Electrical/​Electronics

Berkeley Laboratory researchers have demonstrated a novel superconducting gradiometer that helps to reduce ambient magnetic field noise generated by relatively distant sources in favor of tiny magnetic signals generated by a local source. This is another step toward the operation of SQUID-based instruments...

Research closely related to that reported in the preceding article has shown that δ-doped charge-coupled devices (CCDs) could be used to detect incident protons and perhaps other positive ions, and to measure the kinetic energies of the ions, down to about 1.25 keV. Prior to the development...

A technique for estimating the boresight direction of a Global Positioning System (GPS) receiver antenna involves utilization of the relationship between the strengths of received signals and the direction-dependent antenna gain pattern. The technique is fundamentally different from, and...

A report discusses the performance of a soft digital-data-transition tracking loop (DTTL) in a radio receiver that recovers digital data conveyed by binary phase-shift keying. The DTTL is used as a symbol synchronizer; it provides symbol timing to essential parts of the receiver. The DTTL...

An automated system of computer hardware and software has been developed for managing construction projects at Stennis Space Center. This system replaces an older collection of paper-based subsystems, wherein documents were copied, filed, and distributed in labor-intensive processes. Data...

An integrated circuit (IC) physical layout has been developed for the HCD ASIC - an application-specific integrated circuit that decodes digital command signals transmitted from a ground station to a spacecraft (uplink commands). The HCD ASIC is described in "Hardware-Command-Decoding ASIC" (NPO-19615), which...

Two short reports describe a micromachined quantum-mechanical-tunneling accelerometer and radiation-hardened support electronics designed for use in outer space. Like the micromachined tunneling accelerometers described previously in NASA Tech Briefs, this device is based on the use of...

A document presents a comprehensive overview of the technology of tapered-slot antennas and arrays of such antennas. The fundamental operation of tapered-slot antennas is not yet fully understood, and, for lack of established design rules, the designs of these antennas have been based primarily on empirical...

An excerpt from JPL Document D-12104 presents additional information on the control system of a steerable microwave antenna that is mounted on the roof of a land vehicle and used to communicate with a geostationary satellite. The antenna and control system were described previously in...

When a silicon wafer is cut from an ingot, it is essentially impossible to align the cut perfectly with the crystal structure. Therefore the surface contour of the wafer will be a flat plane on which terraces consisting of additional atomic layers will be scattered. An atomic step will be...