Abstract: Driving circuitry is described that includes multiple programmable bias voltages useful for biasing radio-frequency components such as PIN diodes and gallium-nitride devices. Programmable voltages as high as 30 volts and as low as ?20 volts are generated. The drive circuitry can operate from a single, low-voltage power source.

Abstract: Radio-frequency signals may be switched between signal lines or signal ports in RF circuits using PIN diodes and PIN-diode driving circuitry. To achieve switching, the PIN diodes are biased at voltages as high as 20 volts or more. Circuitry for biasing PIN diodes is described that uses a low-voltage power source and a single-bit control line.

Abstract: A multi-voltage converter is described that includes multiple programmable bias voltages of positive and negative values that may be used to bias radio-frequency components such as PIN diodes and gallium-nitride devices. Programmable voltages as high as 30 volts and as low as ?20 volts are generated. Outputs may be provided to a sequencing circuit for biasing gallium-nitride transistors and amplifiers.

Abstract: Circuits and operating methods thereof for correcting phase errors introduced by amplifiers employing gallium nitride (GaN) transistors are described. The phase errors are caused by trapping effects exhibited by the GaN transistors. The circuits described herein pre-distort the phase of the input signal to compensate for the phase error introduced by the amplifier. Thereby, the phase of the output signal of the amplifier has a reduced phase error. For example, the output signal may have a near zero (or zero) phase error.

Abstract: The automatic adjustment of output power of a transmitter is described. In one embodiment, an optical transmitter is directed to transmit a pulse of light over a communications link, such as a fiber optic cable, and a timer is started with reference to the transmission. An output tap of the transmitter is monitored to detect the transmission of the pulse of light and any reflection events which occur due to the transmission. A final reflection event is identified, along with a timing associated with the final reflection event using the timer. A length of the communications link is estimated based on the timing. An updated output power for the transmitter is calculated based on the estimated length of the communications link. The output power for the transmitter can be reduced when the length of the link is less than that expected, while maintaining a minimum power margin at a receiver.

Abstract: III-nitride materials are generally described herein, including material structures comprising III-nitride material regions and silicon-containing substrates. Certain embodiments are related to gallium nitride materials and material structures comprising gallium nitride material regions and silicon-containing substrates.

Abstract: III-nitride materials are generally described herein, including material structures comprising III-nitride material regions and silicon-containing substrates. Certain embodiments are related to gallium nitride materials and material structures comprising gallium nitride material regions and silicon-containing substrates.

Abstract: Package assemblies for improving heat dissipation of high-power components in microwave circuits are described. A laminate that includes microwave circuitry may have cut-outs that allow high-power components to be mounted directly on a heat slug below the laminate. Electrical connections to circuitry on the laminate may be made with wire bonds. The packaging allows more flexible design and tuning of packaged microwave circuitry.

Abstract: An oscillator apparatus includes: a voltage controlled oscillator that generates an oscillator output including a fundamental frequency, wherein the fundamental frequency is a function of a tuning voltage; and a tunable filter that receives the oscillator output and provides a filtered oscillator output, wherein the tunable filter has a frequency characteristic that suppresses a harmonic of the fundamental frequency, the frequency characteristic being a function of the tuning voltage.

Abstract: A laser chip having a substrate, an epitaxial structure on the substrate, the epitaxial structure including an active region and the active region generating light, a waveguide formed in the epitaxial structure extending in a first direction, the waveguide having a front etched facet and a back etched facet that define an edge-emitting laser, and a first recessed region formed in the epitaxial structure, the first recessed region being arranged at a distance from the waveguide and having an opening adjacent to the back etched facet, the first recessed region facilitating testing of an adjacent laser chip prior to singulation of the laser chip.

Abstract: Circuits for protecting devices, such as gallium nitride (GaN) devices, and operating methods thereof are described. Such circuits may include a temperature sensor configured to sense the temperature of at least a portion of a device, and a phase shifter configured to shift the phase of the signal output by the device, when the sensed temperature is outside a safe temperature range, e.g., above a predefined temperature threshold. The phase may be shifted discretely or continuously. These circuits safeguard devices from damaging operating conditions to prolong the operating life of the protected devices.

Abstract: An apparatus includes a first circuit, a second circuit and a third circuit. The first circuit may be configured to generate a plurality of second signals by a voltage translation of a plurality of first signals. The second circuit may be configured to switch the second signals to generate a plurality of third signals. The second signals are generally switched such that (i) all third signals are inactive before one of the third signals transitions from inactive to active while a switching condition is enabled and (ii) all third signals are switched inactive while the switching condition is disabled. The third circuit may be configured to amplify the third signals to generate a plurality of output signals. Each of the output signals generally has a current capacity to drive one or more of a plurality of diodes in a diode switch circuit.

Abstract: A laser chip having a substrate, an epitaxial structure on the substrate, the epitaxial structure including an active region and the active region generating light, a waveguide formed in the epitaxial structure extending in a first direction, the waveguide having a front etched facet and a back etched facet that define an edge-emitting laser, and a first recessed region formed in the epitaxial structure, the first recessed region being arranged at a distance from the waveguide and having an opening adjacent to the back etched facet, the first recessed region facilitating testing of an adjacent laser chip prior to singulation of the laser chip.

Abstract: Methods and structures for improving the performance of integrated semiconductor transistors operating at high frequency and/or high power are described. Two capacitors may be connected to an input of a semiconductor transistor and tuned to suppress second-harmonic generation and to transform and match the input impedance of the device. A two-stage tuning procedure is described. The transistor may comprise gallium nitride and may be configured as a power transistor capable of handling up to 1000 W of power. A tuned transistor may operate at frequencies up to 6 GHz with a peak drain efficiency greater than 60%.

Abstract: A switching circuit includes a first diode coupled between a first terminal and a second terminal, a second diode coupled between the first terminal and a third terminal, and a bias circuit coupled to the first terminal and configured to bias the first diode on and the second diode off in a first switch state and to bias the first diode off and the second diode on in a second switch state, the bias circuit including a voltage converter configured to convert a fixed voltage to an intermediate voltage and a current source coupled in series with the voltage converter.

Abstract: A transistor circuit includes a transistor having a gate terminal and first and second conduction terminals, a first circuit configured to convert an AC input signal of the transistor circuit to a gate bias voltage and to apply the gate bias voltage to the gate terminal of the transistor, a second circuit configured to convert the AC input signal of the transistor circuit to a control voltage, and a switching circuit configured to apply a first voltage to the first conduction terminal of the transistor in response to the control voltage.

Abstract: High power transistors, such as high power gallium nitride (GaN) transistors, are described. These high power transistors have larger total gate widths than conventional high power transistors by arranging multiple linear arrays of gate, drain, and source contacts in parallel. Thereby, the total gate width and the power rating of the high power transistor may be increased without elongating the die of the high power transistor. Accordingly, the die of the high power transistor may be mounted in a smaller circuit package relative to conventional dies with the same power rating.

Abstract: A laser chip having a substrate, an epitaxial structure on the substrate, the epitaxial structure including an active region and the active region generating light, a waveguide formed in the epitaxial structure extending in a first direction, the waveguide having a front etched facet and a back etched facet that define an edge-emitting laser, and a first recessed region formed in the epitaxial structure, the first recessed region being arranged at a distance from the waveguide and having an opening adjacent to the back etched facet, the first recessed region facilitating testing of an adjacent laser chip prior to singulation of the laser chip.

Abstract: III-nitride materials are generally described herein, including material structures comprising III-nitride material regions and silicon-containing substrates. Certain embodiments are related to gallium nitride materials and material structures comprising gallium nitride material regions and silicon-containing substrates.

Abstract: An apparatus includes a channel layer, a first layer, a hole barrier layer and a second layer. The channel layer may be configured to carry a drain current in response to a voltage at a gate node. The first layer may be between the channel layer and the gate node. The first layer generally has a first bandgap. The hole barrier layer may be in contact with the first layer. The hole barrier layer generally has a second bandgap that (i) forms a valence band offset relative to the first bandgap and (ii) is configured to impede holes generated in one or more of the channel layer and the first layer from reaching the gate node. The gate node may be in contact with the second layer. The apparatus generally forms a field effect transistor.