New Energy Source Powers Single-Use Mil/Aero Equipment

Until recently, single-use high energy devices were typically powered by reserve/thermal batteries using decades-old technology. Recognizing that battery performance limitations could hinder new product development, the U.S. DoD identified a “critical need” for a new generation of high-power, long life batteries.

Posted in: Application Briefs, Defense, Batteries, Research and development, Reliability

Spectrally Compliant Waveforms for Wideband Radar

Modern radars often require the use of wideband waveforms to perform high-resolution target imaging. In microwave systems, the bandwidth can be on the order of 1.5 GHz, while in UHF systems that typically operate between 200 and 500 MHz, the waveform bandwidth might exceed 200 MHz. A major issue in the operation of such systems is that they often overlap the spectrum used by other radars, and even the spectrum allocated for other types of systems such as communications and navigation devices.

Posted in: Application Briefs, Radar, Waveguides, Noise

Five Approaches to Cooling Military Electronics

Seventy-one degrees C is the temperature of a steak done medium-well. It is also the temperature of an oven used to test thermal characteristics of military electronics. Electronic components in the COTS industry often have temperature limits of 85°C, leaving 14°C of thermal potential to move the heat generated by the components away. Among various cooling approaches, the correct solution for your application depends on meeting your requirements at the lowest possible cost and complexity.

Posted in: Articles, Aerospace, Electronic equipment, Test equipment and instrumentation, Thermal testing, Military vehicles and equipment

Prototyping with Multi-Layer Boards

As electronic components continue to move increasingly into surface- mount packages exclusively, prototype manufacturing firms are seeing a shift in the fabrication and assembly work needed to implement engineering prototypes. The shift is subtle but relentless; as new components come to market in SMT packages, QFPs, BGAs and the like, board design and assembly for prototypes must change to accommodate the surface mount components.

Posted in: Articles, Aerospace, Rapid prototyping, Electronic equipment, Assembling, Fabrication

Gas Turbine Exhaust Recovery Design Improves Propulsion Efficiency

In January, Concepts NREC (CN) was awarded a Phase I Small Business Innovative Research (SBIR) grant from the Navy to improve the power efficiency of its gas turbine prime movers used for ship propulsion. The eight-month analytical study is in collaboration with the Maine Maritime Academy and its principal consultant, Travis Wallace, President, Thermoelectric Power Systems, LLC. The Navy’s RFP required that the power recovery system improve the power output of the prime mover by at least 20%. However, considerations included the effects that transient power demand from the prime mover has on the waste heat flow rate and temperature, which may consequently affect the fatigue integrity of the heat exchangers and stability of the turbomachinery subsystems.

Posted in: Application Briefs, Waste heat utilization, Thermodynamics, Gas turbines, Marine vehicles and equipment

Realistic Simulation Makes Army Helmets Safer

As materials, ergonomic design, and ballistics protection have evolved, the U.S. Army helmet has improved in form and function, from the M1 of WWII, to the 29-layer Kevlar PASGT (Personnel Armor System for Ground Troops), to finally the lighter Kevlar/Twaron ACH (Advanced Combat Helmet) design of today (Figure 1). Helmet liners have progressed too, from compressed paper fibers, plastic, and rayon in the early days to more sophisticated suspension-webbing systems with chin straps constructed from stronger synthetics.

Posted in: Application Briefs, Computer simulation, Finite element analysis, Defense industry, Materials properties, Helmets

Impact of Materials on Microwave Cable Performance

The environments in which microwave cable assemblies are being used today are becoming more challenging with exposure to such conditions as extreme temperatures, chemicals, abrasion, and flexing. Additional challenges include the need for smaller, lighter packaging for cable systems that last longer and cost less. To ensure signal integrity and product reliability, it is essential to identify the electrical, mechanical, environmental, and application-specific constraints that can affect the cable’s overall performance.

Posted in: Application Briefs, RFM Catchall, Electric cables, Materials properties, Polymers