1,721,042 research outputs found
Some structures for neural based A/D conversion
Some structures for neural based A/D conversion are presented. Experimental results on the proposed topologies are reported. The structures described are particularly suitable for the realisation of a low-cost, easily expandable voltmeter for consumer application
Saperi minimi e autovalutazione: un progetto interIRRSAE in rete
Il progetto e' visibile in rete all'indirizzo: http://www.hermescuole.na.it/sm
Saperi minimi e autovalutazione: un progetto interIRRSAE in rete
Il progetto e' visibile in rete all'indirizzo: http://www.hermescuole.na.it/sm
A direct wireless signals receivers architecture with noise sources modeling
The paper focuses on the modeling of the noise contributions in a receiver architecture based on the sub-sampling theory. A detailed noise analysis is reported, leading to improved receiver design. The proposed model includes switched-capacitor noise, quantization noise and LNA noise. Receiver performance was evaluated using the GSM standard as a reference
Single-layer dual frequency patch antenna
A configuration for a slotted patch antenna is introduced which allows two separate operating frequencies. Both of these frequencies are associated with a radiating mode almost identical to that of a standard patch. The two resonances are related to the patch width and the slot/patch length, respectively
Equivalent circuit model of GaAs MMIC‐coupled planar spiral inductors
The article describes a lumped component model which accounts for coupling between inductors in GaAs MMIC design. The model was developed using a full-wave approach. The validity of the proposed circuit has been successfully tested. Experimental results are reported to validate the model
Low-power Tx module for high-resolution continuous programmable phase shift
A novel phase shifter topology for digital phased antenna arrays based on a low-power phase control block joint with an innovative PLL design is presented. Experimental results obtained by a prototype are reported validating the architecture capabilitie
Wireless Sensor Networks Time Synchronization Algorithms and Protocols Message Complexity Comparison: The Small-Size Star-Topology Case
S-band digital downconverter for radar applications based on a GaAs MMIC fast sample-and-hold
A digital coherent-downconverter
configuration is described whose operation
principle is based on the theory of subharmonic
sampling for narrowband waveforms. This
configuration uses a fast sampler, operating at
microwave frequencies, for directly demodulating
the in-phase and quadrature components of a
complex input waveform, yielding a sampled
sequence in a suitable format for subsequent
analogue-to-digital conversion. Unlike the
conventional double-conversion coherentsuperheterodine
architecture, the proposed
configuration offers attractive features in terms of
cost and complexity and appears particularly
suitable for the implementation of the front-end
unit in a coherent receiver. An experimental
prototype, based on a very fast GaAs MMIC
sample-and-hold (SH) circuit, has been
implemented for validating the operation
principle. Complex demodulation of a 1 GHz
input waveform is demonstrated, with 6-bit
equivalent accuracy
Robust behavioral non uniform look-up table spacing in adaptive digital baseband predistortion technique for RF power amplifier
The paper introduces a linearization technique based on a modified complex gain predistorter. The look-up table (LUT) digital adaptive predistortion (PD) approaches are effective for power amplifier (PA) linearization for reducing the PA power back-off and increasing the efficiency. Unlike other LUT predistorter based on uniform spacing of the LUT entries, the paper proposes a robust and behavioral method. The density of the table entries is directly proportional to the amplifier nonlinearity so the optimum table spacing could be realized. Besides, the proposed algorithm is able to optimize the LUT spacing without prior knowledge of the PA characteristics or input signal statistics and the LUT index calculation is made by a simple and fast algorithm
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