Abstract: A personal communicator for use in a wireless communication network includes a wireless communications LCD and a multimedia LCD with the communications, mounded on a hinged member, and superimposed on top of the multimedia LCD. The communications LCD is sufficiently transparent to permit viewing of the under multimedia LCD. Each provides visual information to the user relative to the present use of the communicator. The selected use of the communicator is primarily responsive to the open or closed position of the hinged keyboard supporting cover. When the hinged member is closed the communicator operates in a communication mode. When it is open the communicator operates primarily in a multimedia mode. The personal communicator includes a steerable video imager for controllably optimizing image field coverage and adjusting to the orientation of the user relative to the personal communicator.

Abstract: A universal wireless radiotelephone communication apparatus is operative in both a first radiotelephone communication system including a first base station having a wide area of coverage, transmitting radiotelephone signals at a first band of frequencies and in a second radiotelephone communication system including a second base station having a localized area of coverage, transmitting radiotelephone signals at a second band of frequencies higher than said first band of frequencies. The second band of frequencies is optimally selected with an offset of less than twice a frequency contained within said first band. The wireless radiotelephone communication apparatus has a common baseband circuitry for operating with both the first base station covering the wide area and with the second base station covering the local area.

Abstract: A channel assignment system assigns channels to various cells by the optimal partitioning of the available radio frequencies into non-overlapping sets, the optimal grouping of co-user cells, and the best assignment of the former to the latter. The objective is the maximization of traffic handling capacity which, given the multitude of cells, is expressed as the maximization of a bottleneck capacity ratio. The capacity ratio for a cell is defined as the ratio of the number of radio frequencies assigned to the cell over the number of radio frequencies needed to meet blocking probability requirements. The solution to attain an optimal non-regular channel assignment is decomposed into two mathematical programs designated a Master Program and a Subprogram. These are solved iteratively with assistance from a channel set augmentation technique impelmented between solutions of the Master and Subprogram.

Abstract: A power factor control system for a rectifier is operative through the generation of estimators of control input parameters (a peak squared input AC voltage E.sub.m.sup.2 and load power) and by the use of these substantially ripple free signals controls a boost, buck, buck-boost, SEPIC or other related type converter at the input to the rectifier. The generation of these parameters allows the derivation of a programmed current i.sub.p used to control the wave form of the actual input current. The control procedure is based on a quarter cycle averaged power basis. The input power is derived from the rms values of the input voltage and current. Given the output power and its deviations in power due to load changes, the programmed current i.sub.p is determined by deriving an input conductance of the rectifier and combining it with the input voltage.

Abstract: A new insulation system comprising film coated, copper magnet wires covered under NEMA Standards No. MW1000, insulated with single or multiple layer(s) of extruded TEFLON.RTM. (any color) fluorocarbon resin insulation to meet the government or safety agency promulgated performance and construction requirements.

Abstract: A digital block receiver system, in a cellular/wireless FM radiotelephony system, receives and heterodyne a block of cellular/wireless receive channels to a very low block IF signal by analog processing. This block IF signal is applied to a precision high speed A/D converter and converted to a digitized time series. A window function is applied to the digitized time series and a high speed FFT is applied to frequency isolate the individual channels. The active channels are digitally processed by a DSP to recover the FM channel modulation.

Abstract: A power converter circuit requiting the periodic reset of a core of the power transformer includes a control circuit operative to alter a response of the converters voltage regulation feedback control to limit and/or control the power switch duty cycle to regulate a voltage of the reset capacitor whenever the reset capacitor sustains a voltage above a preset threshold.

Abstract: A half bridge power converter utilizes two oppositely phased power switches operated with unequal duty cycles. A magnetic arrangement with two inductance values having a ratio equal to the ratio of the unequal duty cycles is included in the converter to compensate for the unequal duty cycles.

Abstract: Magnetic components are fabricated as monolithic structures using multilayer co-fired ceramic tape techniques. Fabrication of these magnetic components involves constructing multiple layers of a magnetic material and an insulating non-magnetic mataerial to form a monolithic structure with well defined magnetic and insulating non-magnetic regions. Windings are formed using screen printed conductors connected through the multilayer structure by conducting vias.

Abstract: A method for enabling the service of mobilies by a microcell, in a two tier cellular system, involves identifying a microcell coverage area and offsetting microcell signal strength for a time sufficient to allow a fast moving vehicle, desiring service and having entered the microcell serving area, to exit the microcell coverage area before the call is set up or handed off forcing the controlling macrocell to handle the call setup or hand-off. Hence, only the mobile radiotelephones of stationary and relatively slow moving vehicles are served by the microcell. There is a substantially offset-coverage overlap period between the locations where a mobile may be found during the offset interval or duration of the apparent reduced signal strength of the microcell and the microcell coverage area. Calls that could be serviced by the microcell are instead serviced by the macrocell because the mobile radiotelephone responds to the strongest signal. This loss in capacity is solved by reducing the offset-coverage overlap.

Abstract: Phototools are located for processing both sides of printed circuit board panels by an apparatus and process that utilizes a work station with two alignment fixtures each including panel center registration PCR alignment mechanism to locate phototools and panels. Processing steps utilize the alignment fixtures to locate phototools on both sides of a panel. Each of the two phototools is initially positioned on its alignment fixture by the PCR alignment mechanism and secured to its alignment fixture by means of a vacuum supplied by a vacuum chuck which is operative as the top surface of the alignment fixture. The panel is then placed on top of the first phototool and aligned to the first phototool in the first alignment fixture using the PCR alignment mechanism. This first phototool is then affixed to the first side of the panel.

Abstract: A DC-DC converter utilizes a tapped transformer secondary winding as a means of achieving output voltage ripple cancellation. This ripple cancellation occurs at a specified input voltage. It operates by fixing the location of a tap on the secondary winding of the power transformer so that the output voltage ripple cancellation occurs at the specified input voltage. It also minimizes the volt seconds that must be sustained by the output filter inductor over a specified range of input voltage for the converter.

Abstract: A common mode lightning protection circuit includes a series circuit including a Y-capacitor and breakdown device connected between a current carrying input line and the frame ground of the power supply. This arrangement permits the ready application of current carrying line-to-frame ground dielectric tests needed to meet predefined safety requirements.

Abstract: A reduced-voltage/zero-current transition (RV/ZC-T) PWM converter includes an added active resonant network shunting the active power switch to reduce the switching losses in both the active power and and passive rectifier switches. The active power switch turns-on under reduced-voltage while the rectifier diode turns-off under zero-current. A soft current turn-off of the rectifier makes this converter suitable for high voltage applications where the reverse recovery losses of the diode can be considerable. An auxiliary switch included in the resonant network also operates with zero-current- switching.

Abstract: A drive arrangement and operative scheme for the power switching transistors of a half-bridge power drives the two power switching transistors with unequal duty cycles having conducting durations such that the sum of the conduction intervals substantially equals the combined switching period of the two power switching transistors. The conducting intervals are separated by very short dead time intervals controlled by the differing turn-on and turn-off times of the two power switching transistors. The short interval between alternate conductions of the two power switching transistors is sufficient to allow zero voltage turn on of the power switching transistors but short enough to minimize power loss and conducted noise.

Abstract: Therefore a method and apparatus for controlling a linear amplifier processing a plurality of carrier signals of a multi channel carrier system alters the phases of one or more sources of the multi-channel signals in response to a detected peak envelope power or of a peak to average power ratio at regular scheduled intervals. This reduces the peak envelope power to average envelope power ratio and enables the reduction in the power rating required by the amplifiers handling the multi-channel signal.

Abstract: A synchronous rectifier for use with a clamped-mode power converter uses in one embodiment a hybrid rectifier with a MOSFET rectifying device active in one first cyclic interval of the conduction/nonconduction sequence of the power switch and a second rectifying device embodied in one illustrative embodiment as a low voltage bipolar diode rectifying device active during an alternative interval to the first conduction/nonconduction interval. The gate drive to the MOSFET device is continuous at a constant level for substantially all of the second interval which enhances efficiency of the rectifier. The bipolar rectifier device may also be embodied as a MOSFET device. The subject rectifier may be used in both forward and flyback power converters.

Abstract: In plural channel amplifier systems processing many phase locked signals of different frequencies as a combined signal, these signals may drift into a phase convergence causing a peak power occurrence in the amplifier which greatly exceeds the rated capacity of the amplifier system. Therefore, in accord with the invention, a dynamic adjustment system is provided to minimize the peak power to which the amplifier is subjected by adjusting the relative phase relationships of the many signals. The dynamic adjustment system includes a peak power detector, a hard wired logic decision circuit and a timing control to control phase shift adjustment steps.

Abstract: Remote downloading of number assignment module designation parameters into a read-only memory circuit of a wireless telephone subscriber set (e.g., mobile, cordless, etc.) can be achieved by incorporating a tone signals receiver into the set and by bridging the receiver onto a wireless voice communication channel established between the subscriber's set and a service representative. The service representative can remotely enter subscriber-specific programming information and wireless service authorization data into the subscriber's telephone set for storage therein thereby quickly, reliably and cost-effectively providing authorized service to a new subscriber, or to an existing subscriber who requests a service change.

Abstract: Downloading of number assignment module designation parameters into a memory circuit of a mobile data telephone set utilizes the built-in voice band modem of the set so that service authorization codes and activation can be entered remotely into the subscriber's set thereby initiating cellular service or changing the type of service provided. As described, a cellular mobile subscriber first calls a remote cellular service provider center to establish a voice communication channel between the set and the center. Next, the modem of the set is selectively bridged onto the voice communication channel to achieve data transfer between a source of data located at the remote center and the subscriber's modem. The foregoing enables the remote programming of subscriber's authorization and information into the memory circuit of the mobile data telephone set.