This paper describes a new method to increase the performance of existing arbitrary waveform generators (AWG’s). By encoding the digital words using sigma-delta ( ) techniques, it is possible to decrease the noise floor in a narrow band while keeping the same memory requirements. Calibration techniques to deal with the nonidealities of the AWG are also presented and verified experimentally. Imp...

The paper deals with a bandpass sigma-delta modulator (BP SDM), which is used for conversion of signal from capacitive pressure sensor. This approach is absolutely new and unique, because this kind of modulator is utilized only for wireless and video applications. The main advantage of BP SDM is due to its defined band. That is why it is resistant against offsets of its sub-circuits. Another im...

A common architecture here unifies ordinary scalar deltasigma modulators, vector I/O delta-sigma modulators (including parallel banks of scalar ones), mismatch-shaping DACs, delta-sigma modulators incorporating mismatchshaping DACs in the conventional way, and something new: scalar or vector delta-sigma modulators incorporating spectral shaping of hardware mismatches as a natural and integral p...

This paper presents review on system level design of continuous time sigma delta modulator. A continuous time approach offers high accuracy with respect to discrete time modulator. Unity gain frequency and power can be achieved by continuous time design. as the sigma delta modulators are mainly implemented as discrete time circuits , a continuous time approach provides significant advantages fo...

We present recent progress of high-speed Mach-Zehnder modulator technologies for advanced modulation formats. Multi-level quadrature amplitude modulation signal can be synthesized by using parallel Mach-Zehnder modulators. We can generate complicated multi-level optical signals from binary data streams, where binary modulated signals are vectorially summed in optical circuits. Frequency respons...

To compensate for changes in ambient temperature, thermal flow sensors are usually heated to a constant temperature above ambient temperature. This operating mode, however, requires an extra ambient-temperature sensor. Using a simple model, it is shown that for a two-dimensional thermal flow sensor, similar compensation may be obtained by using a constant heating power, thus eliminating the nee...

The design of a 10.7-MHz 4-order fs/4 bandpass sigma-delta modulator with a double-delay single-opamp resonator plus double-sampling technique is proposed for GSM standard. The circuit is implemented in 0.35μ m double-poly, triple-metal CMOS process. Both behavioral-level and transistor-level simulation results are presented, and the circuit is expected to achieve >80 dynamic range with occupyi...

A new noise-shaping coding scheme is derived by using an autoregressive moving average model and by bounding and minimizing its reconstruction error. The stability of the system and performance can be analysed easily. All-zero first order and second order shaping filters are used to study the effect of the proposed scheme on the perceptual quality of speech signals.

Sigma-delta modulated systems have a number of very appealing properties and are, therefore, heavily used in analog to digital converters, amplifiers, and modulators. This paper presents new results which indicate that they may also have significant potential for general purpose arithmetic processing. The paper introduces new arithmetic processing structures for ternary (i.e., +1, 0, or −1) sig...

Abstract— In this paper, a generic and simple approach to design Continuous-Time Sigma-Delta Modulators (CT ƩΔMs) based on Finite Impulse Response Digital-to-Analog Converter (FIR DAC) is introduced. The numerical conversion from Continuous-Time to Discrete-Time allows the designer to explore complex modulator architectures and different feedback DAC shapes, without dealing with difficult equat...