A VLSI CMOS delay oriented waveform converter for polyphasefrequency synthesizer

In this paper, we present a waveform converter implemented on a 0.25-μm CMOS technology using a dedicated design methodology (Delay Oriented Design). The circuit converts a square wave signal in both in-phase and quadrature-phase sinusoidal differential outputs. It also multiplies the frequency by seven. The output frequency range of this converter extends from 1.05 GHz up to 2.17 GHz. This converter is dedicated for the design of a third-generation mobile phone synthesizer using a double-loop architecture. For an output frequency of 2 GHz, the measured phase noise at 10-kHz offset from the carrier is -97 dBc/Hz. The circuit consumes 50 mW from a 2.5-V supply     

Influence of catalyst support geometry and wall thickness on NO x trap desulfation: rich/lean wobbling strategies and hexagonal cell supports for high SO2 selectivity during desulfation

Topics in Catalysis - This Synthetic Gas Bench (SGB) study focuses on the effect of cell geometry and wall thickness on the gasoline NO x trap functionality. The data show that besides a NO x trap...     

A linear 60 GHz 65 nm-CMOS power amplifier realization and characterization for OFDM signal

A millimeter-wave Power Amplifier (PA) based on a 65nm CMOS technology from STMicroelectronics has been designed. The targeted feature is the unlicensed band around 60 GHz suitable for wireless personal area network application (WPAN). To optimize the linearity, the PA is designed under class A biasing to have an output compression point (OCP₁) close to its saturated Power (P _sat). S-parameters and large signal measurement results are demonstrated and compared with electromagnetic simulations. The PA offers a P _sat of 8.3 dBm, an OCP₁ of 6 dBm and a gain of 6.7 dB. The die area is 0.29 mm² with pads. Considering those results, one-tone simulations are not sufficient to characterize the linearity performances of the PA in its real conditions of use. Consequently, two-tone simulations are firstly performed. After, linearity figures of merit (FoM) are discussed applying an orthogonal frequency-division multiplexing (OFDM) modulated signal. The PA offers an adjacent channel power ratio (ACPR) of 15 dB and an error vector magnitude (EVM) of 20% at PA compression operating mode.     

Organocatalyzed Conjugate Addition of Carbonyl Compounds to Nitrodienes/Nitroenynes and Synthetic Applications

The purpose of this study is to point out the synthetic utility of a new class of Michael acceptors (nitrodienes and nitroenynes). The highly enantioselective organocatalytic Michael addition of carbonyl compounds to these functionalized nitroolefins has been carried out in the presence of (S)‐diphenylprolinol silyl ether to achieve some interesting building blocks in high selectivities. The adducts thus obtained can be easily converted by taking advantage of the corresponding unsaturated carbon‐carbon bond. In presence of the double bond, metathesis or electrophilic activation could be carried out whereas in the presence of the triple bond electrophilic activation could be conducted. We thus focused on a gold‐catalyzed cyclization of the bis‐homopropargylic alcohol to afford the corresponding substituted tetrahydrofuran. Then, we also demonstrated that organic and gold catalysts were compatible in a one‐pot process. Indeed, we developed a one‐pot enantioselective organocatalytic Michael addition to a nitroenyne followed by a gold‐catalyzed acetalization/cyclization to achieve tetrahydrofuranyl ethers in high diastereo‐ and enantioselectivities with excellent yields.     

HiperLAN 5.4-GHz low-power CMOS synchronous oscillator

A 5.4-GHz 0.25-μm very-large-scale-integration CMOS synchronous oscillator (SO) is proposed in this paper, which is designed to act as a local oscillator for HiperLAN systems. The advantage of using such an oscillator in a double-loop frequency synthesizer is demonstrated. The design strategy leading to an optimized SO with regards to its synchronization range is described. A test chip is presented, which provides a 150-MHz synchronization range and a -97-dBc/Hz phase noise at 10-kHz offset from the 5-GHz carrier, while consuming only 5 mA from a 2.5-V supply     

A G/sub m/-C low-pass filter for zero-IF mobile applications with a very wide tuning range

A third-order G/sub m/-C Butterworth low-pass filter implementing G/sub m/-tuning and G/sub m/-switching to maximize the tuning range is described. This filter is intended to be used as a channel-selection/anti-aliasing filter in the analog baseband part of a zero-IF radio receiver architecture for multimode mobile communications. Its G/sub m/-switching feature allows extending the tuning range and adapting the power consumption. The filter's cutoff frequency ranges from 50 kHz to 2.2 MHz. An Input IP3 of up to +18 dBV/sub p/ is achieved, for a total worst-case power consumption of 7.3 mW for both I and Q paths, and an effective area of less than 0.5 mm/sup 2/ in a 0.25-/spl mu/m SiGe BiCMOS process. A new figure of merit is introduced for comparison of published low-pass tunable filters including noise, linearity, and tuning range.     

Design challenges of a 65 nm CMOS stacked folded differential PA structure for mobile communications

In this paper, a novel phase-locked loop (PLL) architecture with multiple charge pumps, which is used to design a fast-locking PLL and a low-phase-noise PLL, is proposed. The effective capacitance and resistance of the loop filter in terms of voltage is scaled up/down according to the locking status by controlling the magnitude and direction of the charge pump current. Two PLLs, one with a fast-locking characteristic and the other with a low-phase-noise characteristic, are designed and fabricated in a 0.35-μm CMOS process based on the proposed architecture. The fast-locking PLL has a locking time of less than 6 μs and a phase noise of −90.45 dBc/Hz at 1 MHz offset. The low-phase-noise PLL has a locking time of 25 μs, a phase noise of −105.37 dBc/Hz at 1 MHz offset, and a reference spur of −50 dBc. Both PLLs have an 851.2 MHz output frequency.     

One-step electrosynthesis of tetrahydrofuran and tetrahydropyran derivatives

The one-step electrosynthesis of tetrahydrofuran and tetrahydropyran derivatives was achieved by electrogenerating in N,N-dimethylformamide and at a mercury pool cathode, radical-anions of benzophenone or fluorenone in the presence of an equivalent of 1,3-dibromopropane 1 or 1,4-dibromobutane 2. In all electrolyses, a competition between ring alkylations and O- and C-alkylations of the keto group is observed. In the case of fluorenone, the spiroethers were isolated as the main compounds. Their yields after purification were respectively 41 and 50% in the presence of 1 and 2. For benzophenone, the yields of the cyclic ethers were low, due mainly to the competitive formation of bridged compounds; the yields of tetrahydrofuran and tetrahydropyran derivatives were respectively 10 and 23%.     

Novel Metal-Organic Chemical Vapor Deposition / T1F Annealing Route to Thin Films of Tl1Ba2Ca2Cu3O9+x

Thin films of TI₁Ba₂Ca₂Cu₃O_9+x have been grown on single crystal (110) LaAlO₃ by a metal-organic chemical vapor deposition process employing Ba(hfa)₂.mep, Ca(hfa)2.tet. and Cu(dpm)₂ (hfa = hexafluoroacetylacetonate; dpm = dipivaloylmethanate; tet = tetraglyme; mep =methylethylpentaglyme) as the volatile metal sources. A subsequent phase-selective annealing procedure accomplishes thallination using TIF in a bulk oxide pellet. The resulting films are nearly phase-pure and highly oriented and contain negligible fluoride by windowless energy-dispersive x-ray measurements. The films exhibit transport measured T_c = 103 K and J_c > 10⁴ A/cm² (77 K. 0 T) and at low temperatures retain J_c > 10⁵ A/cm² (5 K, 4.5 T) as measured by magnetic hysteresis.