Keyword: Chokes

Articles: Motion Control

Electromagnetic compatibility (EMC) in frequency converters can be very problematic if not addressed properly in the initial design. EMC ensures the proper operation of devices to avoid negative...

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Briefs: Photonics/Optics

Photonic choke-joint (PCJ) structures for dual-polarization waveguides have been investigated at NASA's Goddard Space Flight Center for use in device and component packaging. This...

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Briefs: Photonics/Optics
Compact Planar Microwave Blocking Filters

Innovators at NASA's Goddard Space Flight Center have designed, fabricated, and characterized absorptive thermal blocking filters for cryogenic microwave applications. The device allows direct integration of the high-frequency signal and microwave readout, and mitigates spurious resonances in the circuit...

Briefs: Manufacturing & Prototyping
Fabrication of an Integrated Photonic Waveguide Joint in Micromachined Silicon

High-aspect-ratio silicon structures are necessary components in many MEMS (microelectromechanical systems). Aspect ratio is defined as the ratio of the height of the structure to its lateral width. The structures are typically fabricated through bulk micromachining...

Briefs: Mechanical & Fluid Systems

Multipath, multistage, erosion-resistant flow control valves have been developed that can sustain the extremely high pressure of deep oil wells. Fitting in the...

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Briefs: Mechanical & Fluid Systems

Various applications exist where high-pressure valves are required, but the problem for control of such valves lies in that they have to move against a strong...

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Articles: Robotics, Automation & Control

Contemporary industrial automation control systems are employing variable frequency drives (VFDs) in ever-increasing numbers. VFDs give control engineers...

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Briefs: Robotics, Automation & Control
Electric Machine With Boosted Inductance to Stabilize Current Control

High-powered motors typically have very low resistance and inductance (R and L) in their windings. This makes the pulse-width modulated (PWM) control of the current very difficult, especially when the bus voltage (V) is high. These R and L values are dictated by the motor...

Briefs: Manufacturing & Prototyping
Process for Patterning Indium for Bump Bonding

An innovation was created for the Cosmology Large Angular Scale Surveyor for integration of low-temperature detector chips with a silicon backshort and a silicon photonic choke through flip-chip bonding. Indium bumps are typically patterned using liftoff processes, which require thick resist. In...

Briefs: Manufacturing & Prototyping

Plasma pyrolysis of methane has been investigated for utility as a process for producing hydrogen. This process was conceived as a means of recovering hydrogen from methane produced as a...

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Briefs: Semiconductors & ICs

A multichannel dielectric-resonator oscillator (DRO), built as a prototype of a local oscillator for an X-band transmitter or receiver, is capable of being electrically tuned among and...

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Briefs: Semiconductors & ICs

A waveguide power-amplifier module capable of operating over the frequency range from 80 to 150 GHz has been constructed. The module comprises a previously reported power amplifier packaged...

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Briefs: Software
Routines for Computing Pressure Drops in Venturis

A set of computer- program routines has been developed for calculating pressure drops and recoveries of flows through standard venturis, nozzle venturis, and orifices. Relative to prior methods used for such calculations, the method implemented by these routines offers greater accuracy because it...