes circuitry for receiving the radio frequency emissions from the local oscillator, and for determining the frequency of those emissions. From the local oscillator frequency, the frequency to which the receiver is tuned is determined, and the antenna is tuned to match that frequency.

Abstract: An amplifier loaded with a constant bandwidth tuned circuit is provided with an output series coil, and with a resistance in series with the output coil and a subsequent load to provide attenuation at high frequencies for maintaining the total overall gain of the amplifier and tuned circuit load constant with increasing frequency while simultaneously maintaining the bandwidth of the tuned circuit constant with increasing frequency.

Abstract: A directional H.F. broadband transformer made by a printed circuit technique includes an insulating support carrying a two-hole ferrite core. A planar coil arrangement includes two web spirals wound around outer legs of the core and each being coupled to an elongated web arranged in the same plane and passing through a corresponding hole of the core. The two elongated webs are formed with an input terminal, an output terminal and a tap terminal of equal impedance. An isolated conductive layer mounted above the webs on the insulating support is capacitively coupled with the coil arrangement and with a ground layer to reduce values of series connected distributed capacitors resulting between respective webs and the ground layer.

Abstract: A technique for reducing the average fade duration of signals in a radio system by simulating motion of a plurality of transmitting antennas is disclosed. This simulation is accomplished by slowly and continuously varying a characteristic of the modulated carrier signal supplied to the antennas. The altered characteristic can either be the power of the modulated carrier signal supplied to each of the antennas or the phase between modulated carrier signals coupled to the antennas. This technique can also be applied at a receiver to reduce the average fade duration of signals arriving thereat by simulating motion of a plurality of receiving antennas.

Abstract: An antenna for a vehicle-mounted receiver/transmitter includes: a driver for extending and retracting an antenna connected to the receiver/transmitter; a selector for selecting a frequency to be received and/or transmitted by the receiver/transmitter; and a controller which operates in response to an output from the frequency selector for causing the driver to extend and retract the antenna by the length corresponding to the frequency, and for retracting almost the entire antenna into the body of the vehicle when the receiver/transmitter is not operating.

Abstract: Apparatus is provided for coupling one of two signal sources to the antenna terminals of a television receiver. An antenna switch is provided which includes solid state switching elements which when receiving a biasing voltage connects one of two input ports to an output port for delivering a signal to a television receiver. In the unbiased state, the remaining input port is connected to the television receiver antenna terminals. High isolation is provided to prevent stray radiation from one signal source being received by a second signal source.

Abstract: Reflected signal distortion in vehicular FM receivers is eliminated or largely suppressed by providing a plurality of antenna elements of the vehicle antenna (13, 100) with different directional characteristics, which are selectively connected to the vehicle receiver (10, 30; 104, 106) if a reflection is sensed in the reflection recognition stage (30, 106). In one embodiment (FIG. 1), the antenna (13) is subdivided into an upper and a lower portion (14, 15), about one-third down its length, the lower portion being surrounded by shielding elements (17-20) positioned about 90.degree. offset from each other, and selectively connectable to, or disconnectable from, ground or vehicle chassis in dependence on sensed distortion or reflection recognition pulses, to reduce the effective antenna length and change the directivity.

Abstract: In a television receiver having an in-cabinet receiving antenna that has a plurality of electrically controllable states having different radiation reception pattern conditions, an automatic antenna steering apparatus selects one of the controllable patterns. In response to the selection of a channel to be received, the apparatus sequences through each of the plurality of states and determines the relative amplitude of the received signal in each. When the amplitude of received signals in all of the states has been determined, the apparatus selects the state wherein the received signal is of a predetermined amplitude condition. One convenient measure of signal amplitude is an internal AGC signal of the receiver. In one embodiment of the present invention a microcomputer is employed to control the various operations to establish the antenna in the state producing the predetermined amplitude condition.

Abstract: Tuning circuitry for a VHF television (TV) antenna tunes such antenna for signals corresponding to the TV channel selected and couples those signals to the tuning system of a television receiver. An antenna has a pair of signal terminals across which the tuning circuitry connects to form a resonance circuit therewith for tuning the antenna. A variable capacitance responds to a control voltage to develop the appropriate value of tuning capacitance. Impedances, e.g. inductors or capacitors or resistors, are coupled to the resonance circuit at least at selected times by switches. An amplifier couples signals from the resonance circuit to the tuning system of the TV receiver.

Abstract: Apparatus for use with a television receiver for selectively inhibiting reception of television broadcast signals. The apparatus includes a number of signal generating circuits, each respectively set to generate an electrical signal substantially equal to the carrier frequency of a corresponding television broadcast signal, and timer capable of being preset to activate and deactivate selected oscillators on a timed basis. The signal generating circuits are coupled to the antenna input leads of the television receiver so that when activated the electrical signals produced thereby cause sufficient interference with the corresponding incoming television broadcast signal to effectively block reception.

Abstract: A wide band impedance matching device is described for matching the impedance of an antenna transmission line to a radio transceiver over a wide band of radio frequencies. The device includes an impedance matching network having an inductor and two capacitors that electrically interconnect in either a capacitance "T" mode or a capacitance ".pi." mode. The device also includes an efficient bypass circuit that is capable of electrically bypassing the impedance matching network to effectively directly interconnect the antenna transmission line to the transceiver.

Abstract: An automatic gain control circuit for an AM receiver uses a signal having the same wavelength but reversed in phase with the signal in the antenna circuit. A variable resistance attenuator element such as a biased FET or PIN diode is used in the external antenna circuit having a winding to selectively attenuate the input signal to the tuning circuit including a secondary winding. Gain control is performed in an analog manner with respect to the input signal of the external circuit.

Abstract: A radio receiver comprises an antenna circuit represented by an equivalent circuit consisting of an antenna electromotive force, an antenna capacitance in series with said electromotive force and a cable capacitance in parallel with them, a negative capacitance circuit connected to the antenna circuit for at least partially cancelling the antenna capacitance and the cable capacitance and a tuning circuit for receiving the output of the antenna circuit. The negative capacitance circuit, composed of a capacitor, transistors and the like, improves the S/N ratio.

Abstract: A very high frequency tuner for selection of a broadcasting signal through variation of a capacitance value formed across a voltage controlled variable capacitance diode responsive to a tuning control voltage comprises an improved interstage tuned coupling circuit between a high frequency amplifier and a frequency converter of the very high frequency tuner for transmission of the output signal.

Abstract: A matching coupler in an antenna system to power transfer in matching characteristic impedance of an antenna and a transmission line using a ganged variable capacitance with a resonate coil and another variable capacitance in series with a transmission line and an antenna.