Introduction

The Digital Signal Processing Line Replacement Unit (DLRU) is one of the sub-systems in an Aerostat, which provides resources for radar signal processing, data capturing, data recording with other radar control functions.

The Case Study highlights Mistral’s expertise in the architecture and design of a custom hybrid system that supports two industry standard bus architectures VME and VPX, to meet the requirements of input/output signals, communication links, processing capability and high-speed data transfer capability.

The Customer

A leading Defense Lab selected Mistral to design, build and integrate a system capable of functioning as a DSP Line Replaceable Unit.

The Requirement

The customer’s requirement was to design and integrate a solution that addressed their overall functional and performance criteria while adhering to SWaP (Size, Weight, and Power), the longevity, product lifecycle management and subsystem integration norms.
The key requirements for the proposed solution included:

• Mechanical design of the Digital Signal Processing Line Replacement Unit with structural and thermal analysis
  • The DLRU unit had to be housed in a sheltered space on an Aerostat
  • The unit had to be designed to comply with Environmental Stress Screening Test as per MIL-HDBK2164, Safety of Flight Test (SOFT) as per MIL-STD-810E and EMI/EMC test as per MIL-STD-461E
• Design and Fabrication of the hybrid backplane (VPX and VME)
• Custom Design and Fabrication of three VPX based Processor Boards and four VME based channel receiver boards
• Generation of Wiring Charts, ICD (Inter Connection Document) and cable harness diagrams as per the ICD

The unit had to be equipped with:

• FPGA based processing system
• High Speed Fiber Optical Module capable of communication using sFPDP protocol
• High speed Gigabit Ethernet Ports for inter communication
• RF input and output through SMA connectors
• RS232 Serial Ports from for debugging
• RS422 level based line sports from processor cards to front panel for communication and debugging
• I/O Debug ports
• Provision of Redundant Power
• Power Supplies to cater for the entire unit. Circuit breakers and protection circuitry to be provided to prevent damage to the electronics housed in the unit
• LED’s to indicate the health of the power supplies.

The Solution

Mistral is a professional design services company with extensive experience in embedded hardware and software development for Mil-Aero applications. This capability, in conjunction with partnerships with leading embedded solution providers like Curtiss Wright Controls Defense Solutions, enabled Mistral to provide a complete solution to meet the customer expectations.

Mistral developed an air cooled Digital Signal Processing Line Replacement Unit, comprising of the following components: 

• Custom Hybrid Backplane supporting VME and VPX technologies
• Three VPX based processing boards based on Xilinx Virtex-5 FPGA
• Four Quad Channel VME based Receiver Modules
• Single channel sFPDP high Speed Fiber Optical Module mounted on VPX board capable of communication using sFPDP protocol
• VPX based Data Recorder card
• 7 Gigabit Ethernet Ports on VPX based processor cards through Quadrax connectors
• Xilinx Virtex-6 FPGA based VME I/O board
• Six RS232 Serial Ports on the front panel for debugging
• 156 RS422 level based linesports on front panel
• Debug ports on the three VPX based processing cards
• Input power Supply range 16-32V
• 16 SMAconnectors (4 Per Quad channel receiverfor RF input or output)
• Custom designed Front Panel Board, which consists of all the Circular connectorsfor I/Os, Quadrax circularconnectors for Gigabit Ethernet, LED’s, Power switch and reset switch
• Two Fans housed on the rear of the unit for efficient heat transfer which can be controlled through software
• Necessary EMI filters, fuse voltage, current monitor and Sense circuit for automatic output voltage regulation.

Read full case study to know about System backplane design, Hardware – Software Design and Integration.