The effects of phase errors on optical SSB system performance

✍ Scribed by R. C. Lee; H. A. Abdul-Rashid; M. T. Al-Qdah; H. T. Chuah; M. B. Tayahi; S. Lanka

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 228 KB
• Volume: 48
• Category: Article
• ISSN: 0895-2477
• DOI: 10.1002/mop.21724

✦ Synopsis

the sensors are controlled by a general-purpose 8-bit 8051 microcontroller, which also controls the user interfaces and the operation of the EC device. The user interface consists on a keyboard and an alphanumeric liquid crystal display (LCD), and an infrared remote control. The scalability of the test cell is independent of the control system.

The control system software performs a program with three main menus: a. optical characterization: acquisition of the response times of the devices, and parameters described in Figure 3, regardless of the kind of EC; b. calibration: possibility of obtaining a look-up table of external and internal reachable illuminations; c. user application: selection of the internal illumination within the possible range achieved in menu b.

The results of the system operation for menu menu a matches those obtained in the preliminary characterization related in Figure 3. As an example, some results obtained with the first menu, directly from the application of the system and for the studied EC materials, are shown in Figure 3(b), while switching the device at constant illumination conditions.

Two main remarks can be derived from the graphs for these devices. The former one, the ability to measure and control the transmittance of the device, is achieved using photodiodes sensitive to the red part of the spectrum and a microcontroller system receiving sensing optical data and providing appropriate actions to manage the whole electrooptical system. The latter, no possibility of controlling the temperature, is achieved with these EC materials as yet, because the light changes in IR spectrum are still far from the operative ranges.