Abstract: A waveform reconstruction circuit receives an rf signal from an antenna, digitizes it, and then generates an undistorted reconstructed waveform. The reconstructed waveform can then be conventionally mixed and demodulated to extract useful signal information with enhanced receiver fidelity and sensitivity.

Abstract: The process relates to communication between a mobile receiver fitted with at least two antennas of which one antenna is less sensitive, an internal transmitter and an external transmitter respectively inside and outside a vehicle.

Abstract: In a mobile radio apparatus, a matching circuit is selected to meet the detected condition detected by a switching control unit. Matching of the antenna to the RF circuit can be optimized and the antenna gain deterioration can be prevented.

Abstract: An integrated receiver with channel selection and image rejection substantially implemented on a single CMOS integrated circuit is described. A receiver front end provides programable attenuation and a programable gain low noise amplifier. Frequency conversion circuitry advantageously uses LC filters integrated onto the substrate in conjunction with image reject mixers to provide sufficient image frequency rejection. Filter tuning and inductor Q compensation over temperature are performed on chip. The filters utilize multi track spiral inductors. The filters are tuned using local oscillators to tune a substitute filter, and frequency scaling during filter component values to those of the filter being tuned. In conjunction with filtering, frequency planning provides additional image rejection. The advantageous choice of local oscillator signal generation methods on chip is by PLL out of band local oscillation and by direct synthesis for in band local oscillator.

Abstract: An RF cable-less interconnect arrangement couples a diplexer to a radio transceiver by providing each of the transceiver and the diplexer by means of respective pairs of RF transmission and receiver channel connectors. The two sets of connectors are supported at a prescribed spatial separation for blind-mating RF connectivity for either of two orientations and translation (insertion) of the diplexer into the radio. Eliminating lossy and relatively fragile RF cable, that would otherwise occupy space within the radio's housing, and require installation by a skilled technician during assembly of the radio, allows the customer to easily change the radio's frequency plan by simply removing, rotating and reinserting the diplexer.

Abstract: A waveform reconstruction circuit receives an rf signal from an antenna, digitizes it, and then generates an undistorted reconstructed waveform. The reconstructed waveform can then be conventionally mixed and demodulated to extract useful signal information with enhanced receiver fidelity and sensitivity.

Abstract: Disclosed is an electronic device having wireless communication functions via a pair of antennas. The device can function under two operating states, both with an omni-directional radiation pattern in the horizontal plane. This is accomplished by an antenna pair mounted separately thereon, the first antenna thereof being omni-directional in the horizontal plane when the device is operative under the first operating state, and the second antenna thereof being omni-directional in the horizontal plane when the device is operative under the second operating state.

Abstract: A device and method for splitting received signal energy among plural receivers in which received signal energy is provided to a first receiver which uses a primary portion of the received signal energy and reflects a reflected portion of the received signal energy, and in which the reflected portion is directed to an additional receiver(s) for use. Low loss directional circulators Or couplers may be used to direct the signal. The loss of signal energy to the first and subsequent receiver(s) is significantly reduced.

Abstract: A switch assembly, and an associated method, for a multi-mode mobile station operable to communicate pursuant to two or more communication services. Selected antenna transducers, or test ports, are selectably connected by way of the switch assembly to selected portions of the radio circuitry of the multi-mode mobile station. Non-mechanical switching is effectuated, thereby to provide appropriate connections of appropriate portions of the radio circuitry with the antenna transducers, or test ports, of the multi-mode mobile station.

Abstract: An antenna (100) includes a rectangular dielectric substrate (102); and a U-shaped conductive strip attached to a first surface of the substrate, the U-shaped conductive strip having two side members (202, 203), each about one-eighth a predetermined wavelength in length, and an end member (204) forming a substantially rectangular slot (206) extending parallel to the long edges of the substrate, the slot closed at a first end (212) by the end member, and open at a second end (208).

Abstract: A balanced antenna is provided for a mobile telephone which couples to the outputs from a balanced power amplifier stage without needing connection through a lossy conversion circuit. The balanced antenna comprises two radiating elements positioned opposite one another with the feed points positioned so that the radiating fields from the two elements superpose. A floating ground is also provided which reduces the effects of components located on the PCB under the antenna.

Abstract: A circuit for matching an amplifier to a radio-frequency line is described. In order to minimize the number of components required for matching the amplifier to different frequency bands, the circuit has a first capacitance for outputting the negative half-cycle of the transmission signal, which is rectified by a diode and is stored in a second capacitance. The stored negative voltage is, if required, fed back via two resistors and an inductance to a further diode.

Abstract: The invention relates to an arrangement for matching transmitting antennas in mobile stations, especially in mobile stations applying new transmission technologies, as well as to an arrangement for protecting a power amplifier feeding an antenna. In order to match an antenna (260), the strength of the field (re) reflected from the antenna is continually measured. The measurement data is used in controlling an antenna matching circuit (250) so that the strength of the reflected field is minimized. The measurement is carried out using a circulator (220) which also provides isolation, i.e. prevents the field reflected from the antenna from propagating back to the power amplifier (PA). In a multi-band apparatus, the band in use is also taken into account in the matching. The structure according to the invention saves space, as the number of relatively large components becomes smaller.

Abstract: An RF filter for a cellular radio receiver whose architecture includes a combination of signal circulators and bandpass filters which operate to selectively notch out sub-bands of the two cellular bands of the cellular radio transmission spectrum so that the sub-bands of both cellular bands can be separately directed to a radio capable of receiving either or both the A or B-band signals. In its preferred form, the architecture of the filter includes two circulators, three bandpass filters having mutually different bandpass characteristics, covering selected portions of the A and B band and a diplexor.

Abstract: An antenna diversity receiving system is disclosed which includes an antenna device with a plurality of FM antennas and a controllable switching circuit for sequentially switching through one of the plurality of FM antennas via an antenna cable to a receiver upon reception of a switching control signal. The receiver has a multipath detector coupled to a pulse generator for generating a pulse signal to be used as such switching control signal. To secure accurate detection of the switching control signal, the pulse generator is coupled to a pulse shaper to convert the pulse signal of the pulse generator into a pulse signal pair. The pulse signal pair has a first signal pulse followed by a second signal pulse having a signal polarity opposite to the signal polarity of the first signal pulse. The pulse signal pair has a waveform varying symmetrically around a reference level and is supplied through the antenna cable to the antenna device.

Abstract: The invention relates to an appliance for wireless reception of radio signals such as those which are transmitted, for example, in networks which are not based on wires (“wireless network”). A problem which frequently occurs in these networks is that the field strength distribution in a room is highly inhomogeneous due to reflections on walls, ceilings and objects. This can lead to the signal to be received being very severely attenuated at the location of the receiving antenna while, at a point only a few centimeters away, it can be received virtually without any attenuation. The invention thus provides a signal evaluation circuit which continually evaluates the reception field strength. As soon as the reception field strength falls below a specific threshold value, a drive unit reacts by changing the physical position of the antenna.

Abstract: An antenna diversity receiver comprises a zero-IF receiver connected to two antennas (102a, 102b) via switches (532,534). Simultaneous measurement of signal qualities from both antennas is possible by routing signals from the first antenna (102a) via a first mixer (106) and channel filter (116) and routing signals from the second antenna (102b) via a second mixer (108) and channel filter (118). A diversity controller (536) compares the signal qualities received from the antennas (102a,102b) during a data preamble to select a preferred antenna, then adjusts the switches (532,534) to route the signals from the preferred antenna to both input mixers (106,108). The amplifier (104a,104b) connected to the deselected antenna may be switched off during data reception, thereby minimizing extra power consumption.

Abstract: Disclosed are method and apparatus which measure signal level of an RF signal. The measured RF signal includes a baseband signal modulated onto a first carrier signal having a first frequency and the baseband signal includes program information and control information. The method and apparatus digitize the RF signal which includes the baseband control information and determine a signal level measurement from the baseband control information in the digitized RF signal. Furthermore, method and apparatus are disclosed which determine from the digitized RF signal whether a tagging signal is present in the RF signal.

Abstract: A receiver invention includes an antenna circuit unit having a high-frequency amplifier circuit connected to a reception antenna, a receiving circuit having a channel selection key, and a coaxial cable for connecting the antenna circuit unit and the receiving circuit. The receiving circuit includes a voltage adding circuit for adding, upon channel selection based on an operation of the channel selection key, a DC voltage corresponding to a frequency band to an AGC signal to supply it to the high-frequency amplifier circuit through the coaxial cable. A high-frequency gain of the high-frequency amplifier circuit is changed by using a voltage corresponding a frequency band of a received broadcasting frequency and an electric field intensity thereof.

Abstract: An integrated receiver with channel selection and image rejection substantially implemented on a single CMOS integrated circuit is described. A receiver front end provides programable attenuation and a programable gain low noise amplifier. Frequency conversion circuitry advantageously uses LC filters integrated onto the substrate in conjunction with image reject mixers to provide sufficient image frequency rejection. Filter tuning and inductor Q compensation over temperature are performed on chip. The filters utilize multi track spiral inductors. The filters are tuned using local oscillators to tune a substitute filter, and frequency scaling during filter component values to those of the filter being tuned. In conjunction with filtering, frequency planning provides additional image rejection. The advantageous choice of local oscillator signal generation methods on chip is by PLL out of band local oscillation and by direct synthesis for in band local oscillator.

Abstract: A waveform reconstruction circuit receives an rf signal from an antenna, digitizes it, and then generates an undistorted reconstructed waveform. The reconstructed waveform can then be conventionally mixed and demodulated to extract useful signal information with enhanced receiver fidelity and sensitivity.

Abstract: A broadcast coupler which couples both a broadcast radio receiver and communications equipment in a vehicle to the existing OEM vehicle antenna wherein no physical modifications are made to either the antenna mast or the antenna base or the antenna feed line. The broadcast coupler has a built-in tuner capability which permits the existing OEM supplied antenna to function as a low standing wave ratio (SAR) communications antenna. The broadcast coupler tunes the existing OEM antenna and provides the necessary isolation to permit the communications equipment, i.e., transmitter, receiver or transceiver, to function without detection by the operator of the vehicle. Since the existing OEM antenna is tuned by the broadcast coupler, the vehicle does not have to be modified and a new antenna does not have to be purchased.

Abstract: A monolithic active frequency selection circuit includes an input presenting a frequency-dependent impedance and a first gain block configured to provide less than unity voltage gain, a high input impedance and a low output impedance. An output of the first amplifier is coupled to the frequency selection circuit input. The frequency selection circuit includes a first phase shifter that, in one aspect, is formed by a first capacitor coupled between the first port and a reference voltage. The frequency selection circuit also includes a second amplifier configured to provide greater than unity voltage gain. The second amplifier has an input coupled to the output of the first amplifier and an output coupled to the input of the first amplifier. The frequency selection circuit further includes a second phase shifter, which may be formed from a capacitor coupled between the output of the second amplifier and a reference voltage.

Abstract: In order to select one or more microwave signals from among the signals which it receives, the reception device comprises switching circuits. The switching circuits are commanded by command signals. According to the invention, a switching circuit command signal consists of at least two sinusoidal signals generated according to the principle of voice-frequency dialling. The invention applies more particularly to the reception of signals from telecommunication and/or telebroadcast satellites.

Abstract: A waveform reconstruction circuit receives an rf signal from an antenna, digitizes it, and then generates an undistorted reconstructed waveform. The reconstructed waveform can then be conventionally mixed and demodulated to extract useful signal information with enhanced receiver fidelity and sensitivity.

Abstract: A semiconductor module having a built-in antenna element for use in a system of a band of millimeter-waves or quasi-millimeter-waves comprises a substrate, an antenna element, a semiconductor integrated circuit, and a hermetically sealing portion. The antenna element is mounted on one side of the substrate. The semiconductor integrated circuit is also formed on the same side of the substrate as of the antenna element. The semiconductor integrated circuit includes at least either of a transmitter signal processing circuit composed mainly of an amplifier circuit and a frequency converter circuit for processing a signal which is exploited in the system of the band of millimeter-waves or quasi-millimeter-waves and transmitted to the antenna element, and a receiver signal processing circuit composed mainly of an amplifier circuit and a frequency converter circuit for processing a signal which is received by the antenna element and exploited in the system of the band of millimeter-waves or quasi-millimeter-waves.

Abstract: The invention relates to a receiver system for the reception of a series of ultrashort, pulsed electromagnetic signals. Signals of this type usually require an extremely fast-acting receiver, necessarily situated in close proximity to the antenna. According to the invention, the presence of several passive components near the antenna will suffice.

Abstract: A high capacity broadband base station employs a wideband radio and phased array processing subsystem. This phased array antenna subsystem contains multiple sets or pairs of alternating receive only and transmit/receive elements distributed in a two dimensional spatial array. Each digital wideband radio performs both receive and transmit channel signal processing. In the receive direction, the digital representation of the entire spectrum for each antenna element is divided into channels for the particular waveform of interest. For a 5 MHz PCS GSM, the digital wideband radio separates twenty-four carriers into twenty-four (200 KHz wide) data streams, each of which is representative of a respective channel, and couples each channel to a digital signal processor. In the transmit direction, the radio combines the digital representations of the twenty-four individual channels supplied by the DSP into a single wideband channel for transmission.

Abstract: A receiving circuit includes: an antenna for receiving signal waves of two different frequency hands; a first receiving circuit for receiving a first receiving signal having a frequency; a second receiving circuit for receiving a second receiving signal having another frequency; a switch element for switching a signal path from the antenna to either one of the first receiving circuit and the second receiving circuit; a first diode; a second diode; and reverse bias voltage applying elements, each connected in parallel with one of the first diode and the second diode. The switch element is connected to a direct current power supply, and the switch element controls the connection of the direct current power supply such that the first diode and the second diode are biased in the forward direction when the first receiving signal is received and the first diode and the second diode are biased in the reverse direction when the second receiving signal is received.

Abstract: A retractable ½ wave antenna having an integral matching section that can be used on a cellular telephone will be matched to a transceiver circuit when extended. When the antenna is retracted, it acts as a ¼ wave antenna and will still be matched to the transceiver circuit.

Abstract: A system that partitions or divides the functions of a radio into channels and divides the functions of each channel into two major functions: 1) antenna interface and power amplification; and 2) hardwired mixing, modulation/demodulation and signal processing and further partitions the mixing through signal processing functions into the functions of a) programmable analog mixing and b) programmable digital modulation/demodulation and signal processing. Control and user interface functions, if needed for a particular application can also be functionally partitioned.

Abstract: When mixed modulation signal may be erroneously determined to be a signal intended to be received by a particular receiver the receiver checks whether prevailing received signal is a signal intended to be received by that receiver. When the received signal intended is other than a signal to be received, by that receiver the receiver turns off an antenna tuner to prevent impedance matching between the antenna side impedance and the radio section side impedance. When the received signal intended is a signal to be received, by that receiver the receiver turns on the antenna tuner to allow impedance matching between the two impedances.

Abstract: A low power switched diversity antenna system (200) includes two varactor tuned antennas (205, 207), each including an antenna element (505) and a varactor (515). The varactor tuned antennas intercept components of electromagnetic radiation that are substantially orthogonally polarized. One of the varactor tuned antennas is tuned to a desired frequency and the other is detuned, achieving a relative gain of the tuned varactor tuned antenna to the detuned varactor tuned antenna of at least 3 dB at the desired frequency.

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 method and apparatus enables a communication device (100) to operate in multiple bands, such as GSM 900 MHz, DCS 1800 MHz, and DCS 1900 MHz bands, by eliminating the need for a mixer for each band. In a dual band GSM/DCS 1800 radiotelephone, for example, the local oscillator (LO) injection frequencies for both GSM and DCS bands are provided to a mixer (234) through the use of combination filters (222, 246). Thus, the duplexing and matching requirements to the mixer input are simplified and the signal losses are minimized. The common output ports of the GSM RX/LO combination filter and DCS RX/LO combination filter are duplexed to the input of the mixer. Also, the input impedance matching of the mixer is designed to match the impedance for the received signals in each band, as well as provide an RF trap at the IF frequency. The match at the output of the mixer is designed to match the impedance of the IF filter and provides a low impedance to RF input frequencies.

Abstract: A waveform reconstruction circuit receives an rf signal from an antenna, digitizes it, and then generates an undistorted reconstructed waveform. The reconstructed waveform can then be conventionally mixed and demodulated to extract useful signal information with enhanced receiver fidelity and sensitivity.

Abstract: It is an object of the present invention to provide a variable attenuator which can be produced at a low cost and can suppress production of unnecessary resonance and propagation. When the radio frequency resistance values of PIN diodes 13 and 14 are higher than a characteristic resistance value of a signal line interconnecting radio frequency signal input terminal 1 and radio frequency signal output terminal 2, the sum of voltages applied to PIN diode 11 and PIN diode 13 and the sum of voltages applied to PIN diode 12 and PIN diode 14, that is, V3, are controlled so as to be fixed.

Abstract: A frequency selective noise reduction circuit and finds application in receiver demodulator arrangements in mobile telecommunication base stations. A receive signal is divided into two paths. One path includes a Phase Lock Loop circuit (PLL) which is employed to identify noise. The noise signal is inverted and then combined with the other signal.

Abstract: An apparatus for electrical line communications using FM video modulation, includes FM video modulation circuits and an impedance matching coupler at each of two or more locations along a pair of lines. The impedance matching couplers provide impedance matching, utilizing an air-core preselected frequency bands, sufficient to allow low-loss transmission of frequency modulated video signals. The coupler further eliminates noise and is matched resistively to the characteristic impedance of the line at the preselected frequency bands. A transmitter, receiver and associated circuits may also be provided at each location along the lines. The FM video modulation circuits, in combination with phase linear coupling techniques, provide for hi-fidelity video transmission over existing electrical lines, such as residential AC power wiring. In addition, a coupler with solid state impedance matching is provided.

Abstract: A micro-receiver for receiving a high frequency frequency modulated or phase modulated signal, including a single integrated circuit in BiCMOS technology and on which is integrated a high frequency amplifier, an oscillator, a modulator, an intermediate frequency filter, an intermediate frequency amplifier, a demodulator, a low pass filter and a low frequency amplifier. The integrated circuit includes in addition a muting or squelch circuit, a voltage multiplier as well as a standby circuit. The circuits working in a lower frequency range are implemented in CMOS technology, and operated in a very energy-saving way with a single-cell battery with a low battery voltage of 1.3 V. The voltage multiplier provides a higher operating voltage for the circuits working in a higher frequency range.

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: A mobile receiver for satellite broadcast comprises directive antennas, a navigation unit for generating a navigation signal representing a position and an attitude of an airplane, a control unit for generating a control signal for controlling the antennas, on the basis of the navigation signal from the navigation unit and prestored information indicating a position of a broadcasting satellite, and a drive unit for driving the antennas in response to the antenna control signal from the control unit to orient the directivity of the antennas toward the broadcasting satellite.

Abstract: A radio transceiver of the present invention includes a transmission line within a housing. The transmission line is comprised of a hollow center conductor and an outer conductor, both connected to a transceiver circuit. The transmission line is also connected to a low impedance connector which is coupled to the housing. A retractable 1/2 wave antenna having an integral matching section will be matched to a transceiver circuit when extended. When the antenna is retracted, the antenna is retracted within the center conductor and acts as a 1/4 wave antenna and will still be matched to the transceiver circuit.

Abstract: An RF apparatus (e.g., a wireless label) provides improved backscattering of an incident RF signal by utilizing a separate modulator diode, which connects across the antenna, to modulate the backscattering of the antenna. A separate detector diode connects across the antenna through an impedance matching network to detect modulated signals received by the antenna.

Abstract: Apparatus for electrical line communication that includes a coupler at each of two or more locations along a pair of lines, the coupler having capacitive circuits serially connected with an air-core transformer. The capacitive circuit is designed to resonate with the air-core transformer at a preselected frequency. A transmitter, receiver and modem may also be provided at each location. The apparatus incorporates a novel phase linear coupler which eliminates noise and is matched resistively to the characteristic impedance of the line at a preselected frequency. This apparatus therefore linearizes communication on the line and allows high speed data and voice communication over long distances.

Abstract: An adapter assembly for adapting a portable cellular telephone to receive an external replacement antenna or an external direct feed connection includes an adapter element and a retention element. The adapter element includes an antenna receiving bore at one end, and a positioning member at the other end, and further includes a latching member operable between first and second operative positions. The retention element includes a base cap with an extending actuator that biases the latching member into the second operative position where the adapter element is in engagement with body of the telephone.

Abstract: An antenna suitable for a radio telephone which is primarily comprised of a duplexer, a transmitter, and a receiver. The antenna is fabricated as a cover for sealing a box-like duplexer. At the same time, the cover is set up by a microstrip antenna which is comprised of a dielectric substrate and conductive pattern layers formed on the top and bottom surfaces of the dielectric substrate.

Abstract: A microwave antenna and receiver assembly is described for use at gigaherz frequencies wherein the antenna is a microstrip antenna and the receiver includes a stripline filter circuit which is integrated in a layered configuration with both the microstrip antenna and the amplifier so as to achieve a very low noise figure, a low SWR and preserve good receiver characteristics, while being easily assembled inside a common radome housing. An inexpensive substrate material formed of alternating layers of polypropylene and woven glass is described for use with the microstrip antenna and other microwave structures.

Abstract: A radio communication device (600) comprises a microstrip antenna (300) having a planar antenna element (302) and a ground plane (314) coupled to the planar antenna element (302). The microstrip antenna further comprises a dielectric material (304) positioned between the planar antenna element (302) and the ground plane (314), and a primary receiver element (325, 326, 328) mechanically coupled to the ground plane (314). The microstrip antenna (300) further comprises a feeder (308, 310) electrically coupled between the planar antenna element (302) and the primary receiver element (325, 326, 328) for feeding an intercepted radio signal therebetween for down conversion by the primary receiver element (325, 326, 328). The radio communication device (600) also comprises a secondary receiver element (828) coupled to the primary receiver element (325, 326, 328) for demodulating the intercepted radio signal after down conversion by the primary receiver element (325, 326, 328).

Abstract: A portable radio provided with a slidable antenna retractably supported by a housing, an antenna operating member movably mounted in the housing for projecting an antenna top portion from the housing by sliding the antenna in a first direction toward the outside of the housing or for releasing the antenna to enable the antenna to slide in a retracting direction opposite to the first direction, and an operating portion for operating the antenna operating member from outside the housing.