The Boeing Company

John H Nitardy

David K Brown

Robert Paul Higgins

Rodney Alan Hughes

Rodney Kevin Bonebright

Jay W Clement

Ken Y Ogami

John C Oberholtzer

A transceiver (14) for recovering two different types of manchester coded, optical data signals from a photodiode is disclosed. The transceiver (14) includes a preamplifier (28) that receives and differentially amplifies the optical signal to reject power supply noise. The output of the preamplifier (28) is applied to an AC coupler (30) that extracts DC signal components using a switching circuit to produce a purely differential signal. A post amplifier/quantizer (34) receives the purely differential signal from the AC coupler (30) and generates a quantized signal therefrom. The quantized signal is applied to a data filter, clock recovery and control logic system 36 (36) that recovers a clock signal from the data signal that is synchronized by every data edge of the quantized signal.

Dual rate, burst mode, radiation hardened, optical transceiver

An adaptive power control used on a radio network and a method for adaptively controlling the transmit power level of member stations on the network. An exemplary network (12) includes a plurality of member stations (10a through 10f) between which radio signal propagation conditions are subject to change. Each member station includes a transceiver (21) having a transmitter (26) and a receiver (28) section. The transmit power level of the transmitter is controlled by a variable gain circuit (48) in response to a variable gain signal produced by a control (34). A member station uses a transmit power level determined by reference to a database in which signal-to-noise ratio (SNR) data defining the quality of each communication link and the transmit power levels last used for communication between each pair of member stations of the network are stored. If a response to a transmission in an initial frame is not received in the next frame, a controlling member station (server) incrementally increases its transmit power level by P.sub.D in successive frames, until either a response is received or the member station has failed to respond to a transmission at a maximum transmit power level, P.sub.max. If the response indicates that the signal is received with an SNR in excess of a predetermined margin, the server reduces its transmit power level to ensure that the minimum transmit power is used.

Apparatus and method for controlling transmitted power in a radio network

A high-efficiency amplifier (10, 18) that may be used in, for example, a radar system to amplify signals received at an exciter (22) before they are applied to an antenna (20). The amplifier includes, among other components, an adaptive matching network (48) that is controlled by a processing system (26) to allow the amplifier to be adaptively matched to the load as the operating frequency of the system undergoes changes. Specifically, the network is adjusted based upon information regarding the ratio R of reflected power over incident power measured at the load the last time the system operated at the same frequency. As a result, the system is able to respond more quickly to frequency changes.

High efficiency power amplifier

A networked radio communication system for transmitting a radio signal between a source transceiver and a plurality of destination transceivers. The source transceiver first transmits an interrogate signal that includes a synchronize code and an address code that is indicative of a particular destination transceiver. If the particular destination transceiver receives the interrogate signal, an acknowledge signal that includes the address of the destination transceiver that is transmitting the acknowledge signal is transmitted back to the source transceiver. The source transceiver compares the address included in the interrogate signal with the address included in the received acknowledge signal and determines if a communications link is established. If a communication link is established, a feedback signal is provided to the operator of a source transceiver indicating that the source transceiver is in communication with the particular destination transceiver. The feedback signal preferably includes a sidetone signal which allows an operator of the source transceiver to monitor signals transmitted from the source transceiver to the plurality of destination transceivers.

Radio communication system including indication that communication link

Apparatus and a method for transmitting a direct sequence, spread spectrum communication system signal. A transmitter (10) that receives a variable data rate information bearing input signal from a digital data source (12) includes a forward error correction encoder (80) that provides redundancy and an interleaver (82) that rearranges the input data. The forward error correction encoder and interleaver minimize the effect of errors that arise in the propagation of the transmitted signal. The output of the interleaver is applied to the input of a Hadamard encoder (84), which converts data words from the interleaver into one of N orthogonal codes, producing a Hadamard signal that varies at a bit rate that changes as the data rate of the information bearing signal varies. A pseudorandom number code generator (16) produces a code signal comprising a pseudorandom sequence of chips supplied at a constant chip rate. The Hadamard signal is input to a direct sequence (DS) modulator that modulates the information bearing signal with the code signal, using an integer number (greater than one) of chips to modulate each bit of the Hadamard signal. As the data rate of the information bearing signal varies, the number of chips per bit of the Hadamard signal is varied so as to minimize variations in the chip rate of the DS modulated signal. The transmitter is preferably combined with a receiver (29) in a transceiver. The receiver demodulates a received signal, and correlates it with a code signal from a pseudorandom number code generator (40) corresponding to the pseudorandom number code generator in the transmitter. The receiver also includes a Hadamard decoder (94), deinterleaver (96), and forward error correction decoder (98). A frequency hopping capability is optionally provided.

Multi-rate spread system

Disclosed is a frequency mapping system (10) including a data processor (12) and a control word memory (16) to be used with a pseudo-random (PN) number generator (32) and a frequency synthesizer (34). The processor receives an input that specifies those frequencies in a frequency band that are available for communications, associates each specified frequency with a respective control word that designates a carrier frequency to the frequency synthesizer, and stores the control words corresponding to the specified frequencies in the control word memory. Once the control word memory is mapped, the PN generator produces code words that address locations in the control word memory whereby the control words in the addressed locations are sent to the frequency synthesizer.

Frequency hopping method and apparatus

A sweep linearization network for an FM/CW radar system, wherein the transmitter sweep rate is subject to variation as a function of range, is comprised of a sweep slope circuit for establishing a desired sweep rate for the interrogation signal of the radar transmitter; an accumulator/memory having stored therein a plurality of sweep slope coefficients corresponding to N discrete sweep segments of an individual sweep of the interrogation signal; a driver for developing a ramp signal controlling the sweep of the interrogation signal, which receives the sweep slope signal and, sequentially, the sweep slope coefficients for adjusting the ramp signal over each of the N sweep segments; a transmitter sampling circuit for developing a transmitter characteristic signal proportional to and indicative of the interrogation signal; a discriminator for dividing the transmitter characteristic signal into a plurality of equal frequency excursion time periods based upon a preselected amplitude thereof to develop a measured time signal proportional to and indicative of the frequency versus time relationship of the interrogation signal; a timing circuit for establishing N equal time periods over the duration of a single sweep to develop a comparison time signal; and a processor for comparing the measured time signal for the selected segment with the comparison time signal to develop an error signal proportional to and indicative of any sweep slope error over a corresponding time segment N.sub.i ; wherein the error signal is applied to the accumulator/memory circuit for updating the respective sweep slope coefficient and thereby sequentially linearize the sweep as a consequence thereof.

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Seattle, WA, United States of America

John H Nitardy