摘要:
A feedforward linearizer for amplifying an input signal comprises a signal cancellation circuit which has a first branch and a second branch. A first amplifier provided in the first branch receives the input signal intended to be amplified and generates an output signal received by a signal cancellation vector modulator. A signal cancellation adder receives the signal generated by the signal cancellation vector modulator and the input signal via the second branch and provides an error signal. The feedforward linearizer also comprises an error cancellation circuit that has a first branch and a second branch. An error cancellation adder in the first branch receives the output signal provided by the first amplifier and generates the output signal of the linearizer. An error cancellation vector modulator in the second branch receives an error signal provided by the signal cancellation adder and provides an error adjusted signal to a second auxiliary amplifier. The second auxiliary amplifier provides an input signal to the error cancellation adder. A digital signal processor provides a signal cancellation adjustment signal, .alpha., to the signal cancellation vector modulator and an error cancellation adjustment signal, .beta., to the error cancellation vector modulator respectively, such that the output signal of the signal cancellation adder is a signal that substantially represents the error components provided by the first amplifier, and the output signal of the error cancellation adder is an amplified version of the input signal, with substantially no internmodulation components.
摘要:
An indoor wireless communications system using two-way active-antenna repeaters to distribute signals received from external signal sources within an office, and to extend the range of cordless phone units in use there, is disclosed. The repeaters provide menu-selectable phase-shifting, selectable receiver sensitivity and transmitter power, and selectable signal format conversion to provide added privacy and to prevent interference with communication links in use by third parties within the building. Pattern selection is done by empirical adjustment of an antenna pattern suited to the general floor plan of the area served.
摘要:
A system, e.g. for optical communication, includes an I-Q modulator and a transmission signal processor. The I-Q modulator is configured to modulate a first light source in response to first I and Q modulation signals. The transmission signal processor is configured to receive a data stream including data corresponding to a first data subchannel. The processor maps the data subchannel to an optical transmission subchannel and outputs the first I and Q modulation signals. The I and Q modulation signals modulate the light source to produce an optical transmission signal that includes wavelength components corresponding to the optical transmission subchannel.
摘要:
A device includes a passive photonic layer located over a substrate and including at least one passive photonic element configured to propagate an optical signal therein. An electronic layer located between said substrate and said passive photonic layer includes at least one electronic device configured to propagate an electrical signal therein. An active photonic layer located over said passive photonic layer includes an active photonic device optically coupled to said passive photonic element and configured to convert between said electrical signal and said optical signal.
摘要:
The present invention provides an optical beamforming RF transmitter. In one embodiment, the optical beamforming RF transmitter includes an optical WDM splitter having an input and a plurality of outputs. The optical beamforming RF transmitter also includes an array of antennas, where each antenna has an optical input configured to drive the corresponding antenna, and an array of optical modulators, such that each modulator has an output connected to a corresponding one of the antennas and an input connected to one of the outputs of the optical WDM splitter. The optical beamforming RF transmitter further includes a mode-locked laser having an output optically coupled to the input of the optical WDM splitter.
摘要:
An apparatus includes an electronic amplifier and an electrical feedback line, a plurality of electrical sources, and an electronic controller. The electrical feedback line connects an output of the electronic amplifier to an input thereof. The electrical sources connect to nodes on the electronic feedback line. The electronic controller is configured to adjust the electrical sources in a manner responsive to a current input to the electrical feedback line.
摘要:
An apparatus includes an electronic amplifier and an electrical feedback line, a plurality of electrical sources, and an electronic controller. The electrical feedback line connects an output of the electronic amplifier to an input thereof. The electrical sources connect to nodes on the electronic feedback line. The electronic controller is configured to adjust the electrical sources in a manner responsive to a current input to the electrical feedback line.
摘要:
An electronic device includes a first strip conductor formed from a first metal level over a substrate. A second strip conductor formed from a second metal level is located between the first strip conductor and the substrate. At least one of the first and the second strip conductors includes a stripline portion and a microstrip line portion.
摘要:
A self-calibrating integrated photonic circuit and a method of controlling the same. In one embodiment, the circuit includes: (1) a substrate, (2) a laser located on the substrate and configured to produce source light at an output frequency, (3) a laser alignment sensor located on the substrate and including: (3a) a reference optical resonator configured to receive the source light, have a null proximate a predetermined center frequency and provide output light as a function of a relationship between the output frequency and the center frequency and (3b) a photodetector configured to provide an electrical signal of a magnitude that is based on the output light and (4) a calibration controller located on the substrate, coupled to the photodetector and configured to adjust the output frequency based on the magnitude.
摘要:
An optical digital-to-analog conversion is realized by employing either a continuous wave or pulsed laser optical signal. The laser optical signal is split into a plurality of mutually coherent optical beams, which are phase shift modulated by bits of a digital data sequence to be converted to an analog signal. The phase shift modulated optical beams are recombined to realize the desired digital-to-analog converted optical signal.