After the Korean WarSouth Korean military was an acquaintance with the modern at the time solid-American missiles: It has clean rooms of "class " equipped to build spacecraft components, shaker, measuring system of moment characteristics of vehicles weighing up to 3. In Korea established production of solid propellant rocket motors weighing up to a ton. These engines are used in modified Nike Hercules, which the South Korean military is used as missiles "surface - the surface" with a range of up to km.
Other demanding applications, including aircraft controls, automotive airbag modules, and advanced driver assist systems ADAS — many of which used to rely on human cognition and action — are now recognized as life-dependent electronics systems as well.
These systems rely on a vast array of ultra-high-reliability electronics to deliver reliable, life-preserving performance and have spurned the development of a new wave of advanced passive components capable of executing essential, enabling tasks within the various life-dependent end devices that now extend across several electronics markets.
This article will provide an update on two advanced capacitor technologies that provide the peak performance, high reliability, and environmental ruggedness required to enable the ever-expanding swath of life-dependent, harsh-environment automotive, aerospace, and defense electronics.
Flexible-termination MLCCs for harsh environments Automotive electronics systems are expanding at a staggering rate.
The influx of new specifications and designs has elicited the development of myriad enabling devices, including new families of electronic modules designed especially for use in applications with high temperatures, high vibration, and high thermal cycling.
The development of these modules demanded a termination system that could withstand physical flexure and strain resulting from coefficient of thermal expansion CTE mismatches between multilayer ceramic capacitors MLCCs and a PCB. This capability was achieved by adding a conductive epoxy layer under the final termination finish.
The material properties of this layer allow the terminations to withstand up to 5 mm of board flexure with no penalty in terms of increased ESR or ESR instability either over time or due to the effects of environmental conditions. Various component families now utilize this flexible termination technology, and they are widely employed in high-reliability applications in which the failure of a single capacitor could shut down the entire system.
Examples include low-leakage input capacitors in automotive modules and high-voltage or high-temperature capacitors in power drive snubbers or filters. Since their introduction, the cost of flexible-termination MLCCs has continued to drop relative to the costs of the end system, associated repairs, and replacements, and especially the downtime typically associated with a failed system.
Expanded application employment, especially within the automotive and avionics markets, elicited additional performance demands, including the elimination of the threat of cracked capacitor resulting from board flexure.
The electrodes in this design have a favorably decreased dimension relative to two standard MLCCs in series, which effectively minimizes ESR, and eliminate the board traces between two capacitors in a series, which significantly reduces ESL. Furthermore, by virtue of having two capacitors in series, these MLCCs deliver the extremely high reliability required for employment in the critical control signal lines of avionic electronics, as well as in the active safety and ADAS of automotive control modules.
ADAS systems, including automated lighting and braking, adaptive cruise control, smartphone connections, and lane and blind spot alerts, are now employed in a majority of new vehicles, and the critical control signal lines in these systems cannot withstand a capacitor failure without causing a complete system shutdown.
High-reliability base metal electrode MLCCs The new, broader pool of life-dependent electronics applications also includes avionics and military defense, communications, and weapons systems.
These systems require small, lightweight components with space-level reliability and cost-effective pricing, which is a fairly tall order. Base metal electrode BME MLCCs, which have long delivered higher capacitance values and a wider voltage range in packages up to four times smaller than equivalent precious metal electrode PME MLCCs in commercial and automotive applications, are one effective solution capable of satisfying these demands.
In recent years, BME MLCCs incorporated significant design and manufacturing improvements that further enhanced their performance to the point of proven PME reliability equivalence while maintaining their comparatively small size, light weight, and low cost.
As such, these MLCCs are now approved for use in space-level and other life-dependent, harsh-environment applications. Design and process improvements responsible for catapulting BME MLCC technology to reliability levels required for life-dependent applications include: The individual dielectric layers, capacitor cover layers, margin areas, and FLEXITERM layer provide these parts with enhanced protection from overvoltage stress and external environment influences.
With case sizes spanning tocapacitance values ranging from 2. As electronics continue to permeate nearly each and every aspect of our lives, the list of applications recognized as life-dependent will continue to expand beyond the implantable medical electronics that initially comprised this category, as well as the avionics, aerospace, and ADAS applications that have already extended the parameters of category and challenged engineers to develop new component solutions capable of consistently delivering high-reliability, long-lifetime performance in smaller, lighter-weight form factors with cost-effective pricing.
The development and market introduction of MLCCs with flexible terminations and attractive performance characteristics and BME MLCCs with PME-equivalent, space-level reliability, smaller, lighter-weight form factors, extended capacitance and voltage capabilities, and lower costs have satisfied current component challenges resulting from this expanding electronics category, but manufacturers must continuously work to develop new, improved, and innovative passive components capable of satisfying next-generation design requirements at the board level.
The rate of electronic evolution is only speeding up, if anything, and suppliers will always be challenged to deliver better performance in less space at lower costs.CHAPTER 1 — BASIC RADAR PRINCIPLES AND GENERAL CHARACTERISTICS INTRODUCTION The word radar is an acronym derived from the phrase RAdio Detection And Ranging and applies to electronic equipment designed for detecting and tracking objects (targets) at .
Early radar equipment was adapted from the radio communications field, using HF, VHF, and UHF tubes and antenna techniques. The British, faced with the most urgent need to deploy equipment, designed the Chain Home system to work at 25 MHz. The Space and Missile Systems Center (SMC), Military Satellite Communications Systems (MILSATCOM) Directorate (MC), Los Angeles Air Force Base, California hereby issues the following Request for Information (RFI).
The Synthetic Aperture Radar has a long history in developing technologies and components since borne systems which are operational till today. Environmental monitoring, earth-resource mapping, and military systems require broad-area imaging at high resolutions.
right of the sub satellite track. The radar swath itself is divided in a.
In communication with the publisher of this web site, Ted Molczan, a prominent satellite observer, reported that Kosmos was circling the Earth in a by kilometer orbit, which would be too low for most electronic intelligence purposes and too elliptical for practical radar observations.
History of Satellite Communications Joseph N. Pelton Contents A brief history of military satellite systems and the “dual use” of commercial satellite systems to Introduction The idea of satellite communications is a powerful one that has spawned a billion.