A Band-pass ΔΣ Modulator with Variable Center Frequency

High-performance variable band-pass/band-stop state-space digital filters using Gramian-preserving frequency transformation

A 1.2 GHz Band-Pass Sigma Delta Analog to Digital Modulator with Active Inductor based Resonators

This paper presents a 1.2 GHz continuous time 6 order band-pass Sigma Delta Analog to Digital modulator in IBM 0.18 um CMOS technology. Traditional RLC circuits, with spiral inductors as resonators, were replaced with active inductor based resonators with negative impedance circuits to enhance the quality factor, reduce chip area and eliminate post processing needs. Simulink and Cadence simulat...

A 1.2 V, 38 microW Second-Order DeltaSigma Modulator with Signal Adaptive Control Architecture

A 1.2 V, 38 μW second-order ΔΣ modulator (ΔΣM) with a Signal Adaptive Control (SAC) architecture is fabricated in a 0.35 μm standard CMOS technology (Vt,n = 0.6V, Vt,p = -0.8V). This modulator achieves 75 dB dynamic range and 63 dB of peak SNDR at 6.8kHz Nyquist rate and an oversample ratio of 64. The proposed architecture effectively reduces the power dissipation while keeping the modulator pe...

V-band bandpass filter with continuously variable centre frequency

A second-order bandpass filter (BPF) with continuously variable centre frequency tuning is presented in this article. Evanescent-mode cavity resonators with variable capacitive loadings are used as tuning elements. Tuning is achieved by means of micro-electromechanical-systems (MEMS)-actuated highly conductive rigid fingers that feature an out-of-plane deflection. For an applied DC bias voltage...

Two-dimensional phononic crystal with tunable narrow pass band: Application to a waveguide with selective frequency

We study theoretically the propagation of elastic waves in two-dimensional composite media composed of a square array of hollow steel cylinders embedded in water using the finite-difference time-domain method. These composite media constitute a class of acoustic band gap materials with narrow pass bands in their transmission stop bands. The frequency at which the pass band occurs is tunable by ...