Abstract:
An apparatus having an amplifier and a correction circuit is disclosed. The amplifier may be configured to amplify an intermediate signal to generate an output signal. The amplifier is generally a microwave frequency power amplifier. The correction circuit may be configured to (i) generate a control signal based on a plurality of characteristics of the amplifier, and (ii) adjust a plurality of phases of a plurality of pulses in a pulse burst to generate the intermediate signal. The adjusting may be in response to the control signal. The pulse burst is generally received in an input signal. The phases of the pulses as adjusted in the intermediate signal generally cancel a plurality of phase errors induced by the amplifier in the pulses.
Abstract:
An integrated circuit includes a transmit/receive (T/R) circuit and a gate/drain bias control circuit. The transmit/receive (T/R) circuit may be configured to transmit and receive radio frequency (RF) signals. The gate/drain bias control circuit may be configured to enable or disable internal gate switching of one or more amplifiers of the transmit/receive (T/R) circuit in response to a first control signal. When the internal gate switching is disabled the one or more amplifiers of the transmit/receive (T/R) circuit are enabled and disabled solely by external drain switching.
Abstract:
Systems, circuits, and methods for mixing signals are provided. An illustrative circuit may include mixer circuitry including multiple inputs and at least one output, where the multiple inputs are connected across a local oscillator. The circuit may further include a terminal Radio Frequency (RF) output circuitry that is isolated from the local oscillator, where the at least one output of the mixer circuitry is directly connected to an input of the terminal RF output circuitry. The circuit may further include terminal Intermediate Frequency (IF) output circuitry that is isolated from the local oscillator, where the at least one output of the mixer circuitry is directly connected to an input of the terminal IF output circuitry.
Abstract:
A biasing circuit for biasing an output transistor in a radio frequency (RF) amplifier includes a first field-effect transistor (FET) monolithically integrated with the output transistor, the first FET being connected to the output transistor in a current mirror configuration, such that a gate-to-source voltage of the first FET is the same as a gate-to-source voltage of the output transistor, and a drain current in the first FET is matched to a drain current in the output transistor and scaled proportionally according to a size of the first FET relative to a size of the output transistor. The biasing circuit further includes a voltage divider integrated with the first FET and connected to a current source, the voltage divider being configured to generate a voltage that is substantially independent of process, voltage and/or temperature variations for controlling the drain current in the first FET.
Abstract:
An angular deviation optical tracking and detector device for use in optical systems such as a FSO communication systems—among others. The angular deviation optical tracking and detector device includes position sensor elements that are configured to detect any misalignment of incoming/received light and an optical tunnel structure coupled with a detector array to determine the angular deviation. The optical tracking and detector device includes a position sensor having an optical aperture configured to allow a portion of incoming light to pass through the position sensor; a plurality of position receivers positioned adjacent to the optical aperture, the plurality of position receivers configured to sense portions of the incoming light; and an optical detector array configured to detect portions of the incoming light that passes through the position sensor aperture and optical tunnel. Angular deviation may be determined from diode array readout of illuminated individual diodes.
Abstract:
A semiconductor optical device includes a first facet bounding a first end of the semiconductor optical device. The semiconductor optical device further includes a waveguide having a first end proximate the first facet, the first end of the waveguide being tapered towards the first facet. The first facet has a curvature to increase modal reflectivity at a first interface at which the first end of the waveguide meets the first facet.
Abstract:
A number of different types of semiconductor material structures and wafers, including epiwafers, are described herein. The semiconductor material wafers are optimized in certain aspects to form transistor amplifiers for use with new modulation communications systems. A semiconductor material wafer includes a silicon carbide substrate and at least one III-nitride material layer over the silicon carbide substrate. The semiconductor material wafers can include layers consisting of semiconductor materials without dopants such as iron or carbon, formed over the silicon carbide substrate.
Abstract:
A communication interface comprising a host with non-linear equalizers configured to perform non-linear equalization. Also part of the interface is a host to optic module channel electrically connecting the host to an optic module and the optic module. The optic module comprises a transmitter and a receiver. The transmitter includes a linear equalizer and an electrical to optical module configured to convert the equalized signal from the driver to an optical signal, and transmit the optical signal over a fiber optic cable, such that the transmitter does not perform non-linear processing. The receiver includes a photodetector, configured to convert the received optic signal to a received electrical signal, and a linear amplifier configured to perform linear amplification on the received electrical signal. A driver sends the amplified received signal over an optic module to host channel, such that the receive does not perform non-linear processing.
Abstract:
Various aspects provide for error detection and compensation for a multiplexing transmitter. For example, a system can include an error detector circuit and a duty cycle correction circuit. The error detector circuit is configured to measure duty cycle error for a clock associated with a transmitter to generate error detector output based on a clock pattern for output generated by the transmitter in response to a defined bit pattern. The duty cycle correction circuit is configured to adjust the clock associated with the transmitter based on the error detector output. Additionally or alternatively, the error detector circuit is configured to measure quadrature error between an in-phase clock and a quadrature clock in response to the defined bit pattern. Additionally or alternatively, the system can include a quadrature error correction circuit configured to adjust phase shift between the in-phase clock and the quadrature clock based on quadrature error.
Abstract:
RF transistor amplifiers include a Group III nitride-based RF transistor amplifier die that includes a semiconductor layer structure, a conductive source via that is connected to a source region of the Group III nitride-based RF transistor amplifier die, the conductive source via extending through the semiconductor layer structure, and an additional conductive via that extends through the semiconductor layer structure. A first end of the additional conductive via is connected to a first external circuit and a second end of the additional conductive via that is opposite the first end is connected to a first matching circuit.