Advantest Laboratories Ltd.

Sendai-shi, Japan

Advantest Laboratories Ltd.

Sendai-shi, Japan
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Mai-Khanh N.N.,University of Tokyo | Ikeno R.,University of Tokyo | Yamaguchi T.J.,Advantest Laboratories Ltd. | Iizuka T.,University of Tokyo | Asada K.,University of Tokyo
2016 IEEE International Conference on Electronics, Circuits and Systems, ICECS 2016 | Year: 2016

The paper presents an experimental demonstration of fine-resolution stochastic analog-to-digital converter. The effective LSB resolution and number of comparators versus linear region neighbouring the trip point are introduced by measurement data. The approach is to use a fully differential comparator scheme to suppress input common-mode noise. A layout strategy of manually placing and routing is proposed to reduce systematic variation and to achieve Gaussian random offset distribution. Four testing chips are fabricated in a 180-nm CMOS process and then measured by a low-noise DC measurement setup for fully differential analog inputs. The result shows that a Gaussian offset distribution can be achieved with a reasonable number of comparators. Compared with conventional approach, the effective LSB resolution is 10 times smaller but with less than 10 times of the number of comparators. © 2016 IEEE.

Sato T.,Advantest Laboratories Ltd. | Okayasu J.,Advantest Laboratories Ltd. | Takikawa M.,Advantest Laboratories Ltd. | Suzuki T.-K.,Japan Advanced Institute of Science and Technology
IEEE Electron Device Letters | Year: 2013

We investigated AlGaN-GaN metal-insulator-semiconductor high-electron-mobility transistors (MIS-HEMTs) with high-permittivity (high-k) oxynitride TaOxNy gate dielectric (k ∼24) obtained by sputtering deposition. The MIS-HEMTs show excellent pulsed current-voltage characteristics, small off-leakage currents (10-10A/mm), high on/off current ratios (>10-10), and favorable threshold voltage stabilities. From comparisons with MIS-HEMTs with TaOx gate dielectric, we conclude that N incorporation in gate dielectric can suppress current collapse and deep-level states. © 1980-2012 IEEE.

Niitsu K.,Gunma University | Sakurai M.,Konica Minolta | Harigai N.,Gunma University | Yamaguchi T.J.,Gunma University | And 2 more authors.
IEEE Journal of Solid-State Circuits | Year: 2012

This paper describes a reference-clock-free, high- time-resolution on-chip timing jitter measurement circuit using a self-referenced clock and a cascaded time difference amplifier (TDA) with duty-cycle compensation. A self-referenced clock with multiples of the clock period removes the necessity for a reference clock. In addition, a cascaded TDA with duty-cycle compensation improves the time resolution while maintaining the operational speed. Test chips were designed and fabricated using 65 nm and 40 nm CMOS technologies. The areas occupied by the circuits are 1350 μm2 (with TDA, 65 nm), 490 μm2 (without TDA, 65 nm), 470 μm2 (with TDA, 40 nm), and 112 μm2 (without TDA, 40 nm). Time resolutions of 31 fs (with TDA) and 2.8 ps (without TDA) were achieved. The proposed new architecture provides all-digital timing jitter measurement with fine-time-resolution measurement capability, without requiring a reference clock. © 2012 IEEE.

Masuda S.,Advantest Laboratories Ltd. | Seki A.,Advantest Laboratories Ltd. | Shiota K.,Advantest Laboratories Ltd. | Masuda Y.,Hachinohe Institute of Technology
Journal of Lightwave Technology | Year: 2011

We present a simple 2 × 2 port MachZehnder (MZ) interferometer-type photonic switch with multimode interference (MMI) 3-dB couplers using epitaxially grown lanthanum-modified lead zirconate titanate (PLZT) films. The MZ-type MMI PLZT photonic switch with 8-μm-gap coplanar electrodes exhibits a low half-wave voltage of 4.8 V with an extinction ratio of 28 dB for a 2 mm active-region length. An optical insertion loss for the presented switch is measured as 2-3 dB that excluded the coupling losses in lensed fibers for a 6.5-mm-long device. © 2010 IEEE.

Masuda S.,Advantest Laboratories Ltd. | Seki A.,Advantest Laboratories Ltd. | Shiota K.,Advantest Laboratories Ltd. | Hara H.,Advantest Laboratories Ltd. | Masuda Y.,Hachinohe Institute of Technology
Journal of Applied Physics | Year: 2011

We investigate the electro-optic properties and high-frequency relative dielectric constants of epitaxially grown lanthanum-modified lead zirconate titanate (PLZT) and polycrystalline barium titanate (BaTiO3) films in a high-frequency range of up to 40 GHz for designing a high-speed ferroelectric thin-film modulator. We also demonstrate a ferroelectric thin-film Mach-Zehnder-type waveguide modulator using the epitaxially grown PLZT film. The use of a composite structure with a low dielectric coefficient substrate and a buffer layer enabled of a ferroelectric thin-film waveguide modulator with 40-Gb/s operation. © 2011 American Institute of Physics.

Masuda S.,Advantest Laboratories Ltd. | Seki A.,Advantest Laboratories Ltd. | Masuda Y.,Hachinohe Institute of Technology
Applied Physics Letters | Year: 2010

We describe here how we have improved the crystal qualities and controlled the crystal phase of the lanthanum-modified lead zirconate titanate (PLZT) film without changing the composition ratio using an oxygen-pressure crystallization process. A PLZT film deposited on a SrTiO3 substrate with the largest electro-optic (EO) coefficient of 498 pm/V has been achieved by controlling the crystal phase of the film. Additionally, a fatigue-free lead zirconate titanate (PZT) capacitor with platinum electrodes has been realized by reducing the oxygen vacancies in the films. © 2010 American Institute of Physics.

Koyama S.,Advantest Laboratories Ltd. | Onishi M.,Advantest Laboratories Ltd. | Kimishima M.,Advantest Laboratories Ltd.
2014 Asia-Pacific Microwave Conference Proceedings, APMC 2014 | Year: 2014

This paper describes a 10 MHz -12 GHz low distortion high speed single pole 4 throw (SP4T) switch for RF Automated Test Equipment (ATE) using a newly developed GaN HEMT fabrication process. The switch is fabricated with the Schottky GaN HEMT process which feature very low gate leakage current with tantalum oxynitride (TaON) passivation films to improve distortion performances at low frequency. The switch has high input 3rd order intercept point (IP3) of more than 52 dBm across a frequency range of 10 MHz to 12 GHz and fast settling time of less than 10 μs to within 0.01 dB. An on-chip decode logic with TTL level input for the state control is also integrated. Copyright 2014 IEICE.

Tsushima T.,Advantest Laboratories Ltd. | Takeuchi H.,Advantest | Kimishima M.,Advantest Laboratories Ltd.
2015 IEEE International Symposium on Radio-Frequency Integration Technology, RFIT 2015 - Proceedings | Year: 2015

This paper describes a 10 MHz - 6 GHz high power high linearity 35 dB digital step attenuator monolithic microwave integrated circuit (MMIC) for radio frequency automated test equipment (RF ATE) systems. The digital step attenuator MMIC is fabricated using a novel Schottky gallium nitride high electron mobility transistor (GaN HEMT) process that is characterized in very low gate leakage current with tantalum oxy nitride (TaON) passivation technology. Owing to the characteristic of the developed GaN HEMT, circuit topologies for improving large signal performance in wideband from lower frequency can be employed, and the MMIC shows input 1 dB compression point (IP1dB) of more than +40 dBm and input 3rd order intercept point (IIP3) of more than +55 dBm. © 2015 IEEE.

Yamaguchi T.J.,Advantest Laboratories Ltd. | Yamaguchi T.J.,University of Tokyo | Komatsu S.,University of Tokyo | Abbas M.,University of Tokyo | And 3 more authors.
Digest of Papers - IEEE Radio Frequency Integrated Circuits Symposium | Year: 2012

This paper proposes a new flash time-to-digital converter (TDC) design, which incorporates deterministic, variable delay into the decision elements. These are implemented with cross-coupled NAND standard cells of variable transistor widths. Both experiment and simulation are used to validate this new design, which provides variable time-difference ranges by controlling the input slew rate. It is also possible to use the proposed flash TDC as a soft macro. © 2012 IEEE.

Tandon J.S.,University of Tokyo | Tandon J.S.,Microsemi | Yamaguchi T.J.,University of Tokyo | Yamaguchi T.J.,Advantest Laboratories Ltd. | And 2 more authors.
Proceedings - IEEE International Symposium on Circuits and Systems | Year: 2014

This paper presents a subsampling two-step coarse-fine stochastic A/D converter for on-chip measurement of high speed signals. Using equivalent time sampling techniques, we achieve an effective sampling rate of over 230 GS/s measurements for a 23.0023 MHz sine wave, and over 5.8 TS/s for an on-chip 2921.0115 MHz 7-bit PRBS while using a clock rate of 23 MHz. Our ADC achieves an SNR of 55.3 dB and SNDR of 40.6 dB without calibration for the sine wave measurement. We improve on previous work by reducing the number of comparators required per stochastic group while extending dynamic range to cover a rail-to-rail input signal. © 2014 IEEE.

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