Patents Examined by Christine K. Belzer
  • Patent number: 5265274
    Abstract: A combined keypad and speaker portion (10) is provided wherein a membrane keypad (26) having a plurality of keys (28) has a plurality of speaker sound perforations (38) interposed between the plurality of keys (28).
    Type: Grant
    Filed: September 1, 1992
    Date of Patent: November 23, 1993
    Assignee: Motorola, Inc.
    Inventors: William J. Knutson, Bernard V. Gasparaitis
  • Patent number: 5263193
    Abstract: High receiver sensitivity and narrowband coherent resolution can be achieved at millimeter and submillimeter wavelengths through the process of heterodyning or intermediate frequency (IF) generation. The two frequencies, whose IF is being generated, need not be very stable in frequency or phase themselves. The requirement is only, that they fluctuate identically in frequency and phase, so that their fluctuations cancel at the IF. This can be achieved by deriving both from one and the same source. We have applied this process twice in a millimeter and submillimeter receiver of high sensitivity and resolution. At the same time the receiver is very simple, since the frequency and phase stability of the two sources involved does not affect sensitivity and resolution.
    Type: Grant
    Filed: May 31, 1991
    Date of Patent: November 16, 1993
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Uve H. W. Lammers, Richard A. Marr
  • Patent number: 5263176
    Abstract: In a multi-station radio communications system wherein plural channels are accessible for communication between plural fixed stations and plural mobile units (viz., dynamic channel assignment) and wherein each of plural fixed stations selects a channel according to channel assignment priority data, the radio channels are grouped into a plurality of channel groups. The channels in each of the channel groups forms a numerically looped sequence of channels. The first channel of the numerically loop sequence in one channel group is different from the first channel of the numerically looped sequence in each of the other channel groups. Each of the plural fixed stations is set to select the channel having the highest priority or to select one of the first channel of the numerically looped sequence and a channel nearest to the first channel in the event that a plurality of channels have the same priority.
    Type: Grant
    Filed: February 8, 1991
    Date of Patent: November 16, 1993
    Assignees: NEC Corporation, Nippon Telegraph and Telephone Corp.
    Inventors: Susumu Kojima, Tetsuro Hanazawa
  • Patent number: 5263195
    Abstract: The present invention relates to a radio receiver for receiving a radio signal, a first circuit for beating the signal to zero intermediate frequency in phase and quadrature shifted signals, a circuit for amplifying the in phase and quadrature shifted zero intermediate frequency signals, a second circuit for beating the amplified intermediate frequency signals to predetermined non-zero intermediate frequency in phase and quadrature shifted signals, a summer for summing the non-zero signals, and a circuit for applying the summed signals to a discriminator to obtain an output signal. Other embodiments are extended POCSAG for enhanced battery saving, paging sequence numbers for reception integrity control, digital AFC, script control of the pager for organizer/schedule applications, a vibrator holster for improved pager format and saving of battery power, intelligent low battery detection, and features arising from electronic on/off function.
    Type: Grant
    Filed: March 28, 1991
    Date of Patent: November 16, 1993
    Assignee: Silcom Research Limited
    Inventors: Gyles Panther, J. Peter Williams
  • Patent number: 5257409
    Abstract: This disclosure discusses a programmable frequency synthesizer arrangement having programming feedback capability used to avoid undesirable operation due to random hard and soft faults. The arrangement operates by supplying appropriate programming information, receiving the same, subject to random hard or soft faults, and, in response, directing the operation of a frequency synthesizer (10). The feedback capability is accomplished by generating a feedback signal (35, 36) indicative of the programming information as applied to the frequency synthesizer, generating a reference signal representative of the appropriate programming information, comparing the two signals, and blocking undesirable operation of the frequency synthesizer if the comparison indicates the occurrence of a random hard or soft fault. Further disclosed is a wireless communications transceiver with the programmable frequency synthesizer arrangement.
    Type: Grant
    Filed: October 18, 1991
    Date of Patent: October 26, 1993
    Assignee: Motorola, Inc.
    Inventors: Robert J. Sarocka, David D. Neperud, Peter P. Walter, Tim J. Manczko, David H. Spensley, Jr.
  • Patent number: 5257410
    Abstract: Briefly, according to the invention, a multi-unit communication device having a transceiver unit 108 and a control unit 104 is provided. The transceiver unit 108 transmits and receives information signals having digital and analog portions. The control unit 104 provides for operator interface to the communication device. The communication between the transceiver unit 108 and the control unit 104 is conducted on a single pair of wires 112 using ISDN format.
    Type: Grant
    Filed: March 22, 1991
    Date of Patent: October 26, 1993
    Assignee: Motorola, Inc.
    Inventors: William R. Meszko, Graham G. Haddock, III
  • Patent number: 5257398
    Abstract: In a cellular radiotelephone network, there is provided a mechanism for dynamic frequency reuse. It comprises: allocating according to one reuse pattern during one time interval at least one of a plurality of hopped carriers and allocating according to another reuse pattern during another, substantially non-overlapping time interval that hopped carrier, all in substantially non-interfering time synchronism with any proximal reuse of that carrier. The attendant advantage is the realization of a dynamically allocatable frequency reuse, using shared carriers and frequency hopping to provide the desired C/I performance.
    Type: Grant
    Filed: February 27, 1990
    Date of Patent: October 26, 1993
    Assignee: Motorola, Inc.
    Inventor: Dennis R. Schaeffer
  • Patent number: 5251328
    Abstract: The problem of noise enhancement is eliminated in communications systems by predistorting the amplitude of the transmitted information signal in a manner which compensates for the amplitude distortion introduced in a portion of the communications channel. In the disclosed embodiments, the communications system includes two signal transceivers which communicate with one another through a communications channel. The communications channel includes two-wire subscriber loops adjacent to each signal transceiver with a four-wire transmission path disposed between the subscriber loops. Each transceiver transmits an information signal which, depending on the system noise characteristics, is predistorted to compensate for all or a portion of the amplitude distortion introduced in a subscriber loop adjacent to that signal transceiver. The predistortion necessary to provide such compensation is determined at each transceiver in response to received signals at that transceiver.
    Type: Grant
    Filed: December 20, 1990
    Date of Patent: October 5, 1993
    Assignee: AT&T Bell Laboratories
    Inventor: David G. Shaw
  • Patent number: 5251330
    Abstract: This invention relates to a linear transmitter which controls the bias voltage of either the drain electrode or collector electrode of an amplifier for radio frequency based on the envelope of the modulated signal, and is characterized in that it controls the bias voltage of the radio frequency amplifier in digital arithmetic processing by generating the envelope using in-phase envelope component and quadrature envelope component obtained from the base band signals.
    Type: Grant
    Filed: April 19, 1991
    Date of Patent: October 5, 1993
    Assignee: Nippon Telegraph & Telephone Corporation
    Inventors: Kouji Chiba, Toshio Nojima, Yasushi Yamao, Shigeru Tomisato, Tadao Takami
  • Patent number: 5247704
    Abstract: A cordless telephone handset includes a burst mode transmitter/receiver unit comprising a radio (10) and a current sink (20) shunted across the radio. A controller (18) controls the current sink (20) in a feedback manner such that the sum of the currents drawn by the radio and the current sink is substantially constant, in order to compensate for fluctuations in the current drawn by the radio alone, so as to avoid interference at the burst rate when the handset is used in conjunction with a hearing aid.
    Type: Grant
    Filed: June 27, 1990
    Date of Patent: September 21, 1993
    Inventor: Martin Greenwood
  • Patent number: 5247701
    Abstract: Shown, herein, is a method of allowing use of small, low-power communication systems within the service coverage area of larger trunked systems. The small, low-power systems are constructed to reuse at least some of the communication resources, also used by the larger system. The large system measures signal strength values of large cell communication units and transfers such values to the small systems. A small system compares the transferred values with a threshold and when the threshold is exceeded, reuses the communication resources under a TDM format within the small system.
    Type: Grant
    Filed: June 29, 1990
    Date of Patent: September 21, 1993
    Assignee: Motorola, Inc.
    Inventors: Richard A. Comroe, Arun Sobti, Paul M. Bocci, Robert W. Furtaw, Bradley M. Hiben, James A. McDonald
  • Patent number: 5243415
    Abstract: A stereo-audio video limited range low power RF transmitter to receiver system is provided transmitting signal from a video cassette recorder (VCR), satellite converter, TV camera, cable select box and a TV receiver/monitor, or VCR, utilizing a wireless signal path retaining signal quality normally associated with conventional wiring. Two-channel stereo-audio is passed via two independent audio channels matched to selected video channels for combined short range RF transmitter to receiver transmission to one or more television sets and/or VCR sets in different rooms, with at times display and/or recording simultaneously the same transmitted program from the transmitter of the system.
    Type: Grant
    Filed: April 5, 1991
    Date of Patent: September 7, 1993
    Assignee: Primo Microphoes, Inc.
    Inventor: R. Edward Vance
  • Patent number: 5241697
    Abstract: An FM receiver includes an IF unit followed by an LF unit. The receiver has circuitry for changing the signal transmission characteristic of the IF and/or LF units, including a detector module with detector circuits for detecting values characteristic of receiving or interference states, with the inputs of these detector circuits each being connected with a circuit point of the IF or LF unit carrying the signal to be processed and with the outputs of these detector circuits providing signal characterizing receiving the interference states.
    Type: Grant
    Filed: October 29, 1990
    Date of Patent: August 31, 1993
    Assignee: H.u.C. Elektronik GmbH
    Inventor: Jens Hansen
  • Patent number: 5241701
    Abstract: An antenna selecting diversity receiving apparatus utilizes linear modulation with information about the envelope of a modulating wave included therein and is employed in a radio communication system using TDM. An integrating circuit serves to integrate electric-field levels received by respective antennas over a predetermined period of time before a start in a time slot allotted to a radio receiver. Then, a comparing circuit makes a comparison among respective time-integrated values corresponding to the respective antennas. In addition, a changeover control circuit serves to select an antenna corresponding to the maximum time-integrated value as the antenna used during the period of the time slot allotted to the radio receiver.
    Type: Grant
    Filed: April 26, 1991
    Date of Patent: August 31, 1993
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Akira Andoh
  • Patent number: 5239680
    Abstract: Authentication of system status OSWs in a trunked communication system is provided by first verifying (411) that a received system ID (313) matches a pre-programmed system ID. A system status OSW must then be matched twice before the information in the system status OSW is programmed into a communication unit (115), thus limiting the possibility of false decoding of system status OSWs.
    Type: Grant
    Filed: March 26, 1991
    Date of Patent: August 24, 1993
    Assignee: Motorola, Inc.
    Inventors: Gary W. Grube, Michael D. Sasuta
  • Patent number: 5230077
    Abstract: In a receiving circuit of a mobile telephone apparatus the incoming baseband signals are demodulated and equalized so as to compensate for deficiencies (multipath propagation) of the radio medium between base station and mobile telephone apparatus. It is not, however, always necessary to equalize the demodulated signals, for instance at low symbol rates or in the case of monopath propagation. According to the invention, time dispersion of the received signals is estimated prior to demodulation, and demodulation with equalization (3a) is effected when the time dispersion is established to be higher than a given value, whereas demodulation without equalization (3b) is effected when the time dispersion is lower than this value. This will enable the power consumed by the receiving circuit to be reduced, particularly in the listening mode of the apparatus.
    Type: Grant
    Filed: July 27, 1990
    Date of Patent: July 20, 1993
    Assignee: Telefonaktiebolaget L M Ericsson
    Inventor: Alex K. Raith
  • Patent number: 5220682
    Abstract: An automatic broadcast wave tuning device for a RDS receiver includes a controller to enforce the RDS receiver to receive the former broadcast wave by setting a forbidden flag under such conditions as being unable to receive a program identification code when a receiving signal level of the broadcast wave within the same broadcasting network is above a predetermined signal level, or in the case of being able to receive the program identification code when failing to meet up with that of the broadcasting station presently in contact. Hence, from the next automatic receiving frequency tuning, a control is provided for setting a frequency divisional ratio of the phase-locked loop circuit in order to select the best broadcast station of all by discriminating reception signal levels of the broadcast waves transmitted by all the broadcasting stations bearing no forbidden flag.
    Type: Grant
    Filed: September 26, 1991
    Date of Patent: June 15, 1993
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Ryou Tomohiro
  • Patent number: 5220686
    Abstract: An amplifier with a non-regenerative DC negative feedback loop which incorporates first and second first-order low-pass RC filters, has a signal path arranged from an input to an output and a feedback path arranged from the output to the input, and has a controlled loop gain. To provide substantially even selective amplification over a comparatively large tuning control range, the signal path incorporates one of the two RC filters and the feedback path incorporates the other RC filter together with the controlled loop gain; or the signal path incorporates the two RC filters together with one part of the controlled loop gain and the feedback path incorporates the other part of the controlled loop gain.
    Type: Grant
    Filed: December 20, 1990
    Date of Patent: June 15, 1993
    Assignee: U.S. Philips Corporation
    Inventors: Wolfdietrich G. Kasperkovitz, Hendricus C. De Ruijter
  • Patent number: 5218715
    Abstract: A system and method for handing back a movable transceiver to a different cell site from the original cell site includes circuitry for sensing signals from the movable transceiver which are transmitted on a modified frequency as well as circuitry for translating those signals back to their originally assigned frequencies without changing the detected field strength of the signal, in combination with circuitry for forwarding the translated signals to the different cell site for hand-off evaluation. The method includes sensing the received signals, translating the received signals to an originally assigned frequency based on either a fixed offset or other provided information concerning the translation along with a step of continually updating those frequencies which are to be retranslated.
    Type: Grant
    Filed: January 15, 1991
    Date of Patent: June 8, 1993
    Assignee: Orion Industries, Inc.
    Inventors: Samuel A. Leslie, William A. Bowen, Michael W. Evans
  • Patent number: 5212823
    Abstract: In a radio communication system, a base station transmits a signal including a component which designates a power level. A mobile station receives the signal from the base station. In the mobile station, an output power of the mobile station is set to the designated power level, and a field level of the received signal transmitted from the base station is detected. A determination is made as to whether or not the detected field level of the received signal is equal to or higher than a predetermined field level. The output power of the mobile station is decreased from the designated power level by a predetermined value when the detected field level of the received signal is equal to or higher than the predetermined field level.
    Type: Grant
    Filed: February 12, 1990
    Date of Patent: May 18, 1993
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Yuichi Fujii, Tetsuaki Nakanishi