Ericsson Gmbh

Ericsson Ge Mobile Communications Inc.

Research Triangle Park

Smd Software, Inc.

Ross W Lampe, Jr

Paul W Dent

Rodney A Dolman

Paul Wilkinson Dent

Gregory Edward Bottomley

Antonio J Montalvo

William Oscar Janky

Philip C Gulliford

Anthony B Waldroup

Xue-Song Zhou

Scott H Ollett

Claes Henri Von Sheele

Jyun-chen Chen

John T Gillette

Clayton F Helvey

Satish Kappagantula

A method and apparatus for curing photosensitive materials uses LEDs and an optical concentrator to generate high optical power intensities. An LED array, comprising a plurality of LED assemblies, generates collimated light. A collection lens functions as an optical concentrator and focuses the collimated light to a desired spot size at a desired location. The LED assemblies may be at least partially disposed in a cooling plenum, where the cooling plenum is at least partially defined by the collection lens. Each LED assembly within the LED array may be detachably coupled to a mounting surface, enabling easy replacement of individual LED assemblies within the LED array. The photocuring assembly may also include a redirecting assembly disposed between the collection lens and the desired location that may further concentrate the light at the desired location. The photocuring assembly may include more than one of the above features.

High intensity photocuring system

In a receiver for receiving data samples including a sequence of symbol values transmitted across the channel, a baseband processor including a first hypothesize unit developing first sets of hypothetical symbol values, a second hypothesize unit developing second sets of hypothetical symbol values different from the first sets, a parameter estimator receiving the received data samples and the first and second sets of hypothetical symbol values and developing parameter estimates based thereon, and a sequence estimator receiving the developed parameter estimates, the first sets of hypothetical symbol values and a delayed version of the received data samples and developing a sequence of detected symbol values related to the received data samples.

Baseband processor with look-ahead parameter estimation capabilities

A simplified structure is disclosed for a dual-band, double-conversion superheterodyne receiver. All mixer-injection signals are generated by combining the outputs of two phase-locked frequency synthesizers driven by a single reference oscillator. The output of one synthesizer injects the receiver's second mixer, which converts signals from the first intermediate frequency to the second intermediate frequency. The output of the other synthesizer has two uses: (1) it provides first mixer injection needed to tune the receiver to a primary band, and (2) it is mixed with the output of the first synthesizer to provide the first mixer injection needed to tune the receiver to an alternate band.

Dual-band radio receiver

A high dynamic range receiver IF system using limited dynamic range IF filters is disclosed. A variable gain amplifier amplifies a first IF signal. The amplified first IF signal is then applied to an image suppression mixer for suppressing an image component of the amplified first IF signal to provide adequate image suppression for a radio system, wherein the image suppression mixer outputting an image suppressed second IF signal. An active bandpass filter then filters the unwanted components from the second IF signal. The filtered signal is then hard limited in a limiting amplifier which outputs a limited IF signal. A logarithmic detector then provides a received signal strength indicator.

Receiver IF system with active filters

In a trunked radio communications system, apparatus and methods are provided for transparently updating existing frequency division multiple access (FDMA) communications facilities to accommodate time division multiple access (TDMA) communications. TDMA channels are added to existing FDMA sites on an individual basis to increase spectral efficiency and capacity while still being compatible with existing FDMA equipment and protocols. For example, the existing FDMA control channel and protocols are used by dual mode sites and dual mode radios. A dual mode radio transceiver selectively participates in trunked radio communications in either an FDMA mode or in a TDMA mode. Each dual mode radio includes a memory for storing a mode identifier identifying each channel as an FDMA or a TDMA working channel. When a channel assignment is made, the dual mode radio determines from that channel mode identifier stored in memory whether to operate in the FDMA or TDMA mode for that particular communication. Moreover, dual mode radios expedite synchronization to a TDMA working channel (time slot) using a timing relationship established between the FDMA control channel and the TDMA working channels. In the context of multiple site, trunked radio communications, the present invention provides for interoperability between sites and radios which have TDMA communications capabilities and sites and radios which have only FDMA capabilities.

Trunked radio frequency communication system for accommodating both

Reduction of transmitter exciter chain generated noise from the receive bank of a portable/hand-held duplex transceiver is achieved using a high output power, low-noise voltage-controlled-oscillator (VCO) in the transmitter exciter chain. Using this high-power, low-noise oscillator as the RF source in the transmitter exciter chain precludes the need for the conventional buffer/driver amlplifier stage and an associated inter-stage noise filter. Elimination of buffer/driver stage components and bulky inter-stage noise filter components allows complete integration of transmitter exciter chain components resulting in reduced size and cost.

Method and apparatus for reducing receive band transmitter-chain noise

A method of mass producing printed circuit antennas is disclosed including the steps of providing a substrate of dielectric material having a first side and a second side, removing portions of the substrate to produce an array of interconnected segments of desired size, fabricating a main radiating element on the first side of each substrate segment, overmolding each substrate segment with a protective dielectric material, and separating each substrate segment from the dielectric substrate to form a plurality of individual printed circuit antennas. Preferably, each of the foregoing steps are able to be performed on each substrate segment substantially simultaneously. The method may also include the steps of freeing one end of the substrate segments, attaching an electrical connector to each substrate segment, and overmolding the electrical connector for each of the substrate segments prior to the separating step. Fabrication of additional radiating elements to the first or second side, or alternatively a reactive or parasitic element to the second side, may be undertaken so that the printed circuit antennas are capable of multi-band operation.

Method of mass producing printed circuit antennas

An amplifying apparatus for linearly amplifying a desired signal using a pair of coupled non-linear amplifiers is disclosed. The amplifying apparatus comprises a limiter for separating amplitude variations from the desired signal and producing a constant amplitude signal bearing the phase of the desired signal and an amplitude related signal. In addition, a drive signal generater produces two drive signals each dependent on the constant amplitude signal and the amplitude related signal such that each drive signal depends on the phase of the desired signal and such that the sum of the squares of the amplitudes of the drive signals is constant. Finally, a coupler couples the two drive signals to produce two constant amplitude signals for driving the pair of non-linear power amplifiers and for coupling the outputs of the power amplifiers to produce two amplified output signals, one of which is the linearly amplified desired signal and the other of which is a waste energy signal.

Waste energy control and management in power amplifiers

Continuous phase modulated (CPM) signals, such as quaternary CPFSK signals, are filtered to limit their bandwidth while simultaneously minimizing the amount of amplitude modulation and intersymbol interference introduced by this filtering process. By designing a modulation filter such as a finite impulse response (FIR) filter to add only a nominal, controlled amount of amplitude modulation, high efficiency, nonlinear power amplifiers may be employed to transmit the filtered CPFSK signals. Although the filter adds a small amount of amplitude modulation and intersymbol interference, digital signal processor-based receivers satisfactorily demodulate this type of signal using sequence estimation algorithms such as the Viterbi algorithm. Thus, the filtering of CPM signals permits narrowing of the transmitted signal spectrum while managing the intersymbol interference resulting from the controlled amount of amplitude modulation added by filtering. Narrowed bandwidth along with high efficiency, nonlinear power amplifiers make the present invention particularly well suited to narrowband mobile radio communications.

Digital modulation method with controlled envelope variation

In half-duplex, trunked digitized voice communications between mobile transceivers, the present invention minimizes time delays occurring after one transceiver ends a transmission and before other transceiver communications may commence. A disconnect signal is transmitted from the currently transmitting transceiver during a time frame immediately following indication that a current communication has ended. Channel access time delays are minimized by permitting speech input to a transmitting transceiver immediately upon receipt of a working communications channel. The present invention has particular applicability in trunked TDMA radio communication systems.

System and method for radio disconnect and channel access for digitized

Waste energy control and management in power amplifier

A phase-locked loop incorporates a quadrature modulator for generating constant envelope phase or frequency modulation. Locating the quadrature modulator within the feedback loop or feeding the output signal of the quadrature modulator into the feedback loop permits accurate constant envelope phase modulation of the loop reference oscillator and completely suppresses undesired AM and PM components of the modulated signal.

Growing community of inventors

Raleigh, NC, United States of America

Ross W Lampe, Jr