Semiconductors & ICs

Semiconductor Laser Technology Chosen for Space LIDAR

Single-frequency semiconductor laserRedfern Integrated Optics (RIO)Santa Clara,

NASA has chosen Redfern Integrated Optics to further develop a single-frequency, narrow-linewidth semiconductor laser suitable for spaceflight operation. RIO’s external-cavity semiconductor laser technology is based on the hybrid integration of an indium phosphide (InP) gain chip and a planar lightwave circuit (PLC) with Bragg gratings. Packaged in a standard 14-pin compact “butterfly” package, the laser is characterized by a single-frequency output in the 1550-nm spectral region with a linewidth less than 2 kHz, low phase noise, low relative intensity noise (RIN), and high immunity to vibrations in a wide range of operating temperatures.

Posted in: Application Briefs, Lasers & Laser Systems, Semiconductors & ICs, Lidar, Suppliers, Semiconductors

Interface Supports Multiple Broadcast Transceivers for Flight Applications

A wireless avionics interface provides a mechanism for managing multiple broadcast transceivers. This interface isolates the control logic required to support multiple transceivers so that the flight application does not have to manage wireless transceivers. All of the logic to select transceivers, detect transmitter and receiver faults, and take autonomous recovery action is contained in the interface, which is not restricted to using wireless transceivers. Wired, wireless, and mixed transceiver technologies are supported.

Posted in: Briefs, Semiconductors & ICs, Avionics, Data exchange, Integrated circuits, Wireless communication systems

FPGA Sequencer for Radar Altimeter Applications

A sequencer for a radar altimeter provides accurate attitude information for a reliable soft landing of the Mars Science Laboratory (MSL). This is a field-programmable-gate-array (FPGA)-only implementation. A table loaded externally into the FPGA controls timing, processing, and decision structures. Radar is memory-less and does not use previous acquisitions to assist in the current acquisition. All cycles complete in exactly 50 milliseconds, regardless of range or whether a target was found.

Posted in: Briefs, Semiconductors & ICs, Altimeters, Attitude control, Integrated circuits, Radar, Spacecraft guidance, Entry, descent, and landing

SAD5 Stereo Correlation Line-Striping in an FPGA

High precision SAD5 stereo computations can be performed in an FPGA (field-programmable gate array) at much higher speeds than possible in a conventional CPU (central processing unit), but this uses large amounts of FPGA resources that scale with image size. Of the two key resources in an FPGA, Slices and BRAM (block RAM), Slices scale linearly in the new algorithm with image size, and BRAM scales quadratically with image size. An approach was developed to trade latency for BRAM by sub-windowing the image vertically into overlapping strips and stitching the outputs together to create a single continuous disparity output.

Posted in: Briefs, TSP, Semiconductors & ICs, Mathematical models, Antennas, Architecture, Integrated circuits

Miniature Sapphire Acoustic Resonator — MSAR

Q values as high as 108 may be achieved at room temperature.

A room temperature sapphire acoustics resonator incorporated into an oscillator represents a possible opportunity to improve on quartz ultrastable oscillator (USO) performance, which has been a staple for NASA missions since the inception of spaceflight. Where quartz technology is very mature and shows a performance improvement of perhaps 1 dB/decade, these sapphire acoustic resonators when integrated with matured quartz electronics could achieve a frequency stability improvement of 10 dB or more. As quartz oscillators are an essential element of nearly all types of frequency standards and reference systems, the success of MSAR would advance the development of frequency standards and systems for both ground-based and flight-based projects.

Posted in: Briefs, Semiconductors & ICs, Product development, Standardization, Semiconductors, Acoustics

Process-Hardened, Multi-Analyte Sensor for Characterizing Rocket Plume Constituents

A multi-analyte sensor was developed that enables simultaneous detection of rocket engine combustion-product molecules in a launch-vehicle ground test stand. The sensor was developed using a pin-printing method by incorporating multiple sensor elements on a single chip. It demonstrated accurate and sensitive detection of analytes such as carbon dioxide, carbon monoxide, kerosene, isopropanol, and ethylene from a single measurement.

Posted in: Briefs, Semiconductors & ICs, Integrated circuits, Sensors and actuators, Emissions measurement, Semiconductors, Rocket engines

Making Multicore Work With Minimal Pain Points

All major microprocessor vendors are introducing multicore architectures to deliver the latest installment of performance improvements and cost savings as required to remain competitive in the silicon marketplace. Indeed, multicore processors offer increases in processing throughput, savings in power consumption, and reductions in heat dissipation. However, some effort is required to fully exploit multicore benefits. Unfortunately, the transition to a multicore architecture is often best described by the old adage, “no pain, no gain.”

Posted in: Articles, Semiconductors & ICs, Architecture, Computer software and hardware

Compact, Reliable EEPROM Controller

This controller prevents inadvertent writes in an EEPROM.

A compact, reliable controller for an electrically erasable, programmable readonly memory (EEPROM) has been developed specifically for a space-flight application. The design may be adaptable to other applications in which there are requirements for reliability in general and, in particular, for prevention of inadvertent writing of data in EEPROM cells.

Posted in: Briefs, Semiconductors & ICs, Computer software and hardware, Electronic control units, Semiconductors, Reliability, Spacecraft

Ka-Band Waveguide Two-Way Hybrid Combiner for MMIC Amplifiers

This technology is applicable as a power combiner for solid-state power amplifiers (SSPAs) with unequal and arbitrary power output ratios.

The design, simulation, and characterization of a novel Ka-band (32.05±0.25 GHz) rectangular waveguide two-way branch-line hybrid unequal power combiner (with port impedances matched to that of a standard WR-28 waveguide) has been created to combine input signals, which are in phase and with an amplitude ratio of two. The measured return loss and isolation of the branch-line hybrid are better than 22 and 27 dB, respectively. The measured combining efficiency is 92.9 percent at the center frequency of 32.05 GHz. This circuit is efficacious in combining the unequal output power from two Ka-band GaAs pseudomorphic high electron mobility transistor (pHEMT) monolithic microwave integrated circuit (MMIC) power amplifiers (PAs) with high efficiency.

Posted in: Briefs, TSP, Semiconductors & ICs, Amplifiers, Integrated circuits, Waveguides

Quad-Chip Double-Balanced Frequency Tripler

This technology has uses such as high-resolution radar and spectroscopic screening.

Solid-state frequency multipliers are used to produce tunable broadband sources at millimeter and submillimeter wavelengths. The maximum power produced by a single chip is limited by the electrical breakdown of the semiconductor and by the thermal management properties of the chip. The solution is to split the drive power to a frequency tripler using waveguides to divide the power among four chips, then recombine the output power from the four chips back into a single waveguide.

Posted in: Briefs, TSP, Semiconductors & ICs, Integrated circuits, Waveguides, Semiconductors

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