Current Issue : October - December Volume : 2013 Issue Number : 4 Articles : 8 Articles
This paper presents a design of a reconfigurable low noise amplifier (LNA) for multiband orthogonal frequency division\r\nmultiplexing (MB-OFDM) ultra wideband (UWB) receivers. The proposed design is divided into three stages; the first one is a\r\ncommon gate (CG) topology to provide the input matching over a wideband.The second stage is a programmable circuit to control\r\nthe mode of operation. The third stage is a current reuse topology to improve the gain, flatness and consume lower power. The\r\nproposed LNA is designed using 0.18 ??m CMOS technology. This LNA has been designed to operate in two subbands of MBOFDMUWB,\r\nUWB mode-1 andmode-3, as a single or concurrentmode. The simulation results exhibit the power gain up to 17.35,\r\n18, and 11 dB for mode-1, mode-3, and concurrent mode, respectively.The NF is 3.5, 3.9, and 6.5 and the input return loss is better\r\nthan -12, -13.57, and -11 dB over mode-1, mode-3, and concurrent mode, respectively. This design consumes 4mWsupplied from\r\n1.2 V....
An inductorless phase-locked loop with subharmonic pulse injection locking was realized (PLL area: 0.11mm2) by adopting 90nm\r\nSi CMOS technology. The proposed circuit is configured with two cascaded PLLs; one of them is a reference PLL that generates\r\nreference signals to the other one from low-frequency external reference signals. The other is a main PLL that generates highfrequency\r\noutput signals. A high-frequency half-integral subharmonic locking technique was used to decrease the phase noise\r\ncharacteristics. For a 50 MHz input reference signal, without injection locking, the 1 MHz offset phase noise was -88 dBc/Hz at a\r\nPLL output frequency of 7.2GHz (= 144 Ã?â?? 50MHz); with injection locking, the noise was -101 dBc/Hz (spur level: -31 dBc; power\r\nconsumption from a 1.0V power supply: 25mW)....
This paper presents the design of ultra-wideband low noise amplifier (UWB LNA). The proposed UWB LNA whose bandwidth\r\nextends from 2.5GHz to 16GHz is designed using a symmetric 3D RF integrated inductor. This UWB LNA has a gain of 11 �± 1.0 dB\r\nand a NF less than 3.3 dB.Good input and output impedance matching and good isolation are achieved over the operating frequency\r\nband. The proposed UWB LNA is driven froma 1.8V supply.The UWB LNA is designed and simulated in standard TSMC 0.18 pm\r\nCMOS technology process...
Multipixel cameras represent an emerging topology for arrays receivers, improving speed and accuracy of both security scanning\r\nsystems and radioastronomical sky surveys by means of a matrix of phased elements. Difficulties in the generation and proper\r\ndistribution to each pixel of the local oscillator signal still limit their use to frequency ranges below a few GHz or at least\r\nseriously affect the complexity of the implementable cameras. This work presents a full comparison between two possible system\r\narchitectures, alternatively based on LO frequency multiplication or subharmonic mixing strategies, aiming to overcome the\r\naforesaid limitations: design and performance of two compact test vehicles in MMIC technology, both operating in the Q-band\r\nfrequency range with ultrabroadband IF section, are reported....
This paper reports the latest advances on millimeter-wave CMOS voltage-controlled oscillators (VCOs). Current state-of-the-art\r\nimplementations are reviewed, and their performances are compared in terms of phase noise and figure of merit. Low power and\r\nlow phase noise LC-VCO and ring oscillator designs are analyzed and discussed. Design and performance trends over the last\r\ndecade are provided and discussed.The paper shows how for the higher range of millimeter-waves (>60GHz) the performances of\r\nring oscillators become comparable with those of LC-VCOs....
The duration of rainfall events as a function of precipitation rate is investigated in this paper. The experimental data used in this\r\nstudy were measured along a rain gauge network with 8 pluviographs located in the Amazon region. The most important point to\r\nbe highlighted in this study is the evidence of a correlation between rain and fade events durations observed in a 12GHz satellite\r\nlink. This result is quite important under the engineering point of view, once it can be used in the design of improvement techniques\r\nfor low availability satellite systems....
Systematic design of a low power, wideband and multi-bit continuous-time delta-sigma modulator (CTDSM) is presented. The\r\ndesign methodology is illustrated with a 640 MS/s, 20MHz signal bandwidth 4th order 2-bit CTDMS implemented in 0.18 ??m\r\nCMOS technology. The implemented design achieves a peak SNDR of 65.7 dB and a high dynamic range of 70 dB while consuming\r\nonly 19.7mW from 1.8V supply. The design achieves a FoM of 0.31 pJ/conv. Direct path compensation is employed for one\r\nclock excess loop delay compensation. In the feedforward topology, capacitive summation using the last opamp eliminates extra\r\nsummation opamp....
Filters based on film bulk acoustic resonators (FBARs) are widely used for mobile phone applications, but they can also address\r\nwideband aerospace requirements. These devices need high electromechanical coupling coefficients to achieve large band pass\r\nfilters.The piezoelectric material LiNbO3 complies with such specifications and is compatible with standard fabrication processes.\r\nIn this work, simple metalââ?¬â?LiNbO3ââ?¬â?metal structures have been developed to fabricate single FBAR elements directly connected\r\nto each other on a single chip. A fabrication process based on LiNbO3/silicon Au-Au bonding and LiNbO3 lapping/polishing\r\nhas been developed and is proposed in this paper. Electrical measurements of these FBAR filters are proposed and commented\r\nexhibiting filters with 8% of fractional bandwidth and 3.3 dB of insertion losses. Electrical measurements show possibilities to\r\nobtain 14% of fractional bandwidth. These devices have been packaged, allowing for power handling, thermal, and ferroelectric\r\ntests, corresponding to spatial conditions....
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