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[Author] Naoki TAKAYA(5hit)

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  • A 24 dB Gain 51–68 GHz Common Source Low Noise Amplifier Using Asymmetric-Layout Transistors

    Ning LI  Keigo BUNSEN  Naoki TAKAYAMA  Qinghong BU  Toshihide SUZUKI  Masaru SATO  Yoichi KAWANO  Tatsuya HIROSE  Kenichi OKADA  Akira MATSUZAWA  

     
    PAPER

      Vol:
    E95-A No:2
      Page(s):
    498-505

    At mm-wave frequency, the layout of CMOS transistors has a larger effect on the device performance than ever before in low frequency. In this work, the distance between the gate and drain contact (Dgd) has been enlarged to obtain a better maximum available gain (MAG). By using the asymmetric-layout transistor, a 0.6 dB MAG improvement is realized when Dgd changes from 60 nm to 200 nm. A four-stage common-source low noise amplifier is implemented in a 65 nm CMOS process. A measured peak power gain of 24 dB is achieved with a power dissipation of 30 mW from a 1.2-V power supply. An 18 dB variable gain is also realized by adjusting the bias voltage. The measured 3-dB bandwidth is about 17 GHz from 51 GHz to 68 GHz, and noise figure (NF) is from 4.0 dB to 7.6 dB.

  • Topology and Design Considerations of 60 GHz CMOS LNAs for Noise Performance Improving

    Ning LI  Qinghong BU  Kota MATSUSHITA  Naoki TAKAYAMA  Shogo ITO  Kenichi OKADA  Akira MATSUZAWA  

     
    PAPER-Microwaves, Millimeter-Waves

      Vol:
    E94-C No:12
      Page(s):
    1881-1888

    The noise performance of common source and cascode topology 60 GHz LNAs is analyzed and verified. The analysis result shows that the noise performance of the cascode topology is degraded at high frequency due to the inter-stage node capacitance. The analysis result is verified by experimental results. A three-stage LNA employing two noise-matched CS stages and a cascode stage is proposed. For comparison a conventional two-stage cascode LNA is also been studied with the measurement-based model. The measured results of the proposed LNA show that an input and output matching of less than -10 dB, a maximum gain of 9.7 dB and a noise figure (NF) of 3.2 dB are obtained with a power consumption of 30 mW from a 1.2-V supply voltage. Compared to the conventional cascode LNA, an improvement of 2.3-dB for NF and 1.9-dB for power gain are realized. Both the proposed and conventional LNAs are implemented in 65 nm CMOS process.

  • A Large-Capacity Service Control Node Architecture Using Multicasting Access to Decentralized Databases in the Advanced Intelligent Network

    Etsuo MASUDA  Takeshi MISHIMA  Naoki TAKAYA  Kohei NAKAI  Masanori HIRANO  

     
    PAPER-Issues

      Vol:
    E84-B No:10
      Page(s):
    2768-2780

    Focusing on a distributed control service-control-node (SCP) that houses a database (DB) distributed across multiple modules, this paper proposes an autonomous distributed SCP architecture using multicasting access to the distributed DB, and highlights its application areas. We assume as a basic condition that neither the network nor the other modules in the system are aware of the DB configuration. Based on this condition, we propose two basic methods: a unicast approach in which the DB management module that is selected at random by the network routes the DB access request to the module where the target data resides (Method A), and a multicast method in which DB access requests are broadcast to all modules (Method B). A quantitative evaluation is made of the number of required modules and required communications performance between modules which is determined by the capacity of the main memory and processing capacity of the processors. Based on the results, we conclude that Method B better exploits the advantages of module autonomous distribution technology within the limits that the economy of inter-module communication overhead is not impaired. Furthermore, in the event a module fails in Method B, a scheme is proposed in which the defective module is cut out of the multicast group, and multicasting continues. This could be implemented most effectively using a separate route under hardware control that is independent of the on-line communications route between modules.

  • A De-Embedding Method Using Different-Length Transmission Lines for mm-Wave CMOS Device Modeling

    Naoki TAKAYAMA  Kota MATSUSHITA  Shogo ITO  Ning LI  Keigo BUNSEN  Kenichi OKADA  Akira MATSUZAWA  

     
    PAPER

      Vol:
    E93-C No:6
      Page(s):
    812-819

    This paper proposes a de-embedding method for on-chip S-parameter measurements at mm-wave frequency. The proposed method uses only two transmission lines with different length. In the proposed method, a parasitic-component model extracted from two transmission lines can be used for de-embedding for other-type DUTs like transistor, capacitor, inductor, etc. The experimental results show that the error in characteristic impedance between the different-length transmission lines is less than 0.7% above 40 GHz. The extracted pad model is also shown.

  • Evaluation of a Multi-Line De-Embedding Technique up to 110 GHz for Millimeter-Wave CMOS Circuit Design

    Ning LI  Kota MATSUSHITA  Naoki TAKAYAMA  Shogo ITO  Kenichi OKADA  Akira MATSUZAWA  

     
    PAPER

      Vol:
    E93-A No:2
      Page(s):
    431-439

    An L-2L through-line de-embedding method has been verified up to millimeter wave frequency. The parasitics of the pad can be modeled from the L-2L through-line. Measurement results of the transmission lines and transistors can be de-embedded by subtracting the parasitic matrix of the pad. Therefore, the de-embedding patterns, which is used for modeling active and passive devices, decrease greatly and the chip area also decreases. A one-stage amplifier is firstly implemented for helping verifying the de-embedding results. After that a four-stage 60 GHz amplifier has been fabricated in CMOS 65 nm process. Experimental results show that the four-stage amplifier realizes an input matching better than -10.5 dB and an output matching better than -13 dB at 61 GHz. A small signal power gain of 16.4 dB and a 1 dB output compression point of 4.6 dBm are obtained with a DC current consumption of 128 mA from a 1.2 V power supply. The chip size is 1.5 mm 0.85 mm.