Abstract: This paper proposes to use Routh-Hurwitz stability criterion for analysis and design of the operational amplifier stability; this can lead to explicit stability condition derivation for operational amplifier circuit parameters, and this is very effective to understand which parameter values should be increased or decreased for the operational amplifier stability. The proposed method has been verified by three amplifiers with theoretical analysis and SPICE simulations for three operational amplifier examples.
Abstract: Phase-shifting interferometry is widely used because it can measure phase with high accuracy. Changing optical path length with a PZT transducer and changing frequency of the optical source with a laser diode (LD) are two common methods to apply the desired phase shift between the arms in the interferometer. In any case, however, it is not easy to apply the desired shift accurately, and if not, measurement errors occur. In order to reduce the errors, the effect of the phase shift error has been analyzed numerically especially in the case with LD.
Abstract: In this paper, we propose an automatic design method that determines comparator topology and satisfies desired specification of the comparator by combining distributed genetic algorithm and HSPICE optimization function.In the comparator synthesis, new topology is created using known circuit topology information.After creating the topology, optimization of element values of the comparator is executed by distributed genetic algorithm and HSPICE optimization.As a target value example, specification of HA163S02 is used.Simulation results indicate that the proposed method can design the comparator despite the number of specifications and elements of circuit increase compared to the conventional methods.Furthermore, the performance of the automatic designed comparator is better than that of conventional comparators.
Abstract: This paper presents that the RC polyphase filer has characteristics as a complex analog Hilbert filter. Phase characteristics of the RC polyphase filter have the same as the Hilbert filter. Also its gain characteristics can be approximated as the Hilbert filter; as its order becomes higher, its gain characteristics become closer to the Hilbert filter. We have proved these for 1st to 4th RC polyphase filters, as well as in general n-th order case, and also confirmed with numerical simulations.
Abstract: Physical rehabilitation is required to support functional therapy in patients with restricted function in their body caused by cerebral, spinal, or muscular disorders. We sought to investigate the feasibility of medical and healthcare applications of the Kinect v2 motion capture devices and a head mount display in response to practical medical needs, including: (1) a Timed Up and Go test, and a walking rehabilitation support system; and (2) rehabilitation assistance using virtual reality feedback. The prototype systems demonstrate that the ICT-based rehabilitation equipment offers the objective and effective assessment of physical deficits in patients with conditions such as stroke or Parkinson's disease.
Abstract: In phase shifting interferometry phase shift is applied by various ways, but applying it with high accuracy, especially by LD current modulation, is not easy. In order to determine the accurate phase shift a new method has been proposed that the value of LD current corresponding to π/2 phase shift can be determined by phase shifting digital holography. The measured data of standard in surface shape measurement were used for calibration, and the obtained value was confirmed to cause noise reduction and improvement of holographic reconstructed images in digital holography.
Abstract: Phase difference image using phase-shifting digital holography is one of the prospective methods for non-contact shape measurement. For the application, filtering of the obtained image is needed to reduce the speckle noise. Conventional filter, e.g. moving average filter, causes loss of the shape information especially around the region with high steepness. To solve this problem novel filter has been developed that kept steepness of the shape in noise reduction. The filtered data were compared with conventionally filtering ones and the former was closer to the data observed by a laser measuring microscope.
Abstract: This paper describes analysis, simulation and experiment verification of high-frequency one-tone and two-tone low-distortion signal generation methods with an arbitrary waveform generator (AWG) for analog/mixed-signal IC testing. Our previously proposed phase switching method was limited to low-frequency signal generation, and it cannot be used directly for high-frequency signal generation. We propose here a method for generating a low-distortion high-frequency signal (i.e., the frequency close to the Nyquist frequency of the AWG) with an AWG, and show its theoretical analysis and simulation results. With this proposed method, 3rd order harmonics of the generated signal are suppressed simply by changing the AWG program (or waveform memory contents)—AWG nonlinearity identification is not required—and spurious components, generated far from the signal band, are relatively easy to remove using an analog filter.
Abstract: This paper presents an evaluation of double-rate Tomlinson-Harashima precoding in multi-valued PAM-N data transmission. In order to eliminate an intersymbol interference of interconnections in VLS system, Tomlinson-Harashima precoding (THP) is very useful for limiting the peak and average power of the transmitter. To expand the eye-opening at a receiver in multi-valued data transmission, we proposed a new equalization technique by using double-rate THP. In this paper, to evaluate the performance of the double-rate THP, we show the simulation results of the double-rate THP in various PAM-N data transmission on a micro-strip line.