1,224 research outputs found

    SiGe-based broadband and high suppression frequency doubler ICs for wireless communications

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    制度:新 ; 報告番号:甲3419号 ; 学位の種類:博士(工学) ; 授与年月日:2011/9/15 ; 早大学位記番号:新574

    Advanced space communications architecture study. Volume 2: Technical report

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    The technical feasibility and economic viability of satellite system architectures that are suitable for customer premise service (CPS) communications are investigated. System evaluation is performed at 30/20 GHz (Ka-band); however, the system architectures examined are equally applicable to 14/11 GHz (Ku-band). Emphasis is placed on systems that permit low-cost user terminals. Frequency division multiple access (FDMA) is used on the uplink, with typically 10,000 simultaneous accesses per satellite, each of 64 kbps. Bulk demodulators onboard the satellite, in combination with a baseband multiplexer, convert the many narrowband uplink signals into a small number of wideband data streams for downlink transmission. Single-hop network interconnectivity is accomplished via downlink scanning beams. Each satellite is estimated to weigh 5600 lb and consume 6850W of power; the corresponding payload totals are 1000 lb and 5000 W. Nonrecurring satellite cost is estimated at 110million,withthefirstunitcostat110 million, with the first-unit cost at 113 million. In large quantities, the user terminal cost estimate is $25,000. For an assumed traffic profile, the required system revenue has been computed as a function of the internal rate of return (IRR) on invested capital. The equivalent user charge per-minute of 64-kbps channel service has also been determined

    CMOS design of chaotic oscillators using state variables: a monolithic Chua's circuit

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    This paper presents design considerations for monolithic implementation of piecewise-linear (PWL) dynamic systems in CMOS technology. Starting from a review of available CMOS circuit primitives and their respective merits and drawbacks, the paper proposes a synthesis approach for PWL dynamic systems, based on state-variable methods, and identifies the associated analog operators. The GmC approach, combining quasi-linear VCCS's, PWL VCCS's, and capacitors is then explored regarding the implementation of these operators. CMOS basic building blocks for the realization of the quasi-linear VCCS's and PWL VCCS's are presented and applied to design a Chua's circuit IC. The influence of GmC parasitics on the performance of dynamic PWL systems is illustrated through this example. Measured chaotic attractors from a Chua's circuit prototype are given. The prototype has been fabricated in a 2.4- mu m double-poly n-well CMOS technology, and occupies 0.35 mm/sup 2/, with a power consumption of 1.6 mW for a +or-2.5-V symmetric supply. Measurements show bifurcation toward a double-scroll Chua's attractor by changing a bias current

    A delay spread cancelling waveform characterizer for RF power amplifiers

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    A two channel 65 nm CMOS RF-waveform characterizer is presented that enables multi-harmonic Adaptive Matching Networks (AMN) or Adaptive Digital Pre-Distortion (ADPD) in RF-power amplifiers. The characterizer measures the DC component and the first 3 harmonics of RF signals by applying a DFT to 8 (ideally) equally spaced quasi-DC output voltages. Conventionally in these types of systems accuracy is limited by sample timing accuracies, which in our case are mainly due to delay cell mismatch. We introduce a novel way to cancel delay cell mismatch, that significantly increases measurement accuracy at the cost of only a small power and area increase. The RF-waveform characterizer achieves 6.8-bit measurement linearity together with a (clock feedthrough limited) 24 dB SFDR. The measured power consumption for our proof-of-principle demonstrator is 18.6 mW at a maximum input signal frequency of 1.1 GHz under continuous operation

    LBR-2 Earth stations for the ACTS program

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    The Low Burst Rate-2 (LBR-2) earth station being developed for NASA's Advanced Communications Technology Satellite (ACTS) is described. The LBR-2 is one of two earth station types that operate through the satellite's baseband processor. The LBR-2 is a small earth terminal (VSAT)-like earth station that is easily sited on a user's premises, and provides up to 1.792 megabits per second (MBPS) of voice, video, and data communications. Addressed here is the design of the antenna, the rf subsystems, the digital processing equipment, and the user interface equipment

    RF to Millimeter-wave Linear Power Amplifiers in Nanoscale CMOS SOI Technology

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    The low manufacturing cost, integration capability with baseband and digital circuits, and high operating frequency of nanoscale CMOS technologies have propelled their applications into RF and microwave systems. Implementing fully-integrated RF to millimeter-wave (mm-wave) CMOS power amplifiers (PAs), nevertheless, remains challenging due to the low breakdown voltages of CMOS transistors and the loss from on-chip matching networks. These limitations have reduced the design space of CMOS power amplifiers to narrow-band, low linearity metrics often with insufficient gain, output power, and efficiency. A new topology for implementing power amplifiers based on stacking of CMOS SOI transistors is proposed. The input RF power is coupled to the transistors using on-chip transformers, while the gate terminal of teach transistor is dynamically biased from the output node. The output voltages of the stacked transistors are added constructively to increase the total output voltage swing and output power. Moreover, the stack configuration increases the optimum load impedance of the PA to values close to 50 ohm, leading to power, efficiency and bandwidth enhancements. Practical design issues such as limitation in the number of stacked transistors, gate oxide breakdown, stability, effect of parasitic capacitances on the performance of the PA and large chip areas have also been addressed. Fully-integrated RF to mm-wave frequency CMOS SOI PAs are successfully implemented and measured using the proposed topology

    Switching mode power amplifier for bluetooth applications

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    Modern fully integrated transceivers architectures, require circuits with low area, low cost, low power, and high efficiency. A key block in modern transceivers is the power amplifier, which is deeply studied in this thesis. First, we study the implementation of a classical Class-A amplifier, describing the basic operation of an RF power amplifier, and analysing the influence of the real models of the reactive components in its operation. Secondly, the Class-E amplifier is deeply studied. The different types of implementations are reviewed and theoretical equations are derived and compared with simulations. There were selected four modes of operation for the Class-E amplifier, in order to perform the implementation of the output stage, and the subsequent comparison of results. This led to the selection of the mode with the best trade-off between efficiency and harmonics distortion, lower power consumption and higher output power. The optimal choice was a parallel circuit containing an inductor with a finite value. To complete the implementation of the PA in switching mode, a driver was implemented. The final block (output stage together with the driver) got 20 % total efficiency (PAE) transmitting 8 dBm output power to a 50 W load with a total harmonic distortion (THD) of 3 % and a total consumption of 28 mW. All implementations are designed using standard 130 nm CMOS technology. The operating frequency is 2.4 GHz and it was considered an 1.2 V DC power supply. The proposed circuit is intended to be used in a Bluetooth transmitter, however, it has a wider range of applications
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