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This report details tne results or a study that was conducted in the application of wavelet transforms to the processing of digital reconnaissance imagery. Although the major emphasis in the study centered on General Frame wavelets, orthonormal wavelets (Daubechies) were also implemented. The study results led to the implementation of a set of wavelet based tools to be included in the Image Processing Toolkit at Rome Laboratory. Some of the tools were designed to aid in the visualization of the interaction of the wavelet transform and imagery. Other tools were designed to provide different views of the imagery (such as pseudocoloration) and to enhance certain image features based on the localization property of the wavelet transform.

This Final Technical Report covers the integration of oxide ferroelectric thin films (e.g. bismuth titanate = Bi4Ti3Ol2 = BTO or lead zirconate titanate = PZT) into the gate dielectric of a metal-insulator-silicon field effect transistor (MISFET), capable of functioning in a non-volatile, non- destructive readout (NDRO) ferroelectric random access memory (FERRAM). Also provided is a detailed description of the test vehicles implemented for the study of fabrication process integration and optimization and the resultant properties of ferroelectric/(semiconductor) memory FET (FEMFET) and related structures. The Interim Report covering the first phase of this contract described an investigation of UHV-deposited ferroelectric fluoride (BaMgF4 = BMF) films as gate insulators; however, BMF transistor structures exhibited rather poor reproducibility, and electrical instability manifested as poor retention capability. Results of the second phase of this program are presented in this report, which focuses on exploration of oxide ferroelectric films for the FEMFET gate dielectric. There is growing evidence that layers of ferroelectric oxides, when suitably processed may possess switching and stability properties that are far superior to those attainable with BMF layers.

This Interim Technical Report covers the development and integration of Barium Magnesium Fluoride (BMF) ferroelectric thin films for incorporation into the gate dielectric of a metal-insulator-silicon field effect transistor, capable of functioning in a non-volatile, nondestructive-readout (NDRO) ferroelectric random access memory (FERRAM). Also provided is a detailed description of the test vehicles implemented for the study of fabrication process integration and optimization and the resultant properties of 'ferroelectric/(semiconductor) memory FET (FEMFET) and related structures'. Tne BMF films were deposited by co-evaporation in ultra high vacuum from barium fluoride and magnesium fluoride effusion sources. A substrate temperature of 200 deg C during deposition followed by an anneal in hydrogen at 480 deg C resulted in polarization orientation closest to the preferred. Film samples exhibited polarization, Ps, as high as 4.55 micro-C/sq cm. The permittivity varied from a value of 9 at 5 kHz to 8.4 at 500 kHz. This compares closely with the average value of 10 reported for bulk single crystals. The ferroelectric switching speed of the thin film was approximately 45 nanoseconds.

This report has been prepared to summarize the technical study performed to determine the reliability characteristics of advanced technologies. The study covered existing reliability models and the development of new models. The devices that were investigated were: Very Large Integrated Circuits (VLSI), Memory Circuits, Hybrid Circuits, Microprocessors, and Gallium Arsenide Microwave Monolithic Integrated Circuits (GaAs MMIC). Packaging, environmental quality, and maturity were other factors that were considered in this investigation. The results of the study are: reliability models that extend the range of MIL-HDBK 217, end of life predication models for in-depth circuit and packaging design and new factors quality assessment. These data will be transitioned from the report to MIL-HDBK 217 for use by government and contractor personnel in estimating the reliability of new equipments. Keywords: Reliability, Computer hardware, Failure rate, VHSIC, GaAs, Hybrid, Gallium Arsenide, Microelectronics, Memory devices.

This preliminary report considers modelling of two classes of video trackers from their algorithmic and measurement aspects. Because they are widely used and easily implementable in hardware, the classes chosen were the binary centroid tracker and the binary correlation tracker. Many variations exist even in these classes; their value in the present setting is to demonstrate the modelling aspects and the salient features that may be derived from an analysis of the behavior of these systems in the presence of noise. The models predict tracker offset errors (mean error) and track point jitter (the standard deviation of the error). Track performance, in general, is dependent on the character of the object pattern being tracked and on the distribution of the noise associated in the formation of the array of pixels which represent the pattern. In the analyses which follow, a simple square pattern is used and Gaussian additive noise is assumed. The models permit any geometric pattern as input and the question of noise distribution and false alarm in the formation of the binary pattern from the linear data input. Additional keywords: Computations, and Equations.

We have studied the electrical and optical behavior of specimens from a 3x5 matrix, considering three deposition temperatures. In addition to a set of unannealed specimens at each deposition temperature, four sets of annealed samples were prepared at each temperature, for high and low temperature treatments in hydrogen and in nitrogen. By excluding results for specimens prepared at 750 Deg. C, except those receiving anneals at 1000 Deg. C in either hydrogen or nitrogen, we found clear direct effects of annealing on all the parameters of preliminary interest. The results of spectroscopic ellipsometry analysis indicate that the film structure of the specimen with the baseline silicon nitride is significantly different from the films deposited at higher temperature. It does not have an ellipsometrically detectable layer of silicon dioxide at the silicon surface. The stability of the memory states associated with the pulsed write and clear conditions correlated with the final density of fast surface states, except for anomalous behavior of the 750 Deg. C, unannealed specimen. (Author)

Solid-state power generation techniques are presently available which allow for the generation of high peak power in the S-band frequency domain. Transmitters so configured would have inherent advantages of ruggedness, improved reliability, simpler modulation, and total use of low voltage supplies which would make it an excellent replacement for thermionic transmitters presently used.

This report describes a study performed to determine the nature of scattering of ILS radiated signals by objects on the airport property. These included both taxiing and overflying aircraft. The interaction of this scattered energy with the direct radiation was studied to determine the derogating effects of ILS guidance. This resulted in the development of four system level concepts for detecting glide path derogation. One technique, the Vector DDM, was selected as being most practical from a sensitivity, reliability, and cost point-of-view. (Author)

The objective of this study is to investigate the feasibility, practicality, and implementation of standard electronic modules (SEM) for avionics. Tradeoff studies are used to provide quantitative SEM format(s). The broad spectrum of considerations necessary to characterize standard packaging for a wide class of avionics applications are investigated. In depth quantification is placed primarily on digital signal processing and to a lesser degree on analog circuitry. The work is performed in four tasks whereby Task I evaluates current and past industry and DOD module programs, Task II studies present technology and technological trends for determination of the standard avionics module(s), Task III is a compilation of industry and DOD data concerning standard module information and concepts, and Task IV is the detailed development and evaluation of the proposed 'Westinghouse SEM' including the construction of demonstration hardware. The efforts of Tasks I, II, and III are described in the previous issued interim Report AFAL-TR-76-61, Volume 1. This Final Report describes the details of the study performed on Task IV with the conclusions made and recommendations for future work. (Author), See also Volume 1, AD-A027 520.

The objective of the study is to investigate the feasibility, practicality, and implementation of standard electronic modules (SEM) for avionics. Tradeoff studies are used to provide quantitative data to assist the Air Force Engineers in selecting the SEM format(s). The broad spectrum of considerations necessary to characterize standard packaging for a wide class of avionics applications are investigated. In depth quantification is placed primarily on digital signal processing and to a lesser degree on analog circuitry. The work is performed in three tasks whereby Task I evaluates current and past industry and DOD module programs, Task II studies present technology and technology trends for determination of the standard avionics module(s), and Task III is a compilation of industry and DOD data concerning standard module information and concepts. The report describes the details of the study with conclusions made and recommendations for future work to be considered.

Many changes have taken place in airborne radar antennas since their beginnings over forty years ago. This lecture includes a brief historical overview of the advances in technology from mechanically scanned reflectors to modern multiple-function phased arrays. However, emphasis is not on history but on the state-of-the-art technology and trends for future airborne radar systems. The status of rotating surveillance antennas is illustrated by the AN/APY-2 Airborne Warning and control System (AWACS) slotted waveguide array, which achieved a significant breakthrough in sidelobe suppression. Gimballed flat-plate arrays in nose radomes are typified by the AN/APG-66 (F-16) antenna. Multifunction phased arrays are represented by the Electronically Agile radar (EAR) antenna, which has achieved significant advances in performance versatility and reliability. Trends toward active aperture, adaptive, and digital beamforming arrays are briefly discussed. antennas for future aircraft radar systems must provide multiple functions in less aperture space, and must perform more reliably., This article is from 'Microwave Antennas for Avionics. Lecture Series of the Avionics Panel and the Consultant and Exchange Programme Held in Rome, Italy on 7-8 May 1987; Guenzburg, Germany on 11-12 May 1987 and Ankara, Turkey on 14-15 May 1987,' AD-A185 152, p2-1-2-7.

A dipole was recently developed for use in a phased array at 420 to 450 MHz. It was designed to scan + or - 40 degrees in elevation and + or - 48 degrees in azimuth. The data presented includes analytical simulation, VSWR testing of the dipole both isolated and in simulators, and patterns measured with a finite array. The simulators include single and dual mode devices as well as two 11-element columns. The extensive simulator work was necessary partially because of the small size of the array. The columns were used in conjunction with computer analyses to determine VSWR throughout the scanning coverage. The data from various sources agrees well, and predicts that the VSWR across the frequency band across all scan angles will be less than 1.9:1. (Author), This article is from 'Proceedings of the Antenna Applications Symposium Held at Monticello, Illinois on 21-23 September 1983. Volume 1,' AD-A142 003, p99-118.

A computer-controlled g-sensitivity measuring apparatus has been assembled and used to screen 100 MHz AT-cut crystal units for any manufacturing defect. This apparatus obtains the g-sensitivity vs. acceleration characteristic of a crystal unit alone in less than 100 seconds in a given direction. The basic equations governing computation of g-sensitivity from the measured data can be used to determine a new set of component requirements for the apparatus when measuring different crystal types to a specified g-sensitivity level. It has already been shown that measurement of g-sensitivity levels less than 10 to the minus 11th power is possible for 100 MHz quartz crystal units. The described g-sensitivity measurement technique can be used to study mechanical resonance properties of crystal mounting and packaging schemes, simply screen defective crystal units, or investigate interfering modes of low frequency mechanical resonances of the crystal plate and supporting systems after a simple modification of the measurement software., This article is from the Proceedings of the Annual Symposium on Frequency Control (37th), 1-3 Jun 83, Marriott Hotel, Philadelphia, Pennsylvania, AD-A136 673, p284-289.

Details of the design for a highly stable voltage-to-current convertor are described. The converter can be used in a new design for a gyrator which minimizes the negative-resistance problem, and increases the integrated-circuit yield. Pole-zero cancellation can be used to broadband the converter. (Author), See also Quarterly Rept. no. 1, AD-851 134.

This report covers an investigation of pulse leveling techniques applicable to high power radar modulators. It defines the problem areas in achieving precise pulse shape control in high voltage and high power pulse generation and presents techniques for overcoming the difficulties defined. Significant contributions are made to the state-of-the-art through the gathering together of diverse information into one place. The attainment of precise pulse control in a high power radar modulator is the result of careful attention to all facets of transmitter operation as well as the design of the modulator itself. The energy state and response time properties of the entire power system extending from the primary power source through the video circuit of the RF amplifier load are examined in detail in an analysis of their effect on total modulator performance. Techniques for improving modulator performance based on this analysis are described and representative designs for a line type and hard tube modulator pulsing a linear beam are outlined. (Author)

An analysis is presented of the operation of ruby and of neodymium glass in short pulse, high power laser application as a step toward a design concept for 0.1 microsec, 10 to the 7th power joule, 1/100,000 radian optical radiation system. The device conceived consists of several separate identical oscillator-amplifier combinations operating mutually incoherently but individually coherent with a 10 cm aperture. Ruby is the selected laser material pumped with xenon flash lamps and arranged in a unique array geometry. (Author)

This report contains a description of the models to be used in analyzing the capabilities of ground-based sensors in determining the mass of orbiting bodies, model coefficients, and the justification for their selection. Relations are derived for computing sensitivity coefficients and their coupling to mass variance.

The report contains a description of the models to be used in analyzing the capabilities of ground-based sensors in determining the mass of orbiting bodies, model coefficients, and the justification for their selection. Relations are derived for computing sensitivity coefficients and their coupling to mass variance for the case of noisy, biased sensors (monostatic and tri- static radars, Baker - Nunn cameras), and for spherical and tumbling cylindrical satellites., See also Volume 1, AD669359.

Contents: Materials research Electroluminescence Ferroelectrics Laminar screen development Model fabrication Signal distribution Ionic switch material distribution Ionic switch operating life Ionic switch encapsulation

Improvements of the tape storage camera tube increases the resolution from 40 to 75 line pairs per millimeter for small rasters at 5% response. Response curves showing 60 line pairs per millimeter at 10% response were measured. No grating disturbance or any effect of grating orientation was observed. The hard copy film photo of the display kinescope showed 23 line pairs per millimeter (retina dimension) resolution, 8 shades of gray resolvable by the eye, and a contrast of 80 percent. When the stored picture was underscanned by 18X to show only the AF test pattern, 64 line pairs per millimeter were resolved. Photodiodes were made to test the image section operation. Aperature response curves had a 5% response of 98 line pairs per millimeter, which when corrected for the aperture response of the lens became 220 line pairs per millimeter. A technique was developed for measuring the aperture response curves of lenses and image displays. Studies indicated that a mechanical means (harmonic drive) may be the best for smooth tape drive.

Investigating techniques were continued for ferromagnetic parametric amplification in the millimeter-wave frequency region. Experimental correlation was obtained for the 8mm data. New data was obtained for 2 mm, H Ho. A method for establishing an operating point is described. A rod size is shown which will support three appropriately chosen simultaneous electromagnetic resonances. Work has begun on the dielectric rod structure as a means of treating the more difficult case of the ferrite rod. Similar feeds are required for analogous modes. Analysis of the dispersive properties is much simpler and is available from a number of previous studies. An operating point is chosen from a knowledge of the dispersive behavior of the dielectric rod. The magnetodynamic mode chart is completed. Charting over a wide frequency range has permitted close correlation with the theoretical Walker mode spectrum at low frequencies and good agreement with predicted modes of the dielectric sphere resonator at high frequencies.

The report describes the modification of the AN/TPS-61 radar for hostile weapon location and the subsequent testing at Dahlgren, Virginia and Fort Sill, Oklahoma. The objective of the program was to determine hostile weapon location effectiveness, evaluation of mission data, and recommend system improvements. The radar system, test environment, test results, operational considerations, and recommended improvements are described. Performance against all three classes of field artillery (mortars, howitzers, and guns) was evaluated. In addition, the TPS-61( ) was evaluated as an Air Surveillance Radar (ASR).

This report describes a synthesis technique for redundant multiple line networks which determines the optimum placement of restorers for minimum cost. The cost expression is a function of system reliability, cost of implementation, weight, power, and speed. The redundant networks are required to have the same order of redundancy throughout, but otherwise the form of the network is restricted very little by the synthesis procedure. The procedure is developed in sufficient detail for application to sample networks and for implementation on a computer. A prime requisite to the synthesis procedure is a means for predicting the reliability of multiple-line redundant networks. A new technique for performing this operation is presented in this report. It is applicable to multiple line net works of almost any configuration.

Modular arithmetic concepts and associated computation techniques and organization are outlined. Fundamental operations of modular arithmetic discussed include sign or relative magnitude determination and division, mathematical solution using modular arithmetic, techniques for efficient mechanization of modular arithmetic adders and multipliers, and organization and control of a modular arithmetic computer. Numerical analysis studies yielded novel results including the introduction of signed residues, overflow detection techniques, and a division algorithm 3 times as fast as any previously disclosed. A square-root algorithm which is considerably faster than the Newton-Raphson algorithm is discussed. Implementation techniques are described for trading speed for complexity, programming a computer to extend its range, and design techniques for reducing component counts in adders and multipliers. A functional simulation of modular arithmetic computation in a conventional computer is described, and statistical data on the operation of the various algorithms is included.

Preliminary design parameters were established for a traveling-wave configuration of the 70 gc maser. The feasibility of using a traveling wave structure depends critically upon the avail ability of a suitable isolation material and upon the development of microwave matching techniques. Several ferrite isolator materials have been tested as a function of resonant frequency versus magnetic field at room temperatures and at liquid helium temperatures. Rutile maser materials, having a very high dielectric constant, are difficult to insert into the microwave circuitry without causing very large mismatches. There fore, the design of proper matching devices and configurations has been of primary concern during this period. A computer program was established during this period to solve the steady state rate equations for the iron ion in rutile. Since the relaxation rates are not known with sufficient accuracy, the results of the program are somewhat inconclusive.

The study, the design, and the development of a high power solid- state radar modulator operating into a resistive (dummy) load, including, the study and experimentation performed on the individual inductive and solid-state components are described. The seriesing of trinistors, as well as trinistor characteristics are described in considerable detail. Finally, the modulator breadboard is described and evaluated. The breadboard develops 5 Mega-watts of peak power and operates at 300 pps. The pulse width is approximately 5 micro-seconds.

The first reporting period was devoted to establishing possible maser pumping schemes and obtaining instrumentation for experiments at frequencies near 140 gc. Tests were made, using the iron ion in rutile as active material, to determine if maseraction could be expected at the proper frequency. A sample of iron-doped zinc tung state was obtained and tested; however, it does not appear to offer any significant advantage for millimeter maser development over iron doped rutile. The IBM 7090 computer facility at Air Arm has been programmed to obtain transition probabilities for iron-doped rutile. These transition probabilities are necessary in order to understand more easily the operation of millimeter wave masers. To date, only the simple 3-level-type maser has been investigated, but analysis of the more complicated 5-level maser will be attempted.

Various approaches to the study of properties of semiconductor surfaces are taken up, in particular, the very sensitive electrical-frictional probe which is applied to the study of defects and processing technology under various conditions. The distribution of failures in the manufacturing and testing phase of two military systems are compared, and the factors described which caused failure ratios in the one to e one-seventh those in the other. By various studies, it has been determined that the aging of a semiconductor surface does not take place uniformly, but occurs differently at different regions on the surface. The effect of different types of etching and processing solutions on the photovoltaic response of the surface at individual points is used to investigate the nature of the aging and chemical changes on the surface. Characteristic changes in transis tor performance have been demonstrated from the charging of passivating layers by electrons or ions, from the frictional effects of loose desic cant under vibration, from ultraviolet light, and from steep transients in the non-overload range. In all cases, recovery occurs by a relaxation mechanism, which, if translated to the manufacturer's carefully planned ambient environment, involves time constants often of days or months., Unclassified report

Efforts were continued on the design of a family of microelectronic blocks for time and frequency control equipment. A listing of the load requirements for each circuit was assembled. The various microelectronic fabrication techniques of packaging were evaluated. A flat package of the order of 1/2 x 1/2 x 1/10 in. is recommended to package e circuit. The packages should be interconnected on three sides by printed circuit boards and assembled into a module. The Amp Meca interconnection method is recommended. Designs were completed, temperature tests were made, and specifications were written for the following circuits: decade divider (includes flip-flop and gate), digital gate, universal amplifier, analog gate, and squaring circuit. The microminiature crystal filter evaluation is substantially com plete. Current results show crystal filter performance to be superior to other approaches though filter size is larger than is desired. Special purpose circuit designs are under evaluation.

C ONTENTS: Ionic switches Electrostrictive witches Ceralectric cells Ferroelectric structure test Ionic switch tests Sandwich fabrication Sandwich evaluation

The use of photoemission as a method of converting solar photon flux into electrical power and the development of a high power-per-unit-weight unit suitable for space use are considered in this study. Experimental results using the WX-3964 photogenerator are presented, showing that one tube, having a relatively wide spacing of 70 mils, supplied output power of over 125 microwatts at an efficiency of 0.01 percent. A description of an experiment in the bell-jar processing station is presented herein, and the operation of the automatic readout experiment is described. Steps leading to the manufacture and processing of the anode and photocathode are described, as well as the construction of the WX-4209, a thin glass-sandwich photogenerator. Changes in processes and procedures are noted, and work leading to an equivalent circuit for the photogenerator is given., Sponsored in part by DARPA.

This report analyzes the potential application of communication, navigation and surveillance telecommunications systems to U.S. Coast Guard programs. The intra-Coast Guard ship/shore communications can be cost-effectively met by military satellite systems. As commercial maritime communications shift to satellites, the Coast Guard interface in the areas of MIB, AMVER, METEO and SAR can best be handled through the appropriate public correspondence satellite system. LORAN-C and OMEGA are the preferred alternatives to meet the navigation requirements in the coastal/confluence and high seas areas through 1990 unless the military GPS system is made available to the general public with acceptable user costs in the 1980's. Non-cooperative satellite surveillance techniques are not feasible for operational implementation in the near term. Sensor R and D should be continued/directed toward high altitude aircraft implementation. A cooperative satellite surveillance system is feasible and could be highly effective assuming international agreement. Dedicated USCG satellites are not cost-effective compared to systems provided by other agencies or organizations. (Author)

Work has continued on the parallel-pumped magnetodynamic amplifier utilizing the dielectric rod uniform precessional mode resonance. In an initial analysis, the pump power has been com puted and is presented in curve form in terms of the dielectric resonator Q and ferrimagnetic line width. The computer solution is given for the propagation characteristics of a dielec tric rod. The curves for the dielectric constant of most immediate interest (epsilon 13.5) are corroborated by experimental spectroscopy of Stycast. Dielectric continuity with YIG makes this material appealing for the design of resonant structures capable of supporting simul taneous electromagnetic and magnetostatic resonances. Results of loss tangent measurements of Stycast and other materials are given for 70 kmc and scale frequencies. Ways of coupling energy into the dielectric and magnetostatic modes were studied; experiments are discussed which resulted in the decision to couple to the pump mode from an iris in the side of the wave guide into the end of the rod and to couple to the YIG sphere directly from the side. (Author)

An investigation of the preparation of a silicon wafer surface prior to the application of photoresist to improve the resist adhesion is reported. Several process variations for obtaining oxide surfaces are investigated and correlated with resist adhesion. Methods of mechanically and chemically conditioning the oxide-passivated surface of the wafer to improve the adhesion of resist are investigated. The effects of varying the resist coating thickness and the use of various chelating agents, wetting agents and surfactants to find a linkage to bond the open chain-end of the resist to the surface of the oxide are studied. Procedures are evolved, and those used in the testing program are described. In this report, the use of Kodak Metal Etch Resist as a silicon dioxide masking agent is investigated, and the effects of additives and of a new developer, as well as those of ambient variations are outlined and their importance described.

A switch is designed which is capable of conducting 20,000 amperes and of holding off 100,000 volts after opening. This switch is to be employed in switching the energy from a 1 Mjoule superconducting coil. The switch element is a vacuum interrupter which is driven by a hydraulic actuation mechanism which can open ten pounds of contacts through a distance of 0.5 inch in 2 msec. Upon separation of the contacts, a 20,000 ampere arc is formed which must be extinguished by a commutation circuit. The commutation circuit consists of a pulse forming network which produces a 20,000 ampere bucking current which is applied for 2 microseconds. This 2 microsecond pulse continues to supply current to the energy storage coil once the vacuum interrupter arc has been extinguished, thus, acting to delay the rise of voltage generated by the coil and to permit the interrupter to partially recover its voltage stand-off capability. The use of a specific contact material and contact geometry to insure against the formation of anode hot spots and to permit a useful lifetime in excess of 50,000 cycles is described. The entire switch system including the vacuum interrupter, the hydraulic actuation mechanism and the commutator circuit has a total weight of 115 pounds.

Development and test of a 65KV Silicon Controlled Rectifier demonstrates the application of solid state devices and their inherent reliability in high power pulse modulator techniques. The design exploits the high voltage and high current capabilities of the SCR. Eighty devices in series yield a minimum holdoff voltage of 65KV; the test modulator switches pulse currents of 375 amperes although the SCRs have a 1000 ampere minimum peak pulse current capability. The 65KV SCR switch assembly employs a 'building block' concept utilizing ten, 6.5KV SCR switch assemblies. An electro-optical triggering technique eliminates trigger pulse transformers which require high voltage insulation between primary and secondary windings. These techniques are applicable to even higher voltage SCR switch assemblies. (Author)

An experimental model linear one kilowatt PEP all solid state HF amplifier and the factors leading to the development of the design approach used are described in this report. Sixty transistors were successfully combined over four octaves of band-width without individual tuning, or component selection. (Author)

This report includes the efforts expended on device refinement circuit design and development of a building for high power modulators utilizing the Type 291 flat packaged thyristor in a series stack configuration. An experimental breadboard modulator having a minimum holdoff of 10KV and switching a minimum of 375 amperes has been designed and the preliminary stages of construction are described. The preliminary design of a 65KV modulator using these building blocks as major components is described. (Author)

Data rates on communications systems in the very low frequency (VLF) and low frequency (LF) ranges are restricted by the limited bandwidth available on practical antennas. This report describes the experimental results obtained in employing reactive networks and a solid state transmitter to enhance the effective bandwidth of Low Frequency transmitting antennas. Field tests demonstrated the effectiveness of this technique by means of PSK transmissions and narrow-band FM voice transmissions over an LF link. Bandwidth enhancement greater than 4:1 was achieved.

Investigative techniques were developed and used to develop and evaluate glide slope techniques for problem site conditions. These techniques were used to serve as a basis for developing and evaluating modification of the 60 foot waveguide array and the reduced aperture array and for evaluation of the Redlich array. Evaluation of the antenna was carried out in terms of a digital modeling of this performance as measured by computed characteristics equivalent to those normally taken for commissioning i.e. level flight and structures. The level flight and structure were computed for conditions for which the antenna might be applied. (Author Modified Abstract)

The report describes the study and evaluation of a wide bandwidth space feed system for a phased array. The report describes the methods used to optimize the system parameters and evaluate the pattern performance. Results of the optimization and evaluation of a given configuration are presented. A comparison with a confocal paraboloid (nonoptimized) system is made. (Modified author abstract)