Joint Compensation of Power Amplifier Nonlinearity and Quadrature Modulator Mismatches Based on Jacobi Polynomials Nonlinear Model

An electro-optic (EO) modulator using a TiO2 slot hybrid waveguide has been designed and fabricated. Optical mode calculations revealed that the mode was primarily confined within the slots when using a double-slot configuration, thus achieving a high EO activity experimentally. The TiO2 slots also acted as an important barrier to induce an enhanced DC field during the poling of the EO polymer ...

The design and characterization of a slow-wave series push-pull traveling wave silicon photonic modulator is presented. At 2 V and 4 V reverse bias, the measured -3 dB electro-optic bandwidth of the modulator with an active length of 4 mm are 38 GHz and 41 GHz, respectively. Open eye diagrams are observed up to bitrates of 60 Gbps without any form of signal processing, and up to 70 Gbps with pa...

An analog front-end composed of a preamplifier and a Σ-∆ modulator is proposed and implemented for digital hearing aid chip. Combined gain control (CGC), the technique, which incorporates an automatic gain control (AGC) with an exponential gain control (EGC), is employed to enlarge dynamic range and reduce power consumption. The proposed Σ-∆ modulator exploits adaptive-SNR technique, which gene...

The trend in silicon photonics, in the last few years has been to reduce waveguide size to obtain maximum gain in the real estate of devices as well as to increase the performance of active devices. Using different methods for the modulation, optical modulators in silicon have seen their bandwidth increased to reach multi GHz frequencies. In order to simplify fabrication, one requirement for a ...

A third-order single-bit CT-ΔΣ modulator for generic biomedical applications is implemented in a 0.15 μm FDSOI CMOS process. The overall power efficiency is attained by employing a single-bit ΔΣ and a subthreshold FDSOI process. The loop-filter coefficients are determined using a systematic design centering approach by accounting for the integrator non-idealities. The single-bit CT-ΔΣ modulator...

A novel application and generalization of sigma–delta ( ) modulation has emerged in three-phase power-electronic converters. A conventional modulator with scalar signals and binary quantizer is generalized to a modulator with vector signals and a hexagonal quantizer. Indeed, power-electronic switching states may be thought of as determining the quantizer outputs. The output spectrum is a key pe...

In this paper the design of a low power sigma-delta modulator with dynamic biasing is presented. This design uses simple analog and digital components to achieve the low power purpose. In order to get a 12-bit resolution over the 4-kHz signal bandwidth for voice band applications such as PCM CODECs, an optimum choice is the second order modulator with an oversampling ratio of 128 and sampling f...

Sigma delta modulation is a popular technique for high-resolution analog-to-digital conversion and digital-to-analog conversion. We investigate chaotic phenomena in multibit first-order sigma-delta modulators. Particular attention is placed on the occurrence of periodic orbits or limit cycles. These may result in idle tones audible to the listener when sigma-delta modulation is used for audio s...