SLIDES Besser 1sep15

www.BesserAssociates.com

Components for Aerospace

and Defense Presented by

Dr. Bob Froelich of

Besser Associates, Inc.


Sponsored by: National Instruments (formerly AWR Corp.)

online at www.ni.com/awr

ni.com/awr

AWR Is Now NI

NI AWR Design Environment

Product Line Overview Presentation

3 ni.com ni.com/awr

NI AWR Design Environment - At a Glance

Software Product Portfolio

Microwave Office - MMIC, RF PCB and module circuit design

Visual System Simulator - Wireless communications/radar systems design

AXIEM - 3D planar electromagnetic (EM) analysis

Analyst - 3D finite element method (FEM) EM analysis

Analog Office - Analog/RFIC circuit design

Global Presence (sales & support office locations)

California, Wisconsin, Colorado

United Kingdom, Finland, France and Germany

Japan, Korea, Taiwan, China and Australia

4 ni.com ni.com/awr

Microwave Office -

RF and Microwave Design

Application Areas:

MMICs (III-V compound semiconductors)

RF PCBs and modules

Product Strengths:

Electrical/physical concurrent design

RF-aware layout

Tuning, optimization, yield analysis

Circuit design thru to EM analysis

5 ni.com ni.com/awr

Learn More

Online

ni.com/awr

awr.tv

Email

[email protected]


Components for Aerospace

and Defense

Presented by

Dr. Bob Froelich of

Besser Associates, Inc.



Outline

Market Comparison

Standards

Material and Process Limitations in Defense

Microwave Applications in Defense


Defense and Space vs Commercial

The Commercial environment: Anything goes within legal limits on safety, use of IP, etc. The market place picks the winning product.

Defense: A raft of preconditions Reliability and lifetime in harsh environments Maintainability and compatibility with other equipment Training requirements Use of strategic materials Business is won in advance of full production.

Space: Reliability is paramount Material and process characteristics strictly enforced. High MTBF and avoidance of stress limits. Business is won by prototypes and proposals.

Most real world situations fall on a continuum among these.


Standards

In an enormous number of areas, its better not to reinvent the wheel with every new design. Examples are

Compositions of materials, e.g. metal alloys Part sizes for screws, drills, wire, etc. Documentation practices Human safety Definitions of operating and storage environments (temperature, humidity, etc.) Purchasing and manufacturing processes Units and measurements (Ohms, Volts, cm, return loss, degrees, gallons,

hardness, transparency, smoothness, r, , etc, etc)

Reference to predetermined standards saves tremendous time and labor. There are thousands of documents describing standards of all kinds. Organizations that issue and maintain standards documents include

Government Military Space agencies Industry groups (EIA, ISO, IPC, JEDEC) Professional organizations (ASME, ASTM, IEEE, ASCE)


Types of US Defense Standards

MIL-HBK: Handbook containing guidance and information on materials, design and processes in a given area.

MIL-SPEC: Specification of technical requirements for purchased material or products.

MIL-STD: Standard for processes and procedures.

MIL-PRF: Performance specification that states required results without dictating the methods to achieve them.

MIL-DTL: Detail specification on how a requirement is to be achieved.

Copies of many standards are available from http://www.everyspec.com


Some Standards that Apply to

Microwave Electronics for Defense

IPC/EIA J-STD-001: Standard requirements for soldering.

MIL-PRF-19500 : General specification for semiconductor devices.

MIL-PRF-38534: General specification for hybrid microcircuits.

MIL-STD-461: Control of EMI characteristics. MIL-STD-810: Environmental test methods. MIL-STD-883: Microelectronics test methods. MIL-HDBK-217: Reliability prediction of electronic

equipment.

MIL-HBK-454: Standard requirements for electronic equipment.


Tin and Lead

In 2003 the EU adopted the Restriction of Hazardous Substances Directive (RoHS) Most notably, it forbids the use of lead. Most of the commercial electronics industry has converted to

Lead-free solders and lead-free plating on package leads. Often the plating is pure tin.

Problem: Tin-plated surfaces often grow whiskers, i.e. small metal wires, that result in short circuits or arcing. See picture gallery at

http://nepp.nasa.gov/WHISKER/photos/index.html

Most military and space programs forbid the use of pure tin plating. MIL-PRF1900 calls for 3% lead by mass, minimum, in tin-based plating.

This can greatly complicate procurement of parts!


Plastic and Hermetic Packages

Plastic packages

Industry standard for most ICs

Not hermetic (work with LCP has been promising)

Reliability problems:

Moisture promotes chemical reactions.

Frost can do physical damage below freezing.

Steam can explode a package during solder reflow.

Hermetic packages

Ceramic or metal with chip and wire assembly inside.

Usually much more expensive.

Compromise: Conformal coating of PCBA


Military Applications of Microwaves

Communication Data or voice

Real time or not real time

Long- or short-distance, covert or open

Radar Ground based, ship based, air based

Target ID, tracking, proximity, avoidance, mapping

ECM Signal intercept and identification

Disruption

Applications range from very specific and narrow bandwidth to very general and very wide bandwidth.


RADAR

Objects detected by reflecting EM energy back to the source.

Easy for the target to detect!

General requirements High power

Highly directional antenna

Sensitive receiver with high dynamic range

Microwave bandwidth usually narrow or moderate.

Signal processing to extract info on range, velocity, identity, etc.


Radar Components

Antennas Mechanically Scanned Phased array (electronically scanned)

Example: AEGIS system

Multiple pattern Example: Airborne slot array

http://www.rantecantennas.com/antennas

Transmitters Pulsed (fixed frequency or modulated) Continuous (CW or FM) Very high power (~106 W) in some systems.

Receivers High sensitivity High dynamic range Survival at high input power levels


Radar System Example

Transmitter

Sum

Receiver

Elevation

Receiver

Azimuth

Receiver

High Power

Circulator

Limiter

Limiter

Limiter

Array

Antenna


ECM Receivers

Detect and identify incident energy.

Very low emissions to stay hidden.

Wide microwave tuning range, e.g. 0.5 to 18 GHz.

Wide instantaneous bandwidth, e.g. 1GHz

High dynamic range so that

Weak signals are not drowned out by noise and interference.

Strong signals do not generate false responses.


Receiver Components

Filters Pre-selector filters reject interfering signals. Channel filter sets instantaneous bandwidth. Group delay, bandwidth and out-of-band rejection can all be important.

Amplifiers Various combinations of low noise figure, high bandwidth, and high

linearity.

Mixers High linearity High isolation

Local oscillator/synthesizer Fast tuning Accuracy Low phase noise


ECM Receiver Example

Multi -

Throw

Switch

Pre-selector, band 1

Pre-selector, band N

Multi -

Throw

Switch

..

...

Channel

Filter

LO

Synthesizer

Ant

Broad Band

LNA

Single-Band

LNAs

IF Amplifier


Thank you for Attending ! For more information on this subject and more,

please consider enrolling in:

RF Design: Applied Techniques

September 14 to 18, 2015, San Jose, CA

Contact us at [email protected] for details.

Please visit www.BesserAssociates.com for a complete course listing.

Sponsored by: National Instruments (formerly AWR Corp.)

online at www.ni.com/awr

Date post:	07-Jan-2016
Category:	Documents
Upload:	teddy112
View:	227 times
Download:	0 times

SLIDES Besser 1sep15

Documents