An antenna arrangement (10) for a cellular radio base station is provided with a plurality of r.f. transceivers, including one or more antenna arrays (12) each comprising a plurality of sub-arrays (20) each selectively operable to form a beam in azimuth. Each sub-array is provided with elevation beamforming means (24) and individual transmit and receive amplifiers (30,32). Each sub-array beamformer is coupled to at least one r.f. transmitter feed (26)nd each r.f. receiver feed is coupled to at least two sub-array beamformers, the sub-arrays of each antenna array together forming a multiplicity of separate substantially coincident beams in azimuth. A method of operation is also disclosed.

Base station antenna arrangement

A method and an apparatus measure blood oxygenation in a subject. A first signal source applies a first input signal during a first time interval. A second signal source applies a second input signal during a second time interval. A detector detects a first parametric signal responsive to the first input signal passing through a portion of the subject having blood therein. The detector also detects a second parametric signal responsive to the second input signal passing through the portion of the subject. The detector generates a detector output signal responsive to the first and second parametric signals. A signal processor receives the detector output signal and demodulates the detector output signal by applying a first demodulation signal to a signal responsive to the detector output signal to generate a first output signal responsive to the first parametric signal. The signal processor applies a second demodulation signal to the signal responsive to the detector output signal to generate a second output signal responsive to the second parametric signal. The first demodulation signal and the second demodulation signal both include at least a first component having a first frequency and a first amplitude and a second component having a second frequency and a second amplitude. The second frequency is a harmonic of the first frequency. The second amplitude is related to the first amplitude to minimize crosstalk from the first parametric signal to the second output signal and to minimize crosstalk from the second parametric signal to the first output signal.

Method and apparatus for demodulating signals in a pulse oximetry system

A MIMO radio transceiver to support processing of multiple signals for simultaneous transmission via corresponding ones of a plurality of antennas and to support receive processing of multiple signals detected by corresponding ones of the plurality of antennas. The radio transceiver provides, on a single semiconductor integrated circuit, a receiver circuit or path for each of a plurality of antennas and a transmit circuit or path for each of the plurality of antennas. Each receiver circuit downconverts the RF signal detected by its associated antenna to a baseband signal. Similarly, each transmit path upconverts a baseband signal to be transmitted by an assigned antenna.

Multiple-input multiple-output radio transceiver

An encoded information reading (EIR) terminal can comprise a microprocessor electrically coupled to a system/data bus, a memory communicatively coupled to the microprocessor, an EIR device, a multi-band antenna, and a wireless communication interface. The EIR device can be provided by a bar code reading device, an RFID reading device, or a card reading device. The EIR device can be configured to output raw message data containing an encoded message and/or output decoded message data corresponding to an encoded message. The wireless communication interface can comprise a radio frequency (RF) front end electrically coupled to the multi-band antenna. The RF front end can comprise a micro-electromechanical (MEMS) filter array including one or more band-pass filter. Each band-pass filter of the MEMS filter array can be electrically coupled to a bias voltage source or an oscillating signal source. The RF front end can be electrically coupled to an analog-to-digital (A/D) converter and/or to a digital-to-analog (D/A) converter. The wireless communication interface can be configured to transmit radio signals in two or more frequency regulatory domains and/or receive radio signals in two or more frequency regulatory domains. The multi-band antenna can in one embodiment be provided by a meta-material antenna.

Encoded information reading terminal with micro-electromechanical radio frequency front end

Transmitter and receiver units for use in an OFDM communications system and configurable to support multiple types of services. The transmitter unit includes one or more encoders, a symbol mapping element, and a modulator. Each encoder receives and codes a respective channel data stream to generate a corresponding coded data stream. The symbol mapping element receives and maps data from the coded data streams to generate modulation symbol vectors, with each modulation symbol vector including a set of data values used to modulate a set of tones to generate an OFDM symbol. The modulator modulates the modulation symbol vectors to provide a modulated signal suitable for transmission. The data from each coded data stream is mapped to a respective set of one or more “circuits”. Each circuit can be defined to include a number of tones from a number of OFDM symbols, a number of tones from a single OFDM symbol, all tones from one or more OFDM symbols, or some other combination of tones. The circuits can have equal size or different sizes. Different circuits can be used for full rate data (e.g., active speech) and low rate data (e.g., silence periods).

Multiplexing of real time services and non-real time services for ofdm systems

A multi-channel digital transceiver (400) receives uplink radio frequency signals and converts these signals to digital intermediate frequency signals. Digital signal processing, including a digital converter module (426), is employed to select digital intermediate frequency signals received at a plurality of antennas (412) and to convert these signals to baseband signals. The baseband signals are processed to recover a communication channel therefrom. Downlink baseband signals are also processed and digital signal processing within the digital converter module (426) up converters and modulates the downlink baseband signals to digital intermediate frequency signals. The digital intermediate frequency signals are converted to analog radio frequency signals, amplified and radiated from transmit antennas (420).

Multi-channel digital transceiver and method

A cellular radiotelephone communication system cell site equipment is provided. The cell site equipment includes a radio frequency transmitter operating as one signal frequency source. In addition, the cell site equipment includes a first and a second signal combiner device tuned to a first and a second signal frequency, respectively. Further, the cell site equipment includes a radio frequency switching mechanism, operatively coupled to the radio frequency transmitter, the first signal combiner device, and the second signal combiner device, for coupling the radio frequency transmitter to either of the first and the second signal combiner devices. In one embodiment, each signal combiner device includes a resonant cavity for isolating a signal frequency source from other signal frequency sources and a coupling for coupling the isolated signal frequency source to a common transmitter output. In an alternative embodiment, each signal combiner device includes a resonant cavity for isolating a signal frequency source from other signal frequency sources and a coupling for coupling the isolated signal frequency source of the first and the second signal combiner device to a first and a second common transmitter output, respectively.

High capacity sectorized cellular communication system

An antenna switching system for handling high traffic sectors in a cellular radiotelephone system. The system switches the cell's base station transmitters (210) to sectors that have more mobile traffic than they can handle. The additional transmitters (210) increase the number of frequencies in the overloaded sector, thereby allowing a greater amount of mobile traffic to use the cell.

Antenna switching system

A digital receiver (200) and a transmitter (300), wherein the digital receiver includes a plurality of antennas (202) for receiving uplink radio frequency signals; a plurality of analog to digital converters (210) for converting the received radio frequency signals into digital signals; a switched digital down converter (214) for down converting one of the digital signals to a baseband IF signal; and a channel processor (228) for recovering one of a plurality of communication channels contained within the baseband IF signal.

Multiple access digital transmitter and receiver

High frequency power transistor carriers are made by bonding a metalized ceramic base to a lead frame strip, subsequently gold plating the resultant structure and then cutting the lead frame strip to isolate the base and collector leads while still maintaining the transistor carriers in strip form. Transistor dice are then attached to each ceramic carrier, and each transistor carrier in the strip is then electrically tested. The individual carriers are then separated from the lead frame strip. The individual carrier has wide base and collector leads extending outward from the ceramic base for a substantial distance and then the base and collector leads are narrowed down. When the individual transistor carrier is used in combination with a hybrid assembly, a reduction in lead inductance and total hybrid package size is obtained while exact carrier placement relative to the hybrid assembly is not required.

John M Smith

Papers

Multi-channel digital transceiver and method

High capacity sectorized cellular communication system

Antenna switching system

Multiple access digital transmitter and receiver

Method of manufacturing RF power semiconductor package