3D Time-of-flight distance measurement with custom - Universität ...

II
4. Power budget and resolution limits................................................................. 85
4.1 Optical power budget............................................................................... 85
4.2 Noise limitation of range accuracy........................................................... 90
5. Demodulation pixels in CMOS/CCD................................................................. 99
5.1 Pixel concepts ....................................................................................... 102
5.1.1 Multitap lock-in CCD ..................................................................... 102
5.1.2 4-tap lock-in pixel.......................................................................... 104
5.1.3 1-tap lock-in pixel.......................................................................... 109
5.1.4 Summary: Geometry and speed performance.............................. 113
5.2 Characterization of 1-tap pixel performance.......................................... 116
5.2.1 Charge to voltage conversion ....................................................... 116
5.2.2 Measurement setup, expectations and predictions ...................... 120
5.2.3 Determination of optimal control voltages..................................... 130
5.2.4 Influence of optical power and integration time @ 20 MHz .......... 134
5.2.5 Demodulation contrast versus frequency and wavelength ........... 137
5.2.6 Phase accuracy measurements ................................................... 139
5.2.7 Noise performance and dynamic range........................................ 142
5.2.8 Comparison of measured distance accuracy with theory ............. 143
5.2.9 Summary....................................................................................... 145
5.3 Outlook: Two-photosite demodulation pixel .......................................... 147