SYSTEM CONCEPTS

AbstractsMERS 1977(Mechanical Engineeringin Radar Symposium)

The MERS '77 RECORD has been issued as a publicatin of record

by the IEEE Aerospace and Electronic Systems Society. Abstracts

of the papers contained in the Record are published here for your

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Reference Publication 77CH1250-0 AES.

MERS '77 was held in Washington, D.C., on November 8-10,

1977.

Mechanical Design and Performance Studies for The GWS.25 Sur-veillance and Tracker System, A.T. Humphrey, G.E.C. -The GWS.25radar system currently in the final stages of environmental and seagoing trials provides an effective addition to the weapon systemused by the British Navy. The development programme necessaryto produce the hardware demanded considerable technological re-source and the paper attempts to highlight some of the features ofthe design and en-vironmental test programme and the problems metduring the various design stages. Constraints imposed by spatial,mass and mechanistic requirements necessitate the development ofnovel structural configurations. Thus the utilisation of finite ele-ment programs provide the only meaningful basis for mechanicalperformance studies. It is inevitable that hardware testing will high-light areas where improvements in the design need to be effected.Governmental and Company test facilities provide the medium forassessing the acceptability of the final design configuration.

Deployment Flexible Mechanical Design for a Mobile-3D RadarAntenna, M. Sugie, M. Kawai, M. Wakabayashi & Y Katou, NipponElectric Co., Ltd, -In designing a novel phase-frequency scannedphased array antenna, a planar array, constructed in two parts foropening and folding was developed. This was a means of providingthis antenna with flexible mobility by helicopter, truck etc. Alsodeployability within an hour without using loading equipment atany site was assured. Moreover, a shock-absorber was developed toreduce the weight of the planar array while making it shock-resis-tant. Details of the mechanical design during these developmentsare described, as well as details in finalizing the design on the basisof data obtained from strength and deployment tests performed ona mock-up planar array.

The Control of Tolerances in An Array Antenna, W.R. Fanning,G.N. Tsandoulas & M.A. Nader, M.L T. -An L-band, airborne phasedarray antenna has been designed, built, tested and flown through aseries of airborne experiments. The array works in the DisplacedPhase Center Antenna (DPCA) mode in which two beams, eachoriginating from different but overlapping parts of the aperture, areproduced and radiated sequentiaUy. The array provides high sub-clutter visibility of moving targets.

The design was driven by tight mechanical tolerances and a highdegree of component similarity as required to achieve excellentidentity between the phase and amplitude patterns of the two beams.Considerable design attention was needed in the areas of airframeanalysis and control of its termal distortion during flight, design ofthe antenna structure and antenna-aircraft interface and tolerancecontrol during fabrication of the array modules. In addition, thedevelopment of repeatable measurement techniques that limited thephase and amplitude measurement errors to about 0.10 and 0.01 dB,respectively, was accomplished.

The Viking Radar Systems-Design for Space Programs, H.G. Frank-land & N.J. Sawyer, Teledyne Ryan Electronics-This paper dis-cusses the general principles involved in preparing the mechanicaldesigns of sophisticated electronic systems for space use and howby careful consideration of all design, test and mission parameters,successful missions can be accomplished.

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By creating useful design, standardsBy care in selecting the correct materialsBy standardization of hardwareBy specific design for haat sterilizationBy simplicity of design.

Ku Band Integrated Radar/Commusications Subsystem for TheShuttle, L.C. Parode, Hughes-The Ku Band Subsystem for theSpace Shuttle Orbiter must operate as rendezvous radar and pro-vide two way communications with the ground. A discussion ofaccomplishing these objectives while meeting the additional

IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS VOL. AES-14, NO. 1 JANUARY 1978220

requirements of minimum weight, limited stowage volume, andadequate cooling is presented.

Implementation of Wind Performance Studies for Large AntennaStructures, R. Levy & M.S. Katow, JPL-Structural design pro-cedures are described for a large antenna system to meet perform-ance requirements under gravity and wind loading. A computa-tional method is shown for the evaluation of performance in re-sponse to wind loading. Cumulative probability distribution curvesfor wind loading gain reductions for 100-m-diameter antennas aredeveloped to compare a relatively heavy baseline reflector backupstructure with two lighterweight structures; all have equivalent,acceptable performance for gravity loading.

AN/TPS-59-A Unique Tactical Radar, L.E. Bertz & L.J. Hayes,GE-The AN/TPS-59 is a recently developed 3-D tactical radar thathas unique and advanced state-of-the-art features. This paper pre-sents a brief system overview along with pertinent mechanical de-sign constraints and features. Significant events in the developmentof the AN/TPS-59 radar are discussed and spin-off system config-urations are described.

Developments in Ground Mounted Air Supported Radomes,(M.B.Punnett, Birdair Structures, Inc., Buffalo, N.Y.-A review of someof the developments in air supported radomes which may be of in-terest for new designs. Variations in geometry and material are re-viewed. Long term exposure results and electrical performance ofHypalon, vinyl, and Teflon coated materials are presented. Guide-lines for reliable pressurization systems and methods of installationare outlined. The paper concludes with several examples of air sup-ported radomes, varying from an 8 ft., highly portable, militaryunit to the 138 ft. diameter torus installed on the CN Tower.

Structural Design Improvements of ESSCO Radomes and Antennas,J.B. Sangiolo & A.B. Rohwer, Electronic Space Systems Corp.,-Over the past decade, the ESSCO Metal Space Frame Radome hascontinually evolved. Design techniques, materials selection andmanufacturing innovations have contributed to a state-of-the- artproduct.

The report elicits the structural design improvements, as wellas the Manufacturing and Quality Control improvements whichhave been introduced, making the ESSCO radome a structurallysuperior, reliable product requiring little, if any, maintenance.ESSCO has taken advantage of the controlled environment pro-duced by the radomes in the design of the reflector backstructure,antenna pedestal and antenna servo system. The new ESSCO box-beam backstructure is detailed. The numerically controlled coordi-nate measuring machine which has enabled ESSCO to demonstrateits state-of-the-art reflector surface accuracy is discussed.

Preliminary field results from the performance of ESSCO radiotelescopes are already verifying a surface accuracy of better than0.13 r.m.s. and no loss due to tracking inaccuracies.

IMPACT OF SYSTEM REQUIREMENTS ON PACKAGINGDESIGN

The Mechanical Engineer's Role in Military Electronics, J.P. Karpuk& C. Levine, Raytheon Co., Wayland, Mass., -The paper discussesand illustrates equipment designed for radar applications, such assurveillance, land based and shipboard, air traffic control and earlywarning functions.

It highlights some of the examples of innovativeness demon-strated by mechanical engineers in the role of packaging equipmentfor military use in configurations such as:

* Shipboard equipment-above and below decks.* Tactical-mobile-deployable systems.* Fixed site-construction of a giant radar phased array.

Special attention is focused upon the design and cooling ofequipment enclosures.

Design and Fabrication of a Lightweight Radome for Use With theHemispheric Coverage Antenna, M. Costagliola, Sperry Rand, withR.C. Berg, Lunn Industries, Inc. -This paper describes design andfabrication of a unique dielectric radome which not only providesenvironmental protection but accurately locates 25,000 passivephase delay modules on its surface. The radome is 113" in diameter99" high and incorporates 106 circular lands on the inside skin toprovide channels for location of the modules. A novel tooling con-cept was developed, using an inexpensive "breakway" plaster moldto produce the dome. The final part met all dimensional require-ments and weighed only 330 pounds.

Challenges in Interconnection a Phased-Array Radar, P.J. Walsh &J.A. Henderson, Westinghouse,-A means of interconnection aphased array radar antenna for a new airborne radar is presented.Nearly 2000 phase shifters are to be individually controlled requir-ing that 6 connections be made to each of them. These connectionsare made through a 14 layer multilayer printed wiring board. Thelatest technology available for making the PWB and external cablingis described.

High-Voltage Packaging Problems for Airborne Systems, W.G. Dun-bar, Boeing Aerospace Co. -Methods are presented for packaginghigh-density, high-voltage, high-power parts and modules. Exampledesigns are shown for several mechanical conditions that involvehigh-voltage gradients through or across the surface of insulatingmaterials. References are given for test specifications for materials,parts, components, and systems to alleviate packaging problems inairborne systems.

An Improved Maintainability Concept for Advanced Radar Systems,H.W. Garner, Westinghouse-An improved maintainability concept ispresented for a very dense, complex digital signal/data processor inan airborne radar. The Line Replaceable Module (LRM) design con-cept, presented herein, results in a lower life cycle cost than isobtainable with conventional Line Replaceable Units (LRU's). Thisis achieved through fault isolation to the LRM by Built-In-Test(BIT) in the aircraft and replacement of the defective LMR at thislevel. Tradeoffs of weight, volume, and reliability are discussed todemonstrate the factors which led to the final design. A number ofnovel features which complement the overall design are discussed.

Crystal Oscillator Vibration Isolation for Airborne Radar Appli-cations, H. Rossman & J.J. Chino, Westinghouse-This paper dealswith a method for determining a vibration isolation system capableof attenuating airborne induced vibration imparted to stable crystaloscillators used in airborne radars. Suitable isolation is achievedwhen maximum permissible vlbration levels, based on system noiselimits, have not been exceeded.

Included in this paper is a procedure fot calculating the responseof multi-stage (or single stage) vibration isolation systems. Fore-most, the procedure considers the "real world" effects introducedby complex, nonhomogeneous structures. Essentially, the approachdepends on assuming a reasonable value for the occurrence of thefirst major structural resonance (not the isolators) and the ensuingselection of a damping ratio (p).

STRUCTURAL DESIGN

On the Design of Self-Deploying, Extremely Large Parabolic An-tennas and Arrays, A.A. Woods, Jr., & W.D. Wade, Lockheed-Adesign solution for a large aperture space antenna is presented. Thisis a self-deployable antenna within state-of-the-art technology. Thisdesign is being proven in independent research and developmentwork conducted at Lockheed Missiles & Space Company, Inc.,(LMSC). The antenna described in this paper is compatible withSpace Shuttle and usable at sizes up to 2000 feet in diameter forparabolic antennas and phased arrays. The availability of an an-tenna of this size removes a significant technology developmentactivity, space assembly and manufacturing, as a stumbling block forspace systems requiring extremely large aperture antennas.

ABSTRACTS 221

Antenna to IMU Mounting for SAR Motion Compensation, L.C,Miller & V.M. Foxwell, Westinghouse-Motion compensation fora synthetic aperture radar requires careful installation of the iner-tial navigation system (INS) used for sensing antenna motion.Limits on relative motion between the INS and antenna, and typi-cal environments are presented. An approach for analyzing the dif-ferential motion is discussed and two example configurations areconsidered. It is demonstrated that the mounting problem iscritical to good imaging performance but that acceptable perfor-mance can be achieved with reasonable designs.

Antenna/Mast Reguirements for Low Altitude Aircraft DetectionSystem, R.W. Milligan & D.J. Zona, SandersAssociate, Inc. -Thepaper describes the basic mechanical design philosophy of theLAADS mobile ground radar antenna system. Impact of speci-fied operational as well as environmental requirements upon thephysical development of the antenna system are outlined and theireffect discussed. The selected methods of achieving the majorantenna system functions, including automatic deployment, level-ing, rotation, stow, and locking within the context of specified re-quirements are also detailed. A critique of the implemented anten-na system after exposure to specified environmental testing andnine months of operational field service concludes the paper.

Conceptual Studies for Unmanned Hardened Radar Facilities, R.W.Luff, J. Antebi & H. Simpson, Simpson Gumpertz & Heger Inc. -Abaseline design concept is developed for a hardened, unmanned,phased-array radar facility. Among the subjects discussed arefunctional design requirements and constraints, concepts examin-ed, design trade-offs, and special considerations and problemsassociated with the structural design. The selected configurationis described and a parametric study of the adaptability of the base-line design to varying levels of nuclear threat is discussed. Prelim-inary cost estimates are presented. While this study is performedfor a specific facility, the method of approach is readily adapt-able to other hardened facilities.

Of special interest is the reliability analysis which was devel-oped for multimode of operation systems, using Markov processestheory; this is described in some detail.

Evaluating Computed Distortions of Parabolic Reflectors, M.S.Katow, JPL -Distortion outputs from structural analysis of a 64-mparaboloidal reflector are analyzed by two computer programs fortheir radio-frequency performance characteristics. The computedand field measured values are compared.

Antenna Bias Rigging for Perfonnance Objective, R. Levy, JPL-An optimum bias rigging for a paraboloidal antenna can be used tominimize the expected average mean-square half-pathlength surfacedeviations. Statistics of deep space planetary missions are em-ployed to develop weighting factors for antenna elevation anglesduring these missions. A prodecure is shown to compute the op-timum rigging angle from these weight.

Design of Hardened Radar Structures, R.L. Mann, GE-The struc-

trural design of an "edge-supported" phased-array antenna is dis-cussed in some detail. A technique is presented for separately ac-

commodating combined airblast loading and thermal radiation ef-fects. Material strength at elevated temperature is shown to be amajor concern in hardened design, along with degradation in surfacereflectance for materials exposed to direct thermal radiation. Rockdebris studies are being conducted to determine behavior duringimpact with simply supported beams.

Low-Cost Approach to Large Survelliance Antenna Pedestal, E.C.Hawkins, Bendix-A low-cost surveillance radar pedestal, designedfor low quantity production, is described. The design maximizesthe use of standard commercial components and eliminates specialtooling. The unit's adaptability to various drive units, rotary coup-lers, position data encoders and twoer mountings is discussed. Also

included in the design is the possibility of incorporating or retro-fitting dual drives for additional power and/or low backlash appli-cations. The selection of such features as adjustable gearing back-lash, three-point tower mounting, drive-unit slipclutch, levelingshims instead of built-in jacks, turn-of-the-wrench bolt tensioning,and the use of weldments and parallel plane machining is discussed.

THERMAL CONTROL

Thermal Design of Airborne Radars-Present and Future, F.E.Altoz, Westinghouse-The significant factors relating to the thermaldesign of radar equipment is presented along with an identificationof potential areas for improvement. The cooling techniques de-scibed emphasize the microcircuit packaging area, one which im-pacts the greatest on radar system reliability. The paper also ex-amines emerging developments most likely to influence the futurethermal design of radars.

Heat Pipe Applications to Control Electronics Temperature inRadars, K.S. Sekhonn, Hughes-The advancement of electronicstechnology and increase in power densities appears to go hand inhand. The trend is to dissipate 10 watts of power in a 5 watt elec-tronics package. This demands new and sophisticated thermal pack-aging techniques to cope with increasing requirements of heat dis-sipation. Heat pipe provides a promising technique to achieve highdensity packaging and still maintain reasonable operating junctiontemperatures. A number of heat pipe development studies, to re-duce overall thermal resistance from junction to ultimate heat sinkfor electronics, have been conducted at Hughes-Fullerton. Theseelectronics are utilized for surveillance, early warning, fire con-

trol, and navigation from both shipboard and airborne platforms.The results of these studies are presented in the proposed technicalpaper.

Temperature Control of Highly Sensitive Electronic Devices, J.J.Chino & H. Rossman, Westinghouse-This paper will discuss closedloop, fast response thermal regulator design and operation. Thiswill be accomplished by considering the various elements of theloop and discussing them with regard to stability during constantenvironmental conditions, stability during abrupt changes in en-

vironmental conditions and gain. Further, location of the sensorwill be discussed with regard to its dependence on the isothermalpattern of the device. Also included in this paper will be the dis-cussion of a procedure for defining the essential mechanical loopparameters so that a suitable regulator can be designed.

A Heat Pipe Application to a Radar TX Cabinet, U. Corsi & G.Malagoli, Selenia Industrie Elettroniche A ssociate, Italy-This papercovers the design efforts and results attained in the application ofan heat pipe to a radar TX cabinet to cool and soundproof the sys-tem.

At the starting conditions, a blower, located in the TX cabinet,provides to cool the magnetron cavity with high air delivery andhead, thus producing a high whistle.

The heat pipe is being applied to transfer the heat from the mag-netron tuning to the other edge of the pipe whereto a copper-fin-ning has been welded.

After a thorough examination, the following problems have beensolved:

1 -the development of a particular type of heat pipe in coopera-tion with the supplier;

2-a system designed to connect the heat pipe with the magne-tron tuning area;

3-an appropriate thermal connection of the magnetron withthe heat pipe.

Controlling Temperatures in Phased Array Antennas, R.F. Porter,Westinghouse-Phased array antennas are notoriously sensitive toboth temperature variations and gradients. At the same time, thereis always the desire to operate at as low a temperature as possible.

IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS VOL. AES-14, NO. 1 JANUARY 1978222

A new and rather novel technique is described whic-h will meetthese requirements in an environment ranging from -54°C to+1250C. In addition, it maintains the antenna at temperatureslower than the ambient without using any electrical power.

"Opence" (Optimum Performance) Heat Sink Design Procedure,M. Tadmor & H. Frenkel, ELTA-"OPENCE" is a design procedurefor heat sinks. The procedure is intended for forced air coolingsystems and is presented as a step-by-step design method which isvery accurate and easy to follow;

For those interested in pursuing the development of "OPENCE"in depth, a full mathematical analysis is presented at the end of thearticle.

"OPENCE" was developed as a design tool for wide use. It re-quires, however, the use of an electronic calculator, preferably hav-ing a hyperbolic tangent function capability.

ANTENNA POSITIONING AND CONTROL

E-3A Antenna Pedestal Turntable, C.M. Fritz, Keystone Engineer-ing Company-The development of an airborne 4 point contactmoment load bearing, employing hollow ring sections is described.The E-3A (AWACS) Antenna Pedestal Turntable transfers the aero-dynamic loads from, and provides rotation to the 30 ft. diameterrotodome, mounted on the Boeing E-3A (modified 707) airplane.As an aircraft structure, Boeing engineering support includedmaterial selection and stress, fatigue, failsafe and finite elementanalyses. Keystone Engineering followed a test and extropolationapproach. Turntable moment loads cause ring prying. The result-ing ring distortions affect the bearing race geometry, and ball laoddistribution, hence bearing life. Rotation subjects the rings tofatigue. Concentrated load points affect the limit load racegeometry. Bearing performance and stiffness are traded offagainst weight.

Shock Mounts for Shipboard Radar Pedestals and Stable Platforms,L. Fuss, Scientific-Atlanta, Inc. -The need for and implementationof shock and vibration isolation of antennas and stable platformsis related to accuracy, the force and motion environment, controlsystem performance and protection of sensitive instruments. It isconcluded that an isolator must be stiff rotationally to assureaccuracy and performance and must be flexible translationally toaccommodate shock and vibration motions. A linkage suspensionis proposed which has these characteristics, and its force-displace-ment and force-velocity relations are derived. Rotational stiffness,weight and snubbing are considered.

Radar Azimuth Bearings-Design, Selection and Application, T.A.Bushar, Keene Corp. -A summary of the state of the art is pre-sented. Much useful design and application information is providedto aid the radar structure designer in matching azimuth bearingdesign to performance requirements. Special emphasis is given tothe importance of communication between the engineers of theradar manufacturer and the bearing supplier.

Slip Ring Assemblies for Radar Antennas, H.C. Walker, S.R. Cole,& S.L. Brady, Litton-The design considerations for slip-ringassemblies used in radar antennas are presented. Contact selectionand configuration are discussed along with the effects that the en-vironment (e.g. mositure) can have on contact performance. Designconcepts for power circuits, low frequency signal circuits and highfrequency signal circuits are discussed along with methods of savingspace, designing for ease of maintenance and meeting the mechani-cal requirements of shock and vibration. The importance of theslip ring engineer having the electrical, mechanical and environmen-tal requirements at the early design stages is emphasized.

Radar Antenna Stabilization on Naval Ships by a Tilted Axis Con-fi'guration, W.D. Delany & R. Wilson,Admiralty Surface WeaponsEstablishment, UK-A description is given of a novel mechanical

configuration for mounting a large surveillance radar antenna on aship at masthead height so that rotation of the antenna is alwaysmaintained about a vertical axis.

The design gives a reduction in weight, and its improved accessi-bility simplifies maintenance. A mathematical theory is given forthe conversion of axes angles. A scale model, fully engineered asregards the servo drives, was constructed and evaluated on a labora-tory rolling table. Some results are given of the dynamic testscarried out.

Static Mass Balancing with a Torsion Spring and Four-Bar Linkage,W.A. Harmening, RCA -Two planar four-bar linkages are presentedfor use with a torsion speing to overcome static mass unbalancetypical of steered radars. This arrangement replaces the dead loadof a counterweight without increasing the steered mass or inertia.

Impact Loads on Radar Director-Geared Systems, K. Redmond,Lockheed-The design of the Radar Director-Geared System invol-ves a thorough evaluation of gearing loads that result from directordynamics, as well as the general requirements for satisfactory per-formance under severe environmental loading. Part of this evalua-tion should include the determination of impact load torques re-sulting from rapid drive reversals that occur during target acquisi-tion, scanning, and slewing modes of operation. This paper pre-sents a method for calculating peak-transmitted torques under theseconditions.

High Accuracy Hydraulic Motors for Radar Antennas, C. Ekenberg,P. Str6n, B.-O. As, Philips Elecktronikindustrier AB, Sweden -Philips Elektronikindustrier AB, PEAB, has developed, engineered,and manufactured a line of hydraulic motors for use with radarantennas, in particular in shipborne Weapon Control Systems. Sam-ple designs are presented in some detail along with the rationalefor adopting this technique. Special emphasis is given to a design,which in one package contains a number of functions: motor, bear-ing, angle pick-off, electrical signal transfer through a slipringassembly, oil transfer through "hydraulic sliprings", and the servovalve.

ENVIRONMENT AND MATERIALS

Advanced Composite Antenna Development, J.H. Heathman & R.S.Wilson, General Dynamics Convair Division -This paper presents adesigned, fabricated, and tested antenna terminal employing advan-ced composite materials. The antenna demonstrated the advantagethese materials have in providing a more compact, lower weightsystem, while meeting required performance in a cost effectivemanner. This work was speciflcally oriented toward the require-ments and objectives of the Naval Electronics Command for thedevelopment of a lightweight, low-cost, and maintenance-free satel-lite communications (SATCOM) antenna. The antenna has beenidentified by NAVELEX as a future requirement for use through-out the fleet. Vibration testing was performed by both Convair andthe Naval Electronics Laboratories Center (NELC), San Diego. Theantenna structure successfully passed the vibration testing withrecorded structural resonant frequencies in all three axes in excessof 45 hertz. The structural also successfully survivied shock testing,medium-weight hammer, at NELC.

Battle Damage Survivability for Consideration in The Design ofRadars, M.L. Salive, H.L. Wolk, & S.L. Wang, David W. TaylorNaval Ship Research and Development Center with W.R. Coggins,Naval Sea Systems Command-This paper discusses mechanicalcharacteristics of radar systems in a battle environment. The needfor Navy radars to survive the threat posed by nearby bursts of war-heads makes it imperative that mechanical engineers conscientioulyincorporate survivability factors in their design.

Custer Horn: A Novel Application of Fiberglass Structural Com-posites, T.L. Ryan, NSWS with W.B. Hebenstreit, Structofab, Inc. -

ABSTRACTS 223

A method is presented for solving a severe corrosion problem byreplacing an aluminum radar horn with one made of fiberglass re-inforced plastic. The original horn was made of aluminum andaluminum honeycomb panels screwed together. Key design andmanufacturing problems engendered by the conversion from metalto fiberglass and by the requirement for mechanical and electricalinterchangability are presented. Solutions discussed include:achievement of an accurately formed, interior conductive surface;protection of the conductive surface from corrosion and delamina-tion; conductivity-heat dissipation-weight-delamination resistancetrade offs in conductive surface design; strength-stiffness-weight-thickness trade offs in side wall design; moisture drainage andpressure limitation; shock resistant anchoring of mounting brackets.

Composite Structures for Naval Pointing Systems, D.C. Brecht,GE-As a step toward the development of lightweight pointing sys-tems for future high speed Naval vessels, General Electric OrdnanceSystems developed and fabricated a radar director train yoke struc-ture made from graphite/epoxy composite materials. On an equalstiffness basis, this composite train yoke design is 35 percent lighterthan a conventional steel yoke. Introduction of composite struc-tures on shipboard pointing systems should be accomplished on a"selective reinforcement" approach. A significant problem area isthe impact strength of surfaces to falling objects or accidentalblows; the use of special outer layer materials show promise as asolution. The use of truss structures instead of monocoque con-struction may be a more efficient use of composite materials.

Development of a Fiber-Reinforced Composite Design Concept forLarge, Mechanically-Scanning, Planar Slot Arrays, J.W. Small,ITT-Results are presented of the first phase of a study undertakento investigate the technical and economic feasibility and impact ofAdvanced Composites on the design of large Radar Antennas forunprotected worldwide shipboard service.

The linear slotted waveguide array element was selected as thecritical component for initial development. A current productionRadar System is used as the technical and cost base. The design,fabrication, and test of the Composite waveguide are discussed indetail. In addition, cost and weight comparisons between the com-posite design and the baseline are presented.

Corrosion Protection for Shipboard-Mounted Antennas, A.W. Kline,Lockheed-This paper presents several methods for protecting ship-board-mounted antennas from the corrosive effects of the opera-tional environment. These methods include a new paint system,corrosive-resistant electrical connectors, and special considerationsfor waveguide and critical assemblies.

The Manufacture of Airbome Cassegrain Antenna, J. Shalit, EL TAElectronics Industries Ltd., Israel-This paper describes the proceed-ure tools and materials used in the production of a cassegrain anten-na. The lamination process and the instaUlation of the polarizationwires are described precisely. Special attention has been given tothe tools involved.

REPRESENTATIVES

AUTOTESTCON Board of DirectorsOrland R. BatchelderFred LiguoriMatthew F. Mayer

EASCON Board of Directors, David W. Lipke, ChairmanMyron A. RosenthalDavid A. Wilkinson

NAECON Board of Directors, James E. Singer, ChairmanMichael T. ColemanKenneth B. Olson

WINCON Board of Directors, Max T. Weiss

Education Committee, H.A. Manoogian

National Voluntary Metric Conversion BoardA. T. Campbell

Technology Forecasting and Assessment CommitteeGeorge AbrahamMorton Foxe

Intersociety Energy Conversion Engineering Conference,Daniel S. Go/din

Oceanography Coordinating Committee and Offshore TechnologyConference, Arthur Westneat

Technical Activities Board Transportation Committee, K.B. Olsen

Communications Society Conference BoardStephen RiterRobert W. Rochelle

Energy CommitteeWalter E. Morrow

Technical Activities Board Urban Technology Committee, Open

Technical Activities Board Environmental Quality Committee, Open

IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS VOL. AES-14, NO. 1 JANUARY 1978224