Design and application of Digital Array Module automatic test system

Modern digital arrays radars (DAR) contain a large number of T/R modules. T/R module system is a critical part of digital array radar. It is necessary to test T/R module strictly before it is set up into the DAR. In practice, manual testing the T/R module with high performance is a complex and hard work, which for the difficulties of heavy test task and complex operations. In order to realize the automatic test of the active T/R modules, the advanced modern automatic test system (ATS) is built based on GPIB bus. The composition and the operation principle of the digital T/R module are introduced and the design of the hardware platform and software system is discussed. The high power measurement in transmitter and broadband data processing in receiver is researched. The timing control design is also introduced. Compared with manual test, the system is applied successfully shortens the test time to 1.5 hour from the manual 48 hours and the consistency of amplitude and phase between receiving channels is calculated automatically. The results showed the ATS can enhance the data processing speed and increase the testing efficiency of T/R module test.

The digital array radar (DAR) is a fully digitized phased array radar in which digital beam forming technique is used both in receive and transmit. A lot of simulations are made about the influence of amplitude-phase error on the antenna pattern, since amplitude-phase error of the antenna will severely affect the performances of the digital array radar. Based on the far-field external monitoring principle, the amplitude-phase error calibration method of the digital processing is studied, and the “in-the-field calibration” method, combining the reference data and the mid-field monitoring, is finally presented. Besides, the key techniques of the real-time DBF based on the FPGA processing platform are analyzed. The test results show that by using the method proposed, the high-precise calibration data can be obtained and the antenna beam after calibration can meet the digital array radar's requirements, and moreover the FPGA processing platform can realize the real-time multi-beam processing. It is a probe that the method combines the reference data and the mid-field monitoring, which is a simple, feasible and effective method for the digital array radar in the field calibration.

In this paper, a 10-channel digital array module(DAM) based on software radio theory model is designed for VHF-wave digital array radar. Up to now, DAM has fulfilled all project design requirements.

Rapid growth in the development and production of software-defined radios encourages some countries to manufacture their own radios by the use of new technology transfer agreements. Deployment of the automatic test equipment is a fundamental step of transfer of technology. As the automatic test equipments will be scattered throughout the world, the test systems should be designed accordingly to meet the new needs introduced. Since the cost of maintaining old systems is more expensive, using the existing automatic test systems and updating them according to the newly introduced needs is not an option. This fact encourages us to take a big step and design a completely new automatic test system. This paper introduces the new challenges encountered in the design, deployment and maintenance processes and describes the structure of the developed automatic test system in detail. The system described in this paper covers the typical automatic test equipment units like test and measurement devices, switching units, input/output components, loads and test software. However, the main focus of the paper is on the new test software introduced.

The dial gauge is used widely in the production line at present. The dial gauge has many types and huge quantity. At present, testing this type of instrument is mainly used manual observation method. By man-made factors, the testing efficiency and accuracy is low. In order to improve the test efficiency and accuracy, it is required to use the automatic test methods for dial gauge. Although the control algorithm of control system in automatic test system is simple, the control accuracy is high demanding. So the design of control systems is essential. This paper takes the dial gauge automatic test method for the object and studied on the control system in the automatic test system. It presents the design principles, methods in fully automatic test system and studied on the design of control systems, mechanical drive parts and the software architecture. Finally, through experimental results verify the test system design is reasonable. Practical application results show that the system is feasible, and the motion control system is high precision and higher intellectualized. It also has good application prospect, especially for some special environment which is not suitable for testing by human eye, this system shows its superiority.

In this paper some potential system and processing advantages of conformal cone shaped digital array radar have been investigated, in particular in relation to potential alternative approaches for angle estimation with respect to the traditional monopulse. First of all potential benefit in terms of reduction of the number of radiating elements is shown when a conical array is considered with respect to a traditional system formed by four planar arrays, if a coverage of 360° must be assured. Secondly, having in mind an innovative digital array system where the received signals are analog to digital converted at element level and the corresponding data are possibly transferred to a central elaboration unit, an alternative approach is investigated for angular estimation. In this paper we derive the theoretical expression of the Cramer Rao Lower Bound for elevation angle estimation using a cluster of beams; we compare the limit performance of the traditional approach for angle estimation based on Sum and Difference beams with the approach based on a crowded cluster of RX beams properly spaced. The approaches show approximately equivalent performance, making the second particularly interesting for those situations where monopulse is known to experience performance degradation, as low elevation angle estimation; in this particular case an example of cluster design is shown, where the direct signal from a low altitude target must compete with a specular multipath.

This paper describes two methods for testing high performance digital multichip modules (MCMs). The first technique provides a method for multiplexing automatic test system channels so that clock and data rates can be extended beyond the normal frequency limits of the Automatic Test Equipment (ATE). The multiplexing method has been successfully applied at rates up to 1.6 GHz using 200 MHz ATE. The second approach utilizes an electron beam probe system operating in the voltage contrast mode to measure electrical signals within the MCM. The e-beam probe can be used to supplement scan-based techniques for isolating faults. It can also be used for characterizing signal quality (rise-time, overshoot, crosstalk, reflections) and measurement of relative delays in high performance MCMs.

In order to make full use of the digital array radar (DAR), effective dwell scheduling must be implemented. According to the signal processing characteristics of DAR, an adaptive dwell scheduling algorithm is proposed. In this algorithm, time and energy vectors are introduced to implement pulse interleaving and the scheduling analysis, which breaks the limitations of strict interleaving conditions, and reduces the complexity of scheduling analysis compared with existing algorithms based on pulse interleaving technique. Meanwhile, the synthetic priority of the task and the validity of scheduling it are considered comprehensively. Simulation results demonstrate that the proposed algorithm can effectively improve the scheduling performance for DAR.

The purpose of this paper is to present a conceptual approach and to make practical recommendations on how to improve the current Automatic Test Equipment (ATE) testing and maintenance capabilities by utilizing the existing cloud computing model to build a globally linked ATE maintenance system. The basic tenet of the ATE community is to support a multi-tiered maintenance concept which, in general, is a three tiered system that is composed of organizational maintenance (O-level), intermediate maintenance (I-level), and depot maintenance (D-level) organizations. The goal of the ATE is to (1) quickly and accurately detect and isolate each fault, (2) provide software tools for analyzing historical data, and (3) gather, manage, and distribute accurate and reliable maintenance information for the failed Unit Under Test (UUT). The ATE system should provide services that will (1) maintain a repository of information that will improve fault detection and isolation, allow for off-platform assessments, document failures, and help quantify corrective actions, (2) reduce false UUT pulls, and (3) reduce repair time by prompting repair procedures. Furthermore, the ATE system should provide additional services that will help optimize the time to diagnose problems by using collected failure information and by recommending entry points into the Test Program Set (TPS) software. It should also present information to the ATE maintainer to aid in informed repair decisions which could be in the form of pilot debrief results, platform Built In Test (BIT) results, O-level test outcomes and corrective actions, and maintenance and usage history of the platform and UUT. So, based on this definition of ATE maintenance the use of cloud computing can be used to provide services to improve the overall ATE testing throughput which will result in bottom line improvements to ATE life cycle costs. By using cloud computing, which is defined to be “a model for enabling ubiquitous, convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications, and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction”, users can develop cloud computing models that will provide access to application software and databases that can be used to build a globally linked ATE maintenance system. This paper will discuss the essential characteristics of the cloud computing models and define the various flavors of cloud offerings available to designers today. This paper will also analyze the cloud computing model to arrive at a conceptual approach that can be used to enhance the current ATE Testing and Maintenance capabilities. Practical recommendations will be discussed on how to transform the current ATE Testing and Maintenance capabilities into the specific cloud computing model offerings in order to help configure a globally linked ATE maintenance system.

Fully digital phased array radars (PAR) enable rapid scanning of severe weather phenomena with high temporal and spatial resolution through adaptive beamforming and other advanced methods. An important challenge with such systems is the transferring, processing, and storing of the vast amount of data that can be produced, especially if element-level data are needed. Therefore, reduction of I/Q data size should be investigated when considering fully digital arrays for both scientific and operational needs. In this research, the effects I/Q linear quantization on polarimetric weather radar products has been examined. Among other effects, the results show that pulse compression effectively reduces quantization noise while maintaining the peak storm structure. As expected, negative quantization effects increase with lower signal-to-noise ratio (SNR).

Recent changes in the state-of-the-art in software development and test instrumentation has provided the Department of Defense with opportunities to reduce the cost of its automatic test systems (automatic test equipment and the software and information required to drive that equipment). In order to guide and enhance this evolution, the three Services (USN, USAF, USA) have developed an automatic test system research and development program consisting of three broad areas; automatic test system functional interface convergence, next generation test environment, and automatic test system modernization methods. This program, when funded, will provide the technology necessary to transition to the open architecture test systems of the future. The balance of this paper covers the eleven identified tasks under these broad areas, and how they form a coordinated, integrated basis for an improved acquisition strategy. >

An Entropy-based PSO for DAR task scheduling problem

In this paper, frequency broadband signal beamforming methods of digital array radar (DAR) are researched and broadband signal adaptive beamforming is realized through MVDR rule. Simulation and comparison show that blocked DFT beamforming method has advantage of little calculating quantity. For non-superposition of each block destroy the relativity of signal, blocked DFT make aberrance to pulse compression and take bad influence in succedent processing. Sliding-window DFT beamforming can achieve good performance of pulse compression, but it has large calculating quantity. Improved DFT beamforming method has the same calculating quantity with blocked DFT method, and it doesn't destroy the relativity of signal so that it can achieve good performance of pulse compression and in succedent processing. Improved DFT beamforming method is fit for used in engineering. The result of its application in DAR has been given.

A 1994 study identified that between 1980 and 1992, the services spent approximately $50 billion on automatic test systems (ATS). Controlling proliferation of ATS became the DoD's goal and led to policy which stated that DoD programs shall select ATS families to meet all ATS acquisition needs, and that introduction of unique ATS must be minimized. Beginning in 1996, DoD and industry together began work toward an open architecture for ATS by identifying the set of critical interfaces or key elements for which standards needed to be defined. Shortly afterward, the Joint Service Nxtest integrated program team began efforts toward evolving test technologies for insertion into DoD ATS. The original architecture has evolved into the DoD ATS framework which is published in the defense information technology standards registry. The joint service ATS framework working group, under the NxTest IPT, is accelerating efforts toward completing the framework. Cooperation between the services and industry has reached new levels with active participation in working groups and standards development bodies. In addition to demonstrating emerging test technologies, the agile rapid global combat support (ARGCS) advance concept technology demonstration project is helping to mature the ATS framework. When the ATS framework is completed and DoD has a truly open architecture for ATS, it is anticipated that DoD's ATS policy may shift from a hardware (families and COTS) perspective to a situation wherein any tester that fully implements the ATS framework must satisfy DoD's ATS-related goals, and the actual hardware used becomes less important.

The Automatic Test System (ATS) Executive Directorate (ED) is charged with developing objectives for the Department of Defense (DoD) ATS modernization. The DoD ATS Framework Working Group (FWG) was established by the ATS ED to create a Framework addressing these objectives. The FWG consists of two sub-groups; Management, that includes members from all of the DoD Services, and Technical. The Framework is made up of key elements and associated specifications and standards that form the open system architecture approach for DoD ATSs. In addition to creating and updating key element definitions, the FWG focuses on identifying commercial ATS related specifications that might satisfy the elements in the Framework. The standards specified in the DoD ATS Framework are documented in the DoD's Information Technology Standards Repository (DISR) and thereby become a mandatory requirement for all DoD ATS acquisitions. The Framework is also being specifically called out in DoD ATS requirements documents so that its standards are incorporated in future DoD ATS acquisitions, such as the Navy's eCASS. Although the ATS Framework was originally defined more than 10 years ago, it continues to evolve as test technology evolves. A function of the FWG is to continually assess the Framework and plan the development and demonstration of specifications and standards to satisfy ATS Framework requirements. The FWG is currently participating in the standards development process via standards organizations, consortia, and working groups. The FWG is evaluating these standards in terms of applicability to the twenty plus key elements defined in the Framework. The FWG is also continually evaluating new test and information technologies to further refine and add new key elements. When necessary, the FWG provides requirements and potential solutions to standards development teams so that the resulting standard will fit within the Framework. When these standards are published and proven to meet the requirements of a particular Framework element, the FWG makes recommendations to the DoD's ATS Management Board (AMB) regarding how these standards should be represented in the DISR. Standards which are mandated will be required by the acquisition process, and vendors' products acquired by the DoD must conform to them. This paper will provide a summary of the current activities and issues impacting the ATS Framework with a discussion of the near term plans of the FWG. It will provide status on the key elements that the FWG members are currently working on. These elements include the Adapter Functional and Parametric Data (AFP), Diagnostic Data (DIAD), Diagnostic Services (DIAS), Instrument Functional and Parametric Data (IFP), Master Conformance Index (MCI), Maintenance Test Data (MTD), Resource Adapter Interface (RAI), Run Time Services (RTS), Prognostics and Health Management (PHM), and Test Station Functional and Parametric Data (TSFP). The standards that satisfy or partially satisfy these key elements, and the current status of these standards are discussed. The paper also describes the purpose of, and the FWG's role in, several industry working groups; including LAN extensions for Instrumentation (LXI), Institute of Electrical and Electronics Engineers (IEEE) Standards Coordinating Committee 20 (SCC20), Interchangeable Virtual Instruments (IVI), and Synthetic Instruments Working Group (SIWG). Finally, current issues, such as how signal modeling is to be incorporated within the Framework, the relationship to the DoD's efforts with those of the UK Ministry of Defense (MoD), the use of the DISR mandated elements in upcoming DoD ATS acquisitions, and how O-level test capabilities could be incorporated in the Framework are discussed.