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[Keyword] PDL(6hit)

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  • PAPR Reduction Method for Digital Predistortion Linearizer Compensating for Frequency Dependent IMD Components

    Yasunori SUZUKI  Junya OHKAWARA  Shoichi NARAHASHI  

     
    PAPER-Microwaves, Millimeter-Waves

      Vol:
    E101-C No:2
      Page(s):
    118-125

    This paper proposes a method for reducing the peak-to-average power ratio (PAPR) at the output signal of a digital predistortion linearizer (DPDL) that compensates for frequency dependent intermodulation distortion (IMD) components. The proposed method controls the amplitude and phase values of the frequency components corresponding to the transmission bandwidth of the output signal. A DPDL employing the proposed method simultaneously provides IMD component cancellation of out-of-band components and PAPR reduction at the output signal. This paper identifies the amplitude and phase conditions to minimize the PAPR. Experimental results based on a 2-GHz band 1-W class power amplifier show that the proposed method improves the drain efficiency of the power amplifier when degradation is allowed in the error vector magnitude. To the best knowledge of the authors, this is the first PAPR reduction method for DPDL that reduces the PAPR while simultaneously compensating for IMD components.

  • Low-Power Driving Technique for 1-Pixel Display Using an External Capacitor Open Access

    Hiroyuki MANABE  Munekazu DATE  Hideaki TAKADA  Hiroshi INAMURA  

     
    INVITED PAPER

      Vol:
    E98-C No:11
      Page(s):
    1015-1022

    Liquid crystal displays (LCDs) are suitable as elements underlying wearable and ubiquitous computing thanks to their low power consumption. A technique that uses less power to drive 1-pixel LCDs is proposed. It harvests the charges on the LCD and stores them in an external capacitor for reuse when the polarity changes. A simulation shows that the charge reduction depends on the ratio of the capacitance of the external capacitor to that of the LCD and can reach 50%. An experiment on a prototype demonstrates an almost 30% reduction with large 1-pixel LCDs. With a small 10 × 10mm2 LCD, the overhead of the micro-controller matches the reduction so no improvement could be measured. Though the technique requires longer time for polarity reversal, we confirm that it does not significantly degrade visual quality.

  • PDL Suppression on Long-Period Fiber Gratings by Azimuthally Isotropic Exposure

    Yuu ISHII  Kensuke SHIMA  Satoshi OKUDE  Kenji NISHIDE  Akira WADA  

     
    PAPER

      Vol:
    E85-C No:4
      Page(s):
    934-939

    We investigate a method to suppress the polarization-dependent loss (PDL) of long-period fiber gratings (LPFGs). We study the origins of the PDL and propose an azimuthally isotropic UV exposure to suppress the UV-induced birefringence and to realize low-PDL LPFGs. By using this technique and a low birefringent fiber together, the PDL of LPFGs can be reduced to a sufficiently low level required in high performance communication systems. Moreover, the validity of our theoretical modeling is confirmed by the experimental results.

  • Bistable Switching in PDLC Film with a Ferroelectric Alignment Layer

    Masako INOMATA  Masahiro NAKAGAWA  

     
    PAPER

      Vol:
    E79-C No:8
      Page(s):
    1047-1057

    In this work is first presented that a PDLC film with a ferroelectric alignment layer realizes a bistable switching in similar to the surface-stabilised ferroelectric liquid crystal display devices. Such a bistability is found to critically depend on the squareness parameter of the ferroelectric layer as well as such material properties of the dispersed nematics as the elastic and the dielectric constants. It is also found that there exists an appropriate elastic constant to improve the optical transmittance. The dependence of the distribution of the radii of the nematic droplets on the electro-optic bistability is also investigated in detail by means of the numerical computations assuming a fractal distribution. The fundamental electro-optic properties of the presently, proposed PDLC cells imply the advantage beyond the conventional PDLC without any ferroelectric alignment layer.

  • Unified Process Flow Management System for ULSI Semiconductor Manufacturing

    Etsuo FUKUDA  

     
    PAPER-CIM/CAM

      Vol:
    E79-C No:3
      Page(s):
    282-289

    A unified process flow management system (UPFMS) that combines a CIM system, process/device simulator, CAD system, and manufacturing line schedular has been developed. This new system uses a new language called PDL to describe the process flow as common information for all systems. The UPFMS consists of the flow edit section, the flow inspection section, and several types of interface programs to make it suitable for use with other systems. The process flow data described using the PDL in the UPFMS provides data for controlling lots in CIM system. If modification of the process flow data in the CIM system is required, the process flow data is returned to the UPFMS and modified with inspection using a knowledge data base. Then, the error-free process flow data is sent back to the CIM system for Processes after flow inspection. Moreover, the UPFMS, with the new language PDL, generates recipe data for the equipment using an interface program, and recipe data is input to several types of equipment. Furthermore, the PDL process flow data can also be used as input data for the manufacturing line scheduler using another interface program. Mask and layout data in a CAD system can be exchanged among process/device simulators by using the UPFMS, and thus two-dimensional device characteristics. Spice paramenters can be also to be created. The UPFMS combines with CIM system, process/device simulator, CAD system, and the manufacturing line scheduler using common information, PDL. The process flow data created in the UPFMS can be used to control all systems from the simulation to CIM system as common data.

  • Experience of Solving Example Problem for Software Process Modeling

    Hajimu IIDA  Yoshihiro OKADA  Katsuro INOUE  Koji TORII  

     
    LETTER-Software Systems

      Vol:
    E76-D No:2
      Page(s):
    302-306

    Marc Kellner proposed an example problem intending to compare modeling and describing techniques of software process. In this paper, we will describe our approach to understanding and describing the problem, from a process/product relation view, and synchronization/concurrent view. Also, we will show that a description of the problem is translated for execution and its correctness is validated.