COMPUTER PROGRAMS: ELECTRONIC CIRCUIT DESIGN CRITERIA · Computer Programs: Electronic Circuit Design Criteria ON-AXIS POWER DENSITY IN THE FRESNEL AND FRAUNHOFER REGIONS OF LARGE-APERTURE

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COMPUTER PROGRAMS:ELECTRONIC CIRCUIT DESIGN CRITERIA

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Foreword

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Contents

Page

On-Axis Power Density in the Fresnel and Fraunhofer Regionsof Large-Aperture Rectangular and Circular Antennas 1

Faraday Rotation Computer Program 2Low-Noise Receiving System, Noise Temperature Calibrations 2Calibration of Microwave, Thermal Noise Standards 2Coupled Cavity Maser Noise Temperature 3Network Path Program 3System Attributes Program 4Resistor Calibration Program 4Program for Calibration of Standard Resistors 4Passive Network Program 5Minimum Phase Program 5Electronic Circuit Analysis Program (ECAP-AC) 6Realization Program 6Linear, Electronic Network Analysis Program 7Resistance Thermometer Callendar Equations • 7Simulation and Evaluation of a Convolutional Coded PCM

System with Sequential Decoding 8Computer Program to Determine the Effects of RF Filter

Second-and Third-Order Phase Errors and Non-Linear AmplitudeResponses for a Frequency-Division-Multiplexer System 8

Computer Program for the Simulation of a Multiplexer/DemultiplexerSystem for Non-Return-to-Zero or Biphase Data Transmission 9

Electric Power Analysis and List of Power Consuming-Equipment for Ships ... 9Ship Power System, Voltage-Dip Calculations 10Computer Program to Determine the Phase Error of a

Phase-Locked Loop Caused by Tape Recorder Flutter 10

Computer Programs:Electronic Circuit Design Criteria

ON-AXIS POWER DENSITY IN THE FRESNEL AND FRAUNHOFER REGIONS OFLARGE-APERTURE RECTANGULAR AND CIRCULAR ANTENNAS

Development of radio frequency transmitting sys-tems with high power transmitting tubes and highgain antennas has increased the possibility of bio-logical injury to personnel working in the vicinityof these emitters. The Bureau of Medicine andSurgery has established ten milliwatts per squarecentimeter (10 mW/cm2) as the safe continuousexposure level. The purpose of these programs is toprovide design engineers with power density datawhich may be used to predict radio frequencyradiation hazard (RAD HAZ) areas.

Given the transmitter power, the far field antennagain, the antenna dimensions, and the far fieldbeam width, Program DOD-OOOf3 calculates andprints out the near field gain, the near field beamwidth, and the on-axis power density in the Fresneland Fraunhofer regions of large aperture rectangularantennas.

Program DOD-00014 determines the aperture dis-tribution from the antenna parameters and calculatesthe on-axis power density in the Fresnel and Fraun-hofer regions of large aperture circular antennas.

The program reads and punches out the equipmentnomenclature and the equipment characteristics, in-cluding the diameter of the antenna, frequency, farfield antenna gain, and beam width. The far fielddistance is calculated. The distance at which thepower density is calculated is set at 10 feet initially.The defocusing factor is calculated. The powerdensity in the Fresnel region and the near fieldantenna gain and beam width are then calculatedand punched out. The distance is then increased by anincrement, and the program goes back to calculatethe new power density. This iteration loop continuesuntil the distance reaches 15,000 feet. For computingthe power density, the defocusing factor is set to 1when the distance exceeds the far field distance.

Language: FORTRAN IVMachine Requirements: IBM-7090

Source: Naval Ship Engineering Genter(DOD-00013,00014)

Circle 1 on Reader Service Card.

COMPUTER PROGRAMS: ELECTRONIC CIRCUIT DESIGN CRITERIA

FARADAY ROTATION COMPUTER PROGRAM

This program computes the Faraday rotation of asignal passing through a plasma in the presence of astatic magnetic field. An "exact" solution (the usualquasi-longitudinal approximation for the magneticfield is not used) provides the Faraday rotation foruniform stratified sections. The signal polarizationand ellipticity are computed for each step.

Language: FORTRAN V(60%), DATA (40%)Machine Requirements: UNIVAC-1108, EXEC-8

Source: Jet Propulsion Laboratory(NPO-11232)

Circle 2 on Reader Service Card,

LOW-NOISE RECEIVING SYSTEM, NOISE TEMPERATURE CALIBRATIONS

This is a program to calculate the system.noisetemperature of low-noise receiving systems by the"Y" factor method. In this method the power ratioat the system output is measured when the systeminput is connected alternatively between the antennaand an ambient termination. A statistical least squarestechnique is used to compute the best estimate of thepower ratio from a series of measurements.. Thesystem temperature is defined by the ambient termi-nation temperature, the receiver noise temperature,and the power ratio.

The program computes and tabulates the statisticalmeasurement dispersion errors and various systembias errors. In addition, various related system para-meters of interest, such as reflectometer matchmeasurements, are tabulated.

Language: FORTRAN IVMachine Requirements: IBM-7094/7044 DCS



CALIBRATION OF MICROWAVE, THERMAL NOISE STANDARDS

Calibrated microwave, thermal noise standardsusually consist of a matched element which isthermally isolated by a transmission line. This pro-gram calibrates these noise standards, accounting forarbitrary losses and temperature distributions alongthe transmission line. An iterative computing tech-nique is used to transfer the source terminationtemperature (T) at (X=0, i=l) to the output of thetransmission line at (X=£, i=n). The transmission lineloss distribution must first be determined by measur-ing the total loss (Lj) in db at various temperatures(Tj). A curve fit is determined from:

= —2LJ, db = Aj + A2Tt + A3Tj +•...

and the constants Aj, A2, ... (used as input data).The operational temperature distribution along thetransmission line entered as a table, Xj versus Tj,completes the required input data.

Language: FORTRAN IVMachine Requirements: IBM-7094/7044 DCS




COUPLED CAVITY MASER NOISE TEMPERATURE

This program has been designed for the analysisof the equivalent noise temperature of cascadednegative-resistarice maser amplifiers separated byisolators. The principal noise contributions in the am-plifying section are (1) amplified noise from thepreceding stages, (2) cavity losses and internal spintemperature contributions, and (3) noise from theoutput, including thermal noise and transmittednoise produced by the finite reverse attentuation ofisolators.

The effective noise temperature is determined bycalculating the noise contributions of the various

circuit elements, accounting for their gains, summing,and referring the net contributions to the amplifierinput. The output of the program includes curves forvarious gain, loss, reverse isolation, and maser in-version ratios.

Language: FORTRAN IIMachine Requirements: IBM-1620



NETWORK PATH PROGRAM

Network Path is a FORTRAN IV computer pro-gram to determine the Nth best minimum or maximumpath in a network. The program was developed froma paper by W. Hoffman and R. Pavley,/! Method forthe Solution of the Nth Best Path Problem. Theminimum tree concept as developed by E. F. Morreand G. B. Dantzig is employed to compute the bestpath. The minimum tree is then superimposed uponthe network to determine the Nth best path, using atheorem. Any path P from O to D, which is notminimal, is a deviation from a path Q from 0 to Dsuch that V(Q) < V(P). If P is minimal, theneither P is unique or P is a deviation from anotherminimal path.

The method relative to computer applicationconsiders first finding all the paths of minimalvalue, i.e., 3^ is computed. Next a calculation is madeof all deviations from the paths in ^l and they arearranged in numerical order according to the path

value which allows determination of $2- All de-viations from the paths in $2

are then computed,ordered, and merged with non-minimal deviationsfrom paths in <J>!, thus determining 4>3, etc. Only theNth best path values are stored at any stage of thecomputation; therefore, for large networks, the re-quired storage is essentially that which is needed tostore the network.

This program is written to handle up to 500 nodes,and the branch links cannot exceed 5000.

Language: FORTRANHMachine Requirements: IBM-360/65

Source: Rockwell International Corp.under contract to

Marshall Space Flight Center(MFS-18691)



SYSTEM ATTRIBUTES PROGRAM

This program provides a means of single channelverification for system checkout of amplifiers andfrequency-to-voltage converters on a group basis.The program calculates the average and precision ofanalog inputs on a single channel basis. It calculatesand stores an average count value for each selectedchannel based on 64 samples. This average value (basenumber) is compared to each data sample of theactual test. The sum of the differences and the sumof the squares of the differences are compared andstored as double precision words. Provisions are

included to delete bad channels, vary the samplesize, and select the format of the output.

Language: AssemblyMachine Requirements: DDP-116




RESISTOR CALIBRATION PROGRAM

This program computes the resistance, averageresistance, and precision of a stock resistor bycomparing it to a standard resistor.

The input consists of the ohms and serial numberof both the standard resistor and the tested resistor, acode number for the principal standard, and theresistance of the standard. This information is follow-ed by the voltage drops of the comparison standardand the test resistor.

Language: FORTRAN HMachine Requirements: IBM-360/Release 11




PROGRAM FOR CALIBRATION OF STANDARD RESISTORS

This program produces, for a standard resistor, atable of temperature vs resistance values from thefollowing formula:

where

IX'T1 ~

[1.0-A(T-25)+B(T-25)2]

Resistance, in ohms, at the given temperature= Temperature in °C= Resistance, in ohms, at 25° C (input)= Alpha coefficient in parts per million (input)= Beta coefficient in parts per million (input)

The table values are computed for a fixed temper-ature range of from 15° C to 35° C, in increments of0.05° C.

Language: FORTRAN HMachine Requirements: IBM-360, Version 11





PASSIVE NETWORK PROGRAM

This computer program calculates the input im-pedance and transfer function of an electrical networkcomposed of such components as capacitors, resistors,and inductors. The poles and zeros of the input im-pedance and network transfer function are computed.The network is described by the user with the aid of aproblem oriented input data sheet. The input im-pedance and transfer function are expressed as ra-tios of real polynomials P(s)/Q(s). The roots of P(s)and Q(s) are also expressed.

This program can be used for any R-L-C filter

network with a maximum of 40 components andtwenty current loops.


Source: The Boeing Companyunder contract to


Circle Won Reader Service Card.

MINIMUM PHASE PROGRAM

In designing control systems, it is necessary todesign a passive electrical network which satisfiesspecified gain and phase characteristics. It is assumedthat a passive network can be constructed whosecorresponding transfer function reflects stability ofthe network. If the minimum phase lag associatedwith a specified gain characteristic is less than adesired phase lag, then an actual electrical networkcan be constructed which will satisfy both gain andphase characteristics set forth by the engineer. TheMinimum Phase Program determines the minimumphase lag of passive electrical networks reflecting thedegree of stability of the transfer functions basicallyestablished by the gain characteristics determined bythe engineer in the program input. The phase lag isdetermined in the program as a function of frequencyfor a specified gain characteristic.

To describe gain characteristics, the programuser inputs a tabular array of gain versus frequencyand two slopes. The slopes are used to define thegain curve for frequencies before and after the

frequencies in the tabular defined region. The slopesare inputs. The integration technique employed is thetrapezoidal method, and the integration can beexpressed as a function of frequency. The limits ofintegration are computed from a fraction and multipleby each c frequency value. The fraction andmultiple integration limits are user input. The accu-racy of the technique depends primarily on theincrement used to form the base of each trapezoid.The user can divide the curve into three regions, eachwith its own frequency increment. The frequencyincrements are also user input.

Language: FORTRAN HMachine Requirements: IBM-360, Release 11

Source: The Boeing Companyunder contract to




ELECTRONIC CIRCUIT ANALYSIS PROGRAM (ECAP-AC)

This is a recent and different machine version ofthe IBM Electronic Circuit Analysis Program (knownas ECAP), an integrated system of programs designedto aid the electrical engineer in the design and analysisof electronic circuits. This system of programs canproduce DC, AC, and/or transient analyses of electri-cal networks from a description of the connections ofthe network (the circuit topology), a list of corre-sponding circuit element values, a selection of thetype of analysis desired, a description of the circuitexcitation, and a list of the outputs desired.

ECAP recognizes a set of standard electricalcircuit elements. Any electrical network that can beconstructed from any or all of the different elementsin the set can be analyzed by ECAP. There is almostno limit to the number of ways that the circuitelements can be arranged in the network. The set ofstandard circuit elements does not include electroniccomponents, but in many cases, these componentsare easily simulated by means of equivalent circuitsconstructed of standard elements. A number ofexamples are included in this manual that involve theuse of equivalent circuits.

ECAP can handle electrical networks that containas many as 20 nodes (not including ground j nodes)and 60 branches.

ECAP allows the circuit designer to economicallyand efficiently determine the performance of a

circuit during the various stages of its design, byUsing a computer rather than a "breadboard." In thisway, the designer can rapidly determine the variationsin circuit response that correspond to changes incircuit parameters. Studies can be made of circuitsthat contain costly components that may be difficultto obtain. Destructive excitation can be applied tothe circuit with no fear of destroying expensiveelectronic circuit elements. Worst case combinations,whicrrare hard, or practically impossible, to realize inthe laboratory, can be examined. Measurements thatmay be difficult to make, and time consuming toinstrument, can be made quite simply on the com-puter. Circuit connections can be changed rapidly.In many cases, ECAP can leave the designer with aclearer insight into the operation of the circuit thancould be obtained with a breadboard study, andoften at considerably less cost.

Language: FORTRAN IVMachine Requirements: CDC-6600

Source: General Dynamics Corp.under contract to

Lewis Research Center(LEW-10667)


REALIZATION PROGRAM

This program Is used to design frequency selectivenetworks when the network configurations or topol-ogy are given. The element values are perturbeduntil the final design (if possible) is achieved. Theprogram specifies the final design by prescribingelement values and/or a network function T(S).

It is assumed that the approximation problem hasbeen solved and that the coefficients of the desirednetwork functions are known.

The principal features of the program are itsabilities to accept arbitrary topologies, to "grow"new elements, and to converge rapidly.

It is possible to generate filters with prescribedloss from lossless filters, or to design bandpassamplifiers to accommodate transistors with prescribedsmall signal equivalent circuits. Also the frequencycharacteristics of networks can be altered by ad-justing certain elements. For example, passive or


active, linear phase filters can be transformed from.adesign originally having a Tchebysheff amplituderesponse.

Language: FORTRAN IVMachine Requirements: IBM-7090 or CDC-6400




LINEAR, ELECTRONIC NETWORK ANALYSIS PROGRAM

This program may be used to determine theLaplace transform of linear electronic networks. Itcan also be used for finding the corresponding polesand zeros as well as the frequency and/or time domainresponse of a network.

For input, the program requires a list of elements(described by their terminal node numbers, elementtypes, and element values) and functions (drivingpoint impedance, voltage transfer function, etc.).The program then calculates the coefficients of therequired network function, the poles and zeros,frequency response, and transient response to anarbitrary input.

Allowed element types are resistors, capacitors,inductors, non-ideal transformers, and voltage-con-trolled current sources in arbitrary configuration.Network size is limited to 12-15 nodes, 25-30elements.

Language: FORTRAN IVMachine Requirements: CDC-6400 or IBM-7094




RESISTANCE THERMOMETER CALLENDAR EQUATIONS

This program computes resistance values over aspecified temperature range for a resistance ther-mometer, using the Callendar equation. Input con-sists of: the thermometer's resistance at 100° Cand 0° C, the minimum and maximum temper-atures of the temperature range in either degreesCentigrade or Fahrenheit, the temperature incre-ment at which to compute resistance values, andtwo equation constants. If the requester desires not"

an option is available to input a third equationconstant. Output contains a table of temperaturevalues (degrees C or F) and resistance readings overthe temperature range.

Language: FORTRAN IVMachine Requirements: GE-635

Source: Kennedy Space Center— C;K-Se-1-042-2-)-

to input the thermometer's resistance at 100 C, Circle 15 on Reader Service Card.


SIMULATION AND EVALUATION OF A CONVOLUTIONAL CODED PCM SYSTEMWITH SEQUENTIAL DECODING

This program simulates and statistically evaluatesthe performance of a convolutional coded PCMcommunications system with sequential decoding.The communications channel is assumed to beperturbed by white, additive gaussian noise. Eachbinary symbol correlation received is A to D con-verted to, at, most, sixteen levels and stored in anarray. Each array is then sequentially decoded. Up to500 arrays or data frames may be decoded percomputer run, and overflow and error rate statisticsare then found and printed out.

The main program reads in system parameters,calculates parameters needed to encode and decode,

prints out system parameters, controls number offrames to be processed, serves as a calling program forsubroutines (and initializes subroutine Variables) need-ed for encoding and decoding, and calculates andprints out statistics for total number of framesprocessed.


Source: Goddard Space Flight Center(GSC-10653)


COMPUTER PROGRAM TO DETERMINE THE EFFECTS OF RF FILTERSECOND- AND THIRD-ORDER PHASE ERRORS AND NON-LINEAR

AMPLITUDE RESPONSES FOR A FREQUENCY-DIVISION-MULTIPLEX SYSTEM

A frequency-division-multiplex signal, when passedthrough a circuit consisting of an fm modulator, rffilter, discriminator (ideal), and band filters, or a non-linear amplifier, has distortion elements introduced.The circuit containing the rf filter introduces phasedistortion and the non-linear amplifier introducesamplitude distortion. In order to evaluate thesecircuits without the necessity of actually constructingthem and in order to evaluate the effects of varyingsignal bandwidths, spacing, and modulation, thiscomputer program determines the distortion intro-duced by these circuits into the signal. Input dataconsists of the upper and lower cut-off frequenciesand the peak deviation of the modulation for each ofup to ten bands; :the coefficients of each of up to four

terms in the numerator and the denominator of thetransfer function of the lowpass equivalent of the rfbandpass filter; the center frequency and the one-sided bandwidth of the rf filter; and the co-efficients of up to three terms in the transferfunction of the non-linear amplifier.

Language: FORTRAN IIMachine Requirements: RCA-601

Source: RCA Corp.under contract to

Goddard Space Flight Center(GSC-10586)



COMPUTER PROGRAM FOR THE SIMULATION OF A MULTIPLEXER/DEMULTIPLEXER SYSTEM FOR NON-RETURN-TO-ZERO OR

BIPHASE DATA TRANSMISSION

This program determines the effect on a signal of asimulated multiplexer/demultiplexer system consistingof a low-pass filter, a modulator, a bandpass filter forthe multiplexer, and a bandpass filter for the demul-tiplexer. The program accepts as input an arbitrarynon-return-to-zero or biphase data signal, the charac-teristics of the four filters, the modulating and de-modulating frequency, and a phase offset of thedemodulating frequency from the modulating fre-quency. The output from the program consists of aprintout of the amplitude and phase of each of theharmonics of the simulated signal at the output ofthe system, punched cards and a printout of the

amplitude values of the signal waveform as a functionof time, and a printout of the integrals of the fifth tothirtieth output signal pulses.





ELECTRIC POWER ANALYSIS AND LIST OFPOWER CONSUMING EQUIPMENT FOR SHIPS

This program generates listings of the ships'electric power consuming equipment and computeselectric loads required for a power analysis. Theprogram uses manually generated data and dataretrieved from a library of naval ship auxiliary powerconsuming equipment. For given quantities andfunctional load factors, the program produces a lineby line listing of all power consuming equipment andtheir electrical loads for various ship operatingconditions (at anchor, cruising, battle, etc.) andgroups the loads according to their categories (aux-iliary machinery loads, hotel loads; propulsion aux-iliary and steering loads, etc.). In addition, if indicated

by an input option, the program produces a line byline listing of all power consuming equipment andtheir power category numbers grouped.according totheir power categories.

The program requires a library of naval ship powerconsuming equipment.


Source: Naval Ship Engineering Center(DOD-00010)


10 COMPUTER PROGRAMS: ELECTRONIC CIRCUIT DESIGN CRITERIA

SHIP POWER SYSTEM VOLTAGE DIP CALCULATIONS

This program produces two calculations of voltagedip resulting from motor start-up occurring on agiven power generator switchboard. The first cal-culation is the voltage dip resulting from a motorbeing started on an unloaded generator. This cal-culation is done for each motor load on the generator.The second calculation is the voltage dip resultingfrom multiple motor starts on an unloaded generator.The queuing indicator, combined horsepower and

percent voltage dip are shown. Both calculations arerepeated for all input generator switchboard data.


Source: Naval Ship Engineering Center(DOD-00012)


COMPUTER PROGRAM TO DETERMINE THE PHASE ERROR OF APHASE-LOCKED LOOP CAUSED BY TAPE RECORDER FLUTTER

Phase-locked loops are frequently used to track theflutter introduced in a data system by a tape recorder.The loop tracks only part of the flutter; i.e., the lowfrequency flutter components. The high frequencycomponents, not tracked by the loop, create aresidual phase error. This computer program simulatesa second-order phase-locked loop and determines thephase error between an input subcarrier perturbed bytape recorder flutter and the output of the voltage-controlled oscillator. Static phase error resulting fromthe velocity drift of the tape recorder and random

components of the flutter are not taken into accountby the program.





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COMPUTER PROGRAMS: ELECTRONIC CIRCUIT DESIGN CRITERIA · Computer Programs: Electronic Circuit Design Criteria ON-AXIS POWER DENSITY IN THE FRESNEL AND FRAUNHOFER REGIONS OF LARGE-APERTURE