Richard J. Blackwell

Uncooled infrared sensors with digital focal plane array

Loral Infrared & Imaging Systems is developing low cost, high performance, uncooled infrared imaging products for both military and commercial applications. These products are based on the microbolometer technology, a silicon micromachined sensor which combines the wafer level silicon processing with a device structure capable of yielding excellent infrared imaging performance. Here, we report on the development of an uncooled sensor, the LTC500, which incorporates an all digital focal plane array and has a measured NETD of less than 70 mK. The focal plane array and the electronics within the LTC500 have been designed as an integrated unit to meet a broad range of end user applications by providing features such as nonuniformity correction, autogain and level, NTSC video, and digital outputs. The 327 X 245 element focal plane array has a 46.25 micrometers pixel pitch and an on focal plane array 14 bit to analog to digital converter (ADC). The ADC has a measured instantaneous dynamic range of more than 76 dB at a 6.1 MHz output data rate and 60 Hz frame rate. The focal plane array consumes less than 500 mW of power, of which less than 250 mW is used in the ADC. An additional 36 dB of digital coarse offset correction in front of the ADC on the focal plane array results in a total electronic dynamic range of 112 dB. The MRT of the LTC500 camera has been measured at less 0.2 C at fo.

Low-cost uncooled microbolometer imaging system for dual use

Loral Infrared & Imaging Systems is developing low cost, high performance uncooled infrared imaging products for both military and commercial applications. These products are based on the microbolometer technology, a silicon micromachined sensor which combines the wafer level silicon processing with a device structure capable of yielding NETD performance of better than 40 mK. To achieve a low cost sensor, Loral is proceeding with an integrated approach to the design and manufacturing processes associated with each major element of the uncooled sensor: focal plane array, electronics, optics and housings. Lorals 327 by 245 focal plane array has a 46.25 micrometer pixel pitch and incorporates a CMOS readout integrated circuit (ROIC). The ROIC has been designed to greatly simplify the external electronics, and features a single output which can operate at both 60 Hz (NTSC) and 50 Hz (PAL) video rates. The sensor electronics have been designed to meet a broad range of end user applications by providing both analog video and digital outputs with a large selection of user definable options and operating modes. To achieve low manufacturing costs across multiple end user applications, common optical interfaces, structural components, and manufacturing processes are being utilized. Sensor NETD is projected to be 40 mK normalized to f/1 and a 30 Hz frame rate. MRT is projected to be better than 0.1 degree Celsius at f0.

Uncooled VOx thermal imaging systems at BAE Systems

BAE Systems has advanced its 17 μm pitch LWIR 640 x 480 microbolometer technology with improvements in pixel performance and introduction of a new 17 μm pitch ROIC. We have fabricated, characterized, and demonstrated high-yielding 17 μm pitch FPAs using our new ROIC, and have successfully demonstrated them at the system level. This new technology builds on our 28 μm FPA production experience and implements our high-performance single-level microbolometer process at 17 μm pitch. We present initial results and imagery. These 17 μm FPAs have exceptional performance and provide the path to next generation microbolometer applications.

Recent developments in uncooled IR technology

Sanders IR Imaging Systems (IRIS), a Lockheed Martin Company, has made recent improvements in high performance uncooled IR focal plane arrays and systems. This paper provides performance results for three of these new FPAs and systems. First we discuss a new 320 X 240, 46 micrometer pitch FPA, which when put into a system with a transmission of 74%, will provide a system NETD of < 26 mK (F/0.8, 60 Hz). This FPA has a power of < 250 mW (which includes on-chip 14 bit analog to digital conversion), and virtually no crosstalk from saturation. Second, we discuss the first ever 640 X 480 element uncooled IR camera. This camera, which is based on a 28 micrometer pitch microbolometer staring FPA, produces a system sensitivity of < 150 mK, (F/1, 30 Hz) and has a Minimum Resolvable Temperature Difference of < 0.4 degrees Celsius at the Nyquist frequency. Finally, we have developed a new lightweight thermal weapons sight (TWS). Our TWS, which weighs < 3 lbs. (with battery) and operates over the -37 degrees Celsius to +49 degrees Celsius temperature range, has demonstrated a boresight retention of < 0.2 mrad after 1000s of rounds were fired.

17 μm microbolometer FPA technology at BAE Systems

BAE Systems has continued to advance its 17 μm pitch LWIR 640 x 480 microbolometer technology with improvements in pixel performance and initial production for several emerging products. In addition, we have developed short time constant variants of our standard pixel design to support applications requiring short thermal time constants. The technology is expanding to include a 1024x768 format megapixel FPA to support higher resolution applications.

Developments in uncooled IR technology at BAE SYSTEMS

Uncooled microbolometer thermal imaging sensor technology has begun to successfully address military, government and commercial applications in the real world. BAE SYSTEMS, located in Lexington MA, has been involved in the design and development of uncooled IR technology since the early 1980s. Our current MicroIRTM products are based on vanadium oxide (VOx) microbolometers. Thousands of uncooled microbolometer thermal imaging sensors are now being produced and sold annually. A the same time, applied research and development on the technology continues to improve the basic products and make them suitable for new applications. In this paper we report on the status and improvements achieved in the MicroIRTM product line, based on 320 X 240 element and 160 X 120 element FPAs with 46 μm pixel pitch. Other near term MicroIRTM products include 320 X 240 and 640 X 480 FPAs with 28 micrometers pixel pitch and measured sensitivities below 50 mK. In the systems area we discuss development and testing of a Light Thermal Weapon Sight (LTWS) for the U.S. Army, being developed by BAE SYSTEMS in partnership with Thales, based upon our uncooled MicroIRTM focal plane arrays (FPA) and systems. The LTWS prototypes were based upon our Standard Imaging Module SIM200, which employs our LAM2C, 320 X 240 element, microbolometer FPA. Finally we discuss the 480 X 640 element FPA and its application to the Heavy Thermal Weapon Sight application.

Advances in uncooled technology at BAE SYSTEMS

BAE SYSTEMS has made tremendous progress in uncooled technology and systems in the last year. In this paper we present performance results and imagery from our latest 640x480 and 320x240 small pixel focal plane arrays. Both were produced using submicron lithography and have achieved our lowest NETDs to date. Testing of the 320x240 devices has shown TNETDs of 30mK at F/1. Video imagery from our 640 x 480 uncooled camera installed in a POINTER Unattended Aerial Vehicle is also shown. In addition, we introduce our newest commercial imaging camera core, the SCC500 and show its vastly improved characteristics. Lastly, plans for future advancements are outlined.

Small pixel uncooled imaging FPAs and applications

BAE Systems continues to make dramatic progress in uncooled microbolometer sensors and applications. This paper will review the latest advancements in microbolometer technology at BAE Systems, including the development status of 17 micrometer pixel pitch detectors and imaging modules which are entering production and will be finding their way into BAE Systems products and applications. Benefits include increased die per wafer and potential benefits to SWAP for many applications. Applications include thermal weapons sights, thermal imaging modules for remote weapon stations, vehicle situational awareness sensors and mast/pole mounted sensors.

Recent technology advancements and applications of advanced uncooled imagers

BAE Systems has made dramatic progress in uncooled microbolometer sensors and applications in the last year. The topics covered in this paper are: results and video from our latest 640x480 FPAs with sensitivities of better than 50 mK (f/1) and overviews of systems for military and commercial applications.

Lockheed Martin's 640x480 uncooled microbolometer camera

Lockheed Martin is developing the first ever 640 X 480 uncooled microbolometer camera. This camera, designated the LTC650, has a new 28 micrometers pitch 640 X 480 microbolometer focal plane array and electronics which operate at a 30 Hz frame rate. The electronics are based on previous successful 320 X 240 camera electronics which use low power, high performance DSP and FPGA technology. A DSP based software solution provides flexibility to answer the challenge of change and varied customer needs while meeting the low cost, low power, and low real estate requirements of portable, hand held applications. Test data for the first camera are presented.