We developed a 60-GHz narrow-band module and a system-on-package (SoP) module in which an RF amplifier and a band-pass filter were integrated. We characterized the analog performance of modules by two-tone intermodulation measurements.
I. INTRODUCTIONThere seems to be no limit to the increases in speed and capacity in information communications. Trends in increasing transmission speeds herald the coming of an era in which wired communications using optical fibers and wireless communications will connect seamlessly at similarly increasing bit rates. As one of the millimeter wave bands for wireless transmission, the 60 GHz-band is of much interest since this is the band in which a massive amount of spectral space has been allocated worldwide for dense wireless local communications [1]. High natural atmospheric loss in the band makes the systems operate well in pico-cell zones. The 60-GHz radio-over-fiber (RoF) link would be a good candidate for future ultra-wide-bandwidth wireless access systems.In this paper, we present a 60-GHz narrow-band module and a system-on-package (SoP) module in which some functional components such as an RF amplifier and a bandpass filter (BPF) were integrated. We also show the analog performance of the modules by two-tone intermodulation measurements.
A built-in potential exists in the reflective liquid-crystal-on-silicon (LCoS) microdisplay cell due to the work-function difference between the aluminum and indium-tin-oxide electrodes. As a consequence, the flicker is generated unless the dc offset voltage is applied to compensate the built-in potential. In this paper, we present the experimental result that the dc offset voltage changes with time as the display is operated and the ions are generated in the liquid crystal (LC). To understand the experimental result, we simulate the ion motion in the LCoS cell by considering both the drift and diffusion. We discuss how the ion concentration in the LC affects the screening of the internal electric field in the bulk LC region and subsequently the built-in potential in the LCoS cell. We show that for an ion concentration higher than the value required to fully compensate the initial built-in potential, the polarity of the built-in potential is changed due to the high electric field near electrodes. By matching the experimental and simulation results, we predict how the ion concentration in the LC increases as a function of operation time.
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