10,465 research outputs found
Development of a dc-ac power conditioner for wind generator by using neural network
This project present of development single phase DC-AC converter for wind
generator application. The mathematical model of the wind generator and Artificial
Neural Network control for DC-AC converter is derived. The controller is designed to
stabilize the output voltage of DC-AC converter. To verify the effectiveness of the
proposal controller, both simulation and experimental are developed. The simulation and
experimental result show that the amplitude of output voltage of the DC-AC converter
can be controlled
A Fully-Integrated Quad-Band GSM/GPRS CMOS Power Amplifier
Concentric distributed active transformers (DAT) are used to implement a fully-integrated quad-band power amplifier (PA) in a standard 130 nm CMOS process. The DAT enables the power amplifier to integrate the input and output matching networks on the same silicon die. The PA integrates on-chip closed-loop power control and operates under supply voltages from 2.9 V to 5.5 V in a standard micro-lead-frame package. It shows no oscillations, degradation, or failures for over 2000 hours of operation with a supply of 6 V at 135Ā° under a VSWR of 15:1 at all phase angles and has also been tested for more than 2 million device-hours (with ongoing reliability monitoring) without a single failure under nominal operation conditions. It produces up to +35 dBm of RF power with power-added efficiency of 51%
Phase and Power Control in the RF Magnetron Power Stations of Superconducting Accelerators
Phase and power control methods that satisfy the requirements of
superconducting accelerators to magnetron RF sources were considered by a
simplified kinetic model of a magnetron driven by a resonant injected signal.
The model predicting and explaining stable, low noise operation of the tube
below the threshold of self-excitation (the Hatrree voltage in free run mode)
at a highest efficiency, a wide range of power control and a wide-band phase
control was well verified in experiments demonstrating capabilities of the
magnetron transmitters for powering of state of the art superconducting
accelerators. Descriptions of the kinetic model, the experimental verification
and a conceptual scheme of the highly-efficient magnetron RF transmitter for
the accelerators are presented and discussed.Comment: 10 pages, 15 figure
Silicon-Organic Hybrid (SOH) Mach-Zehnder Modulators for 100 Gbit/s On-Off Keying
Electro-optic modulators for high-speed on-off keying (OOK) are key
components of short- and mediumreach interconnects in data-center networks.
Besides small footprint and cost-efficient large-scale production, small drive
voltages and ultra-low power consumption are of paramount importance for such
devices. Here we demonstrate that the concept of silicon-organic hybrid (SOH)
integration is perfectly suited for meeting these challenges. The approach
combines the unique processing advantages of large-scale silicon photonics with
unrivalled electro-optic (EO) coefficients obtained by molecular engineering of
organic materials. In our proof-of-concept experiments, we demonstrate
generation and transmission of OOK signals with line rates of up to 100 Gbit/s
using a 1.1 mm-long SOH Mach-Zehnder modulator (MZM) which features a
{\pi}-voltage of only 0.9 V. This experiment represents not only the first
demonstration of 100 Gbit/s OOK on the silicon photonic platform, but also
leads to the lowest drive voltage and energy consumption ever demonstrated at
this data rate for a semiconductor-based device. We support our experimental
results by a theoretical analysis and show that the nonlinear transfer
characteristic of the MZM can be exploited to overcome bandwidth limitations of
the modulator and of the electric driver circuitry. The devices are fabricated
in a commercial silicon photonics line and can hence be combined with the full
portfolio of standard silicon photonic devices. We expect that high-speed
power-efficient SOH modulators may have transformative impact on short-reach
optical networks, enabling compact transceivers with unprecedented energy
efficiency that will be at the heart of future Ethernet interfaces at Tbit/s
data rates
Advanced digital modulation: Communication techniques and monolithic GaAs technology
Communications theory and practice are merged with state-of-the-art technology in IC fabrication, especially monolithic GaAs technology, to examine the general feasibility of a number of advanced technology digital transmission systems. Satellite-channel models with (1) superior throughput, perhaps 2 Gbps; (2) attractive weight and cost; and (3) high RF power and spectrum efficiency are discussed. Transmission techniques possessing reasonably simple architectures capable of monolithic fabrication at high speeds were surveyed. This included a review of amplitude/phase shift keying (APSK) techniques and the continuous-phase-modulation (CPM) methods, of which MSK represents the simplest case
Design of Low-Power Transmitter and Receiver Front End
This thesis focuses on the design of "RF front-end blocks" for the transmitter and receiver. The blocks include the low noise amplifier (LNA) and mixer downconversion at the receiving side, while the power amplifier includes the pre-driver circuit, and mixer up-conversion at the transmitter side. All of the blocks were designed in a 65nm design kit. The basics of these RF blocks are first described in chapters two to four. After that, the general principle of operations is then described and different topologies are discussed. In chapter 5 the proposed design is discussed. The proposed design is composed of a differential IDCS narrow band LNA, with a passive down-conversion mixer on the receiving side, designed for bluetooth low energy (BLE) applications, that operates at 2.4 GHz with a 1.2 V supply voltage. The overall conversion gain at the receiving side was found to be greater than 13 dB with a double side band noise figure of 8.3 dB having a 1 dB compression point of -11.8 dB, and with IIP3 of -2.06 dBm having a power consumption of 251 Ī¼watts. On the transmission side, a power amplifier with a pre-driver circuit and a passive up-conversion mixer has been designed to operate at a 1.2 V supply at the frequency of operation 2.4 GHz, having overall gain of 24 dB with maximum power added efficiency of 34% when using maximum output power of 11 dBm. The Cadence virtuoso design kit was used for simulation. Additionally, the layout considerations were discussed, followed by presentation of the post-layout results and graphs, and, finally, some conclusions have been drawn
Conceptual design of a 1-MW CW X-band transmitter for planetary radar
A proposed conceptual design to increase the output power of an existing X-band radar transmitter used for planetary radar exploration from 365 kW to 1 MW CW is presented. The basic transmitter system requirements as dictated by the specifications for the radar are covered. The characteristics and expected performance of the high-power klystrons are considered, and the transmitter power amplifier system is described. Also included is the design of all of the associated high-power microwave components, the feed system, and the phase-stable exciter. The expected performance of the beam supply, heat exchanger, and monitor and control devices is also presented. Finally, an assessment of the state-of-the-art technology needed to meet system requirements is given and possible areas of difficulty are summarized
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