A low-cost uncooled infrared detector array and its camera electronics

Akçören, Dinçay
This thesis presents the development of integrated readout electronics for diode type microbolometers and development of external camera electronics for microbolometers. The developed readout electronics are fabricated with its integrated 160x120 resolution FPA (Focal Plane Array) in the XFAB SOI-CMOS 1.0 μm process. The pixels in the FPA have 70 μm pixel pitch, and they are sensitive in the 8–12 μm band of the infrared spectrum. Each pixel has 4 serially connected diodes, and diode turn on voltage changes as the temperature of the suspended and thermally isolated pixel increases due to the absorbed infrared power. Suspension of the pixels is obtained with a post-CMOS MEMS etching process, but this process requires no critical litography and/or deposition steps. This dramatically reduces the detector process cost, which makes this microbolometer FPA suitable for ultra low-cost applications such as automobile, security, and commercial applications. The readout electronics of the FPA include digital blocks such as timing and programming blocks as well as analog blocks such as a differential trans-conductance amplifier, a switched capacitor integrator, a sampleand- hold, and current DACs. This new readout design has reduced number of pins to simplify the external electronics and allows wafer-level vacuum packaging compared to the 128x128 FPA developed in a previous study at METU with the same approach. Both of these features further decrease the cost. Two kinds of external camera electronics are developed for two SOI type microbolometers. The first one is for the 128x128 SOI microbolometer previously designed in METU. The developed external camera electronics have 1.5mVrms noise, which is much less than the microbolometer noise. The overall system has an average NETD of 465 mK and a peak NETD of 320mK. The second developed external camera electronics are for the 160x120 SOI microbolometers that developed in the scope of this thesis. The developed external camera electronics has 0.55mVrms noise which is much less than the bolometer noise which is 5mVrms. The overall system has an average NETD of 820 mK and a peak NETD of 350 mK. Each of these external camera electronics include a custom designed PCB, an FPGA board with appropiate configurion and a software working on a PC. The custom designed PCB holds the external components for the microbolometer, an FPGA takes and processes the bolometer data and it sends to a PC, and a PC processes these data and forms a streaming video. These two external camera electronics allow to obtain human images verifying that the developed microbolometers can be used for security and automotive applications.


High performance readout electronics for uncooled infrared detector arrays
Yıldırım, Ömer Özgür; Akın, Tayfun; Department of Electrical and Electronics Engineering (2006)
This thesis reports the development of high performance readout electronics for resistive microbolometer detector arrays that are used for uncooled infrared imaging. Three different readout chips are designed and fabricated by using a standard 0.6 m CMOS process. Fabricated chips include a conventional capacitive transimpedance amplifier (CTIA) type readout circuit, a novel readout circuit with dynamic resistance nonuniformity compensation capability, and a new improved version of the CTIA circuit. The fabr...
Millimeter wave gunn diode oscillators
Lüy, Ülkü; Toker, Canan; Department of Electrical and Electronics Engineering (2007)
This thesis presents the design and implementation of a millimeter-wave Gunn diode oscillator operating at 35 GHz (Ka (R) 26.5-40 GHz Band). The aim of the study is to produce a high frequency, high power signal from a negative resistance device situated in a waveguide cavity by applying a direct current bias. First the physics of Gunn diodes is studied and the requirements that Gunn diode operates within the negative differential resistance region is obtained. Then the best design configuration is selected...
Development of electrochemical etch-stop techniques for integrated MEMS sensors
Yaşınok, Gözde Ceren; Akın, Tayfun; Department of Electrical and Electronics Engineering (2006)
This thesis presents the development of electrochemical etch-stop techniques (ECES) to achieve high precision 3-dimensional integrated MEMS sensors with wet anisotropic etching by applying proper voltages to various regions in silicon. The anisotropic etchant is selected as tetra methyl ammonium hydroxide, TMAH, considering its high silicon etch rate, selectivity towards SiO2, and CMOS compatibility, especially during front-side etching of the chip/wafer. A number of parameters affecting the etching are inv...
A monolithic phased array using rf mems technology
Topallı, Kağan; Aydın Çivi, Hatice Özlem; Department of Electrical and Electronics Engineering (2007)
This thesis presents a novel monolithic phased array implemented using the RF MEMS technology. The structure, which is designed at 15 GHz, consists of four linearly placed microstrip patch antennas, 3-bit distributed RF MEMS low-loss phase shifters, and a corporate feed network. The RF MEMS phase shifter employed in the system consists of three sections with a total of 28 unit cells, and it occupies an area of 22.4 mm 2.1 mm. The performance of the phase shifters is improved using high-Q metal-air-metal ca...
Analysis and design of passive microwave and optical devices using the multimode interference technique
Sunay, Ahmet Sertaç; Birand, Mehmet Tuncay; Department of Electrical and Electronics Engineering (2005)
The Multimode Interference (MMI) mechanism is a powerful toool used in the analysis and design of a certain class of optical, microwave and millimeter wave devices. The principles of the MMI method and the self-imaging principle is described. Using this method, NXM MMI couplers, MMI splitter/combiners are analyzed. Computer simulations for illustrating the "Multimode Interference Mechanism" are carried out. The MMI approach is used to analyze overmoded 'rectangular metallic' and 'dielectric slab' type of wa...
Citation Formats
D. Akçören, “A low-cost uncooled infrared detector array and its camera electronics,” M.S. - Master of Science, Middle East Technical University, 2011.