In this paper we present a prototype continuous time Σ∆-modulator in a 0.35 μm technology. The circuit has a 6-bit internal quantizer. Through the combination of a modified architecture and comparator interpolation this high quantizer resolution is achieved with only 15 comparators. However, it turns out that this approach imposes a severe speed constraint on the analog adder circuit. The modul...

A design flow for ΔΣ modulators is illustrated, allowing quantization noise to be shaped according to an arbitrary weighting profile. Being based on FIR NTFs, possibly with high order, the flow is best suited for digital architectures. The work builds on a recent proposal where the modulator is matched to the reconstruction filter, showing that this type of optimization can benefit a wide range...

SLAC National Accelerator Laboratory (SLAC) has initiated a program to design and build a Marx-topology modulator to produce a relatively compact, low-cost, high availability klystron modulator for the International Linear Collider (ILC). Building upon the success of the P1 Marx, the SLAC P2 Marx is a second-generation modulator whose design further emphasizes the qualities of modularity and hi...

This paper presents a complete set of SIMULINK ® models, which allow exhaustive behavioral simulations of any sigma-delta modulator to be performed. The proposed set of models takes into account most of the sigma-delta modulator non-idealities, such as sampling jitter, kT/C noise and operational amplifier parameters (noise, finite gain, finite bandwidth, slew-rate and saturation voltages). For ...

Ultra-small modulator and demodulator for 10 Gb/s differential phase-shift-keying (DPSK), using silicon-based microrings, are proposed. A single-waveguide microring modulator with over-coupling between ring and waveguide generates a DPSK signal, while a double-waveguide microring filter enables balanced DPSK detection. These modulator and demodulator are characterized. A trade-off between patte...

A double sampled second order ΣΔ modulator with an analog look ahead (ALA) approach is presented. The proposed architecture provides an extra clock period to be used for the quantization. The feedforward path in both integrators allows the further reduction of the output voltage swing, relaxing also the slew-rate requirements of the op-amps. Moreover, the modulator enables the reduction of the ...

A new design approach of a digital delta-sigma modulator with small output fluctuation is proposed. The digital delta-sigma modulators are used in the digital-analog converters, the fractional-N phase lock loop, etc. and its output fluctuation is one of the important performances although a higher order modulator often produces large fluctuations. In this work, the noise shaping filter of the m...

Linear dichroism and birefringence artifacts are a major source of concern in transient circular dichroism measurements. They mainly arise from interaction of an imperfectly circular polarized probe beam with a nonisotropic sample. We present in this article a procedure to generate mid-IR pulses of highly symmetric left and right handed circular or elliptical polarization states for transient V...

In order to design high performance sigma-delta A/D converters, it is essential to estimate the Figure-Of-Merit in the design process. This paper describes the design of a power/performance efficient single-loop multibit sigmadelta modulator for wireless applications. Power dissipation is minimized by optimizing the architecture and by a careful design of analog circuitry. A 3 order 4-bit Σ-∆ m...

A novel integrable modulator consisting of a polarization modulator and a polarizer is proposed for constructing a high-performance analog photonic link. By adjusting a polarization controller placed before the modulator, both amplitude modulation and phase modulation with adjustable ratio between them are implemented. This feature is used to shift the peak of the frequency response of a disper...