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Andrea Bevilacqua - One of the best experts on this subject based on the ideXlab platform.

  • Analysis and Design of a 17-GHz All- npn Push-Pull Class-C VCO
    IEEE Journal of Solid-State Circuits, 2020
    Co-Authors: Simone Veni, Pietro Andreani, Michele Caruso, Marc Tiebout, Andrea Bevilacqua
    Abstract:

    A push-pull oscillator topology that uses only one type of active device is proposed in this article. A Magnetic Transformer is leveraged to set positive feedback around a common-collector differential npn transistor pair, implementing the push-pull operation. This results in half the bias current for a given amplitude of oscillation, compared to more standard oscillator topologies. A thorough phase noise analysis of the circuit is carried out, emphasizing the crucial role of the Magnetic Transformer in the circuit operation and noise optimization. Proof-of-concept prototypes implemented in a 130-nm SiGe BiCMOS technology operate at 17 GHz and show a phase noise as low as −116 dBc/Hz at 1-MHz offset, while drawing 13.7 mA from the 3.3-V supply. The tuning range is 15%. While the circuit is demonstrated in SiGe BiCMOS technology, it lends itself equally well to implementations in other technologies where only one fast device is available, such as SiGe HBT, InP HBT, and GaN HEMT.

  • A 17 GHz All-npn Push-Pull Class-C VCO
    2019 IEEE BiCMOS and Compound semiconductor Integrated Circuits and Technology Symposium (BCICTS), 2019
    Co-Authors: Simone Veni, Michele Caruso, Marc Tiebout, Andrea Bevilacqua
    Abstract:

    A SiGe BiCMOS push-pull class-C VCO operating at 17 GHz and making use of only npn transistors is presented. A Magnetic Transformer is used to set positive feedback around a common-collector differential pair and implement the push-pull operation. This allows to halve the bias current for a given amplitude of oscillation, while using just one type of active devices. The oscillator features a phase noise as low as -116 dBc/Hz at 1 MHz offset, while drawing 13.7 mA from the 3.3 V supply. The tuning range is 15%.

  • Second-Order Equivalent Circuits for the Design of Doubly-Tuned Transformer Matching Networks
    IEEE Transactions on Circuits and Systems I: Regular Papers, 2018
    Co-Authors: Andrea Mazzanti, Andrea Bevilacqua
    Abstract:

    The doubly-tuned Magnetic Transformer, comprising coupled inductors shunted by capacitors, is today widely in use as interstage network and for impedance matching in silicon millimeter waves amplifiers. It provides several advantages, compared with simple LC resonators, but the design is made complex by the high order of the network, featuring multiple resonances, and by the large number of components to be selected. In this paper, a novel approach for the analysis and design of such a network is proposed. It is shown that the response can be very well approximated, in the neighborhood of each resonance frequency, by a second-order parallel or series RLC equivalent circuit. This yields simple equations for the impedance, the bandwidth, and the power loss, giving intuition into the network behavior, and greatly simplifying the design. Based on the results of the analysis, guidelines for the network optimization are proposed, targeting minimum power loss and a flat broadband response. Design examples of practical interest are presented: the component values estimated by hand calculation are in very good agreement with those provided by a numerical circuit optimizer.

  • Design of Low-Noise $K$ -Band SiGe Bipolar VCOs: Theory and Implementation
    IEEE Transactions on Circuits and Systems I: Regular Papers, 2015
    Co-Authors: Fabio Padovan, Marc Tiebout, Andrea Bevilacqua, Koen Mertens, Andrea Neviani
    Abstract:

    A study of $K$ -band SiGe bipolar VCOs is reported in this paper. The design challenges related to the operation in the $K$ -band and the use of a pure bipolar technology are discussed with particular emphasis to achieving low phase noise while using varactor diodes. Two different VCOs have been designed and fabricated. In the designs, the varactor is coupled to the active element by means of a Magnetic Transformer to avoid the use of tuning voltages exceeding the supply voltage. All the VCOs are operated in class-C. One of the designs features dynamic biasing to ensure robust start-up conditions. The VCOs feature a phase noise as low as $-$ 137 dBc/Hz at 10 MHz offset from the carrier. The VCOs show a state-of-the-art $FOM$ of $-$ 189 dBc/Hz, and an excellent $FOM_{T}$ of $-$ 193 dB/Hz.

Hwi-beom Shin - One of the best experts on this subject based on the ideXlab platform.

Xin-lan Li - One of the best experts on this subject based on the ideXlab platform.

Jong-sun Kim - One of the best experts on this subject based on the ideXlab platform.

Jae-sun Won - One of the best experts on this subject based on the ideXlab platform.