CCG615_SOW.docx

Statement of Work Inductive Voltage Divider Attenuation System Project Number: CCGXYZ 6 Mar 2012

Statement of Work 1312 Attenuation Measurement System IVD Flexible Drivers and System Augmentation Project Number: CCG615 – 12 May 2015

1.0 Technical Problem.

The Air Force Primary Standards Laboratory (AFPSL) recently took delivery of the Tegam 1312 Attenuation Measurement System with Calibration Coordination Group (CCG) Project 615. This attenuation system is based upon a binary Inductive Voltage Divider (IVD) in the system as a highly precise attenuation standard. This attenuation system has initially shown itself to be robust and reliable. As a follow-on project to CCG 615, there are other hardware capabilities inherent in the IVD attenuation system that the AF desires to quantify, and also to incorporate some new value-added features into the software application.

2.0 Objectives. Several objectives to this project are listed below. Software must be operationally validated and verified, and should be intuitive for operators, but need not be fully commercially compliant. The Air Force shall be granted unlimited, unrestricted data rights to the software / source code from the publisher or developer. This shall include but is not limited to: use, duplication, modification, distribution, and disposition of the software application source code. Contractor shall provide a two-year warranty which shall consist of 120 hours of follow-on technical support over the full warranty period following delivery, installation, and training.

2.1 This objective develops flexible support of any Original Equipment Manufacturer (OEM) automated step attenuator. This requires restructuring the application to support programmable attenuators from other OEMs. The general approach and necessary elements to accomplish this objective are listed below:

2.1.1 Restructure the application to allow selection of more than one “driver” for the Device Under Test (DUT) attenuator. The restructured application will be limited to supporting DUTs that communicate through a command/response interface that uses a paradigm similar to “send(‘command’); read(‘response’)” using a string or character ‘command’ and ‘response’ format. This encompasses full capability to support GPIB, LXI, RS-232, USB devices that enumerate as serial port devices. The design of the application envisions ‘command’ and ‘response’ being strings that can be built and deciphered using the C# language. This SOW explicitly excludes adding support for devices requiring the loading of and interfacing with a “driver” DLL or other loadable library presenting function calls or methods to interface with the DUT. This scope is limited to support of DUTs that can be set to the correct attenuation using a fixed number of “send” type commands without having to evaluate any “read” commands.

2.1.1.1 Restructure application to pass test RF frequency into DUT driver calls.

2.1.1.2 Specifically develop capability for automated testing of Rohde & Schwarz RSC series attenuators as DUTs.

2.1.1.3 Create a flexible lookup of DUT commands and data formats, allowing for additional DUT’s from any OEM to be added later.

2.1.1.4 Restructure application to support multiple means of communication with DUT (IEEE 488, LXI, USB, serial, etc., all through NI MAX VISA).

2.1.1.5 Test and debug application onsite at the AFPSL on two separate occasions.

2.1.2 Update manual to cover and describe the use of new flexible DUT driver interface.

2.2 This objective restructures the application to optimize noise reduction by including capability to perform independent numbers of outer and inner measurement loops based upon both frequency and attenuation. This should also minimize calibration uncertainties and test times.

2.3 This objective adds frequencies and attenuation points for system hardware certification. The full frequency range of the system hardware will be characterized such that traceable attenuation calibrations may be performed at any desired frequency throughout the full frequency range (30 MHz to 1.2 GHz) of the system hardware.

2.3.1 Calibration of the Air Force Agilent 8496G check standard step attenuator at NPL shall be accomplished with test reports at 30 MHz, 50 MHz, 200 MHz, 1 GHz, 1.2 GHz, and at attenuation levels down to and including 110 dB. If NPL offers no service at a particular frequency/attenuation pair, a test by NPL at a different pair agreed to by AFMETCAL or a test by a different lab agreed to by AFMETCAL shall be an acceptable alternative.

2.3.2 Testing and reporting of capability is limited to the existing system hardware. It is anticipated that the existing system hardware will produce uncertainty estimates that exceed the original system specifications of 0.001 dB + 0.001/10 dB if used at attenuations in excess of 100 dB or frequencies in excess of 1 GHz. This scope requires no hardware modifications and provides no guaranteed system performance for attenuations in excess of 100 dB and/or frequencies in excess of 1 GHz.

2.3.3 Plan tests, create test specification tables (files), develop uncertainty budgets, analyze test results, and produce reports at 200 MHz and 1.2 GHz, additional to the current 30 MHz, 50 MHz, and 1 GHz cardinal points.

2.3.4 Report the feasibility of extending frequency coverage throughout the full system range from 30 MHz to 1.2 GHz and attenuations beyond 100 dB.

2.3.5 Some clarification is to be noted regarding the requirements of para 2.3 and its subparagraphs. (a) This objective shall develop application ability to test a DUT at an arbitrary frequency and attenuation levels within the overall constraints of the system hardware, which are being further determined, and report the results in the same format as the existing system. (b) The advanced features of the RSC attenuator will not necessarily be addressed by the modified driver system. So (for example) if special features are required for testing the RSC attenuators, they would have to be set manually or edited into the initialization commands of the test executive controlling the testing of the RSC attenuators themselves, but would not be included in the 1312 test executive. (c) Project requirements do not include the ability to "program" test data back into the RSC adjustment tables. (R&S may have software for doing that, and the test data would need to be reformatted, maybe using EXCEL. But this would be an initiative outside the scope of this project.) (d) At frequencies higher than 1.2 GHz, a loss of amplifier gain is predicted which is expected to result in unsatisfactory results.

2.4 This objective quantitatively evaluates increasing the dynamic range of the calibrated attenuation values.

2.4.1 Report the uncertainty budget for extending dynamic range to 110, 120, and 130 dB, including associated concerns and impacts.

2.5 This objective adds capability to compute and report the real-time dynamic uncertainties at every frequency and attenuation level of test, based upon actual calibration conditions at time of test. This is respective to on-the-fly real-time conditions and measurements and report their true value for each frequency and attenuation value calibrated. This will be a combination of Type B information derived from design calculations and performance testing (IVD error and system linearity), and of Type A data derived from the standard deviation of the outer loop variables.

2.5.1 Add tables for inputting the Type B parameters from defined tests.

2.5.2 Add tracking of loop statistics for R_DUT.

2.5.3 Add logging of relevant statistical data.

2.5.4 Add reporting of resulting Type A and B components of each test result in the log and report file.

3.0 Expected Products. There are several expected products as deliverables and outcomes from this project:

3.1 An expected deliverable is a restructured application with all of the previous capabilities plus the following: flexible driver support with ability to support multiple automated step attenuators as described in 2.1 and its subparagraphs with the simple addition of a driver developed by AFMETCAL or the AFPSL later; full capability to support Rohde & Schwarz RSC series programmable step attenuators; flexible means of communication protocols with any DUT through NI MAX VISA.

3.2 An expected deliverable is a restructured application to allow for an independent number of outer and inner loops based upon frequency and attenuation. This will minimize calibration uncertainties due to noise and repeatability as well as optimizing for minimum test times.

3.3 An expected deliverable is a calibration with report from NPL or other source acceptable to AFMETCAL of the Air Force Agilent 8496G check standard step attenuator with reports of calibration at 30 MHz, 50 MHz, 200 MHz, 1 GHz, 1.2GHz, and attenuation levels down to and including 110 dB.

3.4 An expected deliverable is certification of the full 30 MHz to 1.2 GHz frequency range as well as attenuation ranges of the system hardware. This includes development of test tables and uncertainty budgets at 200 MHz and 1.2 GHz, additional to the current 30 MHz, 50 MHz, and 1 GHz.

3.5 An expected deliverable is a written report evaluating the possible extension of extending the frequency coverage throughout the full system range to 30 MHz to 1.2 GHz. The report shall include uncertainty budgets and analysis of test results. The general frequency range of the system from 30 MHz to 1.2 GHz shall be addressed; with specific analysis at 200 MHz, 1.195 GHz, and 1.2 GHz.

3.6 An expected deliverable is a written report evaluating the possible extension of the dynamic range of the system to and including 110 dB, 120 dB, and 130 dB with uncertainty budgets and other potential impacts.

3.7 An expected deliverable is a restructured application which will dynamically compute and report real-time uncertainties at every frequency and attenuation level of test based upon real-time calibration conditions which will truly indicate the AFPSL attenuation uncertainties.

3.8 An expected deliverable is an updated manual describing use of flexible new DUT driver interface and other enhancements.

3.9 An expected deliverable is training of AFMETCAL and AFPSL personnel.

4.0 Expected Benefits. There are several expected benefits to this project:

4.1 An expected benefit is a restructuring of the application allowing for programmatic control of step attenuators from other OEMs. This will allow the AFPSL to calibrate step attenuators regardless of the OEM. Flexible drivers can be developed with the AFMETCAL and AFPSL software developers. Particularly full capability for calibrating Rohde RSC series step attenuators will be obtained. Support for different communication protocols will also be included. This should provide for long term sustainment of the IVD attenuation system.

4.2 An expected benefit is a restructured application to allow for inputting separate exit criteria for inner and outer loop for each test line. This will permit selection of minimum loop executions and statistical criteria that are most appropriate for each test line. This will optimize noise reduction and support running of tests with minimum uncertainty wihile minimizing test times.

4.3 An expected benefit is NPL calibration of the Air Force Agilent 8496G check standard step attenuator with reports of calibration at 30 MHz, 50 MHz, 200 MHz, 1 GHz, 1.2GHz, and attenuation levels down and including 110 dB. The additional data will help establish repeatability of the 8496G step attenuator as a reliable artifact for traceability purposes, as well as provide for additional frequencies and attenuation levels in certifying the full frequency range of the IVD attenuation system hardware.

4.4 An expected benefit is certification of the full 30 MHz to 1.2 GHz frequency range as well as attenuation ranges of the system hardware. This shall include development of test tables and uncertainty budgets at 200 MHz and 1.2 GHz to facilitate calibration of any frequency and attenuation level desired within the frequency range noted above. Attenuation levels and dynamic range of the system are being evaluated as possible expansions beyond the current total attenuation of 100 dB.

4.5 An expected benefit is a written report evaluating the possible extension of extending the frequency coverage throughout the full system range from 30 MHz to 1.2 GHz. The expected benefit of this is to show unqualified use of the IVD attenuation for any frequency within this range. The uncertainty budgets and analysis of test results to be included in the report are expected to show full capability of the system and any exceptions to the use of the system within the full frequency range of the system. Specific analysis at 200 MHz, 1.195 GHz, and 1.2 GHz combined with the other frequency points already established (30 MHz, 50 MHz, and 1 GHz) is expected to adequately cover the traceability concerns to certify the IVD attenuation system full band.

4.6 An expected benefit is a written report evaluating the possible extension of the dynamic range of the system to and including 110, 120, and 130 dB. Uncertainty budgets and other potential impacts shall be included and is expected to answer the questions of how low of attenuation levels can the IVD attenuation system support. Increased uncertainties are expected as the dynamic range is expanded and quantification of these uncertainties as a function of increased dynamic range will be valuable information for the AF in utilizing the full capabilities of the IVD attenuation system. Note that this scope provides for calibration of an artifact to and including 110 dB of attenuation (NPL calibrated 8496G). Actual testing at 120 dB and 130 dB may be performed but artifacts of suitable uncertainty may not be available.

4.7 An expected benefit is a restructured application which computes and reports dynamic real-time uncertainties at every frequency and attenuation level of test. These dynamic uncertainties shall be based upon real-time calibration conditions and will provide for conformance to the current guidelines in expressing uncertainty of measurements and accurate reporting of true IVD attenuation system capabilities.

4.8 An expected benefit is an updated manual describing the use of the flexible new DUT driver interface and other enhancements. This will provide technical documentation for operation and use of the IVD attenuation system.

4.9 An expected benefit is training of AFMETCAL and AFPSL personnel will be beneficial in imparting information to use and maintain the IVD attenuation system.

5.0 Major Tasks. This follow-on project will only be one phase. The major tasks included within this phase are highlighted below in narrative and timeline form. Regarding the timelines, at each breakpoint in accomplishing a major task, a teleconference or site visit (at AFPSL or vendor) shall occur in discussion of the work required and the expected deliverables at the end of that major task. Performance of the work agreed upon for that major task (in telecon and contract modification) performed by contractor shall be discussed. A meeting or teleconference shall occur between AFMETCAL and contractor to review work performed regarding that major task, and discussion / concurrence on a course of next action shall be agreed in contract modification before proceeding with next major task. Some of the major tasks may occur simultaneously. In such case each of the major tasks will be evaluated independently upon their own merits in accordance with the other requirements of this paragraph and the SOW. If determination is made to continue the major taskings and to what extent, a Memorandum of Agreement (MOA) will be coordinated with the contractor summarizing the decisions arrived at during the teleconference or meeting, and AFMETCAL will issue a contract modification that formally provides guidance to the contractor of the activities and work authorized in the next steps major taskings.

5.1 Design, code, test, and deliver application capable of testing flexible DUTs specifically including Rohde RSC attenuators and conforming to design requirements of 2.1 herein and deliverable 3.1.

5.2 Design, code, test, and deliver application providing line-item customization of exit criteria for both inner IVD loop and outer Attenuation loop (deliverable 3.2).

5.3 Send 8496G artifact to NPL for calibration at 30 MHz, 50 MHz, 200 MHz, 1 GHz, 1.2 GHz and all attenuation steps down to and including 110 dB.

5.4 Measure system repeatability at six frequencies listed below, at attenuations from 0 through 130 dB in 10 dB steps. TEGAM will plan tests, AFMETCAL will execute, and TEGAM will analyze and report. This includes one visit to AFMETCAL. This data is for error budgeting. Frequencies of measurement for system repeatability include 30 MHz, 50 MHz, 200 MHz, 1 GHz, 1.195 GHz, 1.2 GHz.

5.5 Test system against artifact at 30 MHz, 50 MHz, 200 MHz, 1 GHz, 1.2GHz, and attenuation levels down to and including 110 dB. Prepare and deliver report of results and comparison with proposed error budget from deliverables 4.5 and 4.6, updated error budget, and conclusion regarding system capability (deliverable 3.4). This assumes testing is planned by TEGAM and conducted by AFMETCAL, and includes one visit by TEGAM to AFMETCAL.

5.6 Prepare proposed error budget at all six frequencies, at attenuations from 0 through 130 dB in 10 dB steps. TEGAM will report and discuss with AFMETCAL (deliverables 3.5 and 3.6) and includes one visit to AFMETCAL.

5.7 Design, hold review, redesign, code, test/evaluate, redesign, code, test, and deliver application supporting dynamic uncertainty estimation based on criteria in 2.5 and deliverable 3.7

5.8 Documentation and Training (deliverables 3.8 and 3.9)

6.0 Milestone Charts. (Updated milestone charts will be provided at time of award):

Q4 Jul-Sep Q1 Oct-Dec Q2 Jan-Mar Q3 Apr-Jun Q4 Jul-Sep Q1 Oct-Dec

7.0 Reviews, Meetings and Reporting Requirements.

7.1 Quarterly Progress Reports and Final Report shall be provided. Quarterly reports shall include at a minimum: the project title and number, reporting period, report generation date, a summary of technical progress, any milestone problem (technical, financial, schedule), and plans for the following quarter.

7.2 Draft copies of required documentation shall be provided at least one week prior to any scheduled reviews/acceptance.

7.3 All documentation may be in contractor’s format.