Several techniques have been proposed for estimating and compensating for the effects of quadrature modulators and demodulators. Several of them will be discussed in this survey including those that observe the envelope of signals, the pilot tones of OFDM signals, and others.

A novel Σ∆ modulator is presented with lower power consumption and higher Signal to Noise Ratio (SNR) than the conventional modulator for a given order. The novel modulator is applied in analog-to-digital converters of RF receivers. The same modulator architecture is used for GSM and WCDMA receivers differing only the in Oversampling Ratio (OSR). The modulator was designed using switched capaci...

This paper proposes the design of micro power Sigma-delta modulator with using verilog HDL based on been mapped on small commercially available FPGAs (Field Programmable Gate Arrays). This Sigma-delta modulator design is paid special attention to its low power application of portable electronic system in digitizing biomedical signals such asElectrocardiogram(ECG),Electroencephalogram(EEG) etc. ...

A bovine brain protein recently discovered as an inhibitor of cyclic nucleotide phosphodiesterase has been partially purified and characterized. This inhibitor protein specifically counteracts the activation of phosphodiesterase by the Ca2+-dependent protein modulator. It shows no inhibitory activity against the Ca2+ -independent form of phosphodiesterase or the basal activity of the Ca2+-activ...

A Sigma-delta modulator is designed in 180nm CMOS process for digital Audio applications. This design is simulated on S-Edit of Tanner EDA tool. In this design continuous time sigma-delta modulator is implemented to reduce the noise problem. This sigma-delta modulator also helps to reduce power consumption of circuit. In these design two stage op-amps is used to implement modulator. Also this d...

Sigma-delta ACD has two main parts: analog modulator and digital filter, the performance of modulator determines the performance of sigma-delta ADC, so the design of modulator is very important. The paper introduces the principle of sigma-delta AD modulator with high accuracy and the applied over sampling technique, noise shaping technique and multi-bit quantizer technique. Determining the desi...

High efficiency and a compact footprint are desired properties for electro-optic modulators. In this paper, we propose, theoretically investigate experimentally demonstrate recirculating phase modulator, which increases the modulation by modulating optical field several times in non-resonant waveguide structure. The 'recycling' of light is achieved looping path that exits modulator back couplin...

Modulator is an endogenous low-molecular-weight regulator of both glucocorticoid and mineralocorticoid receptors as well as protein kinase C. Structural analysis of modulator purified to apparent homogeneity suggests that it is a novel ether aminophosphoglyceride. In this report, we show that modulator inhibits cytosolic human glucocorticoid receptor (GR) complex activation as measured by DNA-c...

We investigated the mode of action of PNU-120596, a type II positive allosteric modulator of the rat α7 nicotinic acetylcholine receptor expressed by GH4C1 cells, using patch-clamp and fast solution exchange. We made two important observations: first, while PNU-120596 rapidly associated to desensitized receptors, it had at least hundredfold lower affinity to resting conformation, therefore at 1...

This paper proposes a new realization technique of image rejection function by noise-coupling architecture, which is used for a complex bandpass ΔΣAD modulator. The complex bandpass ΔΣAD modulator processes just input I and Q signals, not image signals, and the AD conversion can be realized with low power dissipation. It realizes an asymmetric noise-shaped spectra, which is desirable for such l...