Current-Mode Dielectric Spectroscopy for Liquid Permittivity Measurement.

In this work, we propose a current-mode dielectric spectroscopy integrated circuit (IC) for the detection of liquids permittivity at microwave frequency range. The current-mode sensing scheme presents wideband operation with enhanced dynamic range compared to conventional voltage-mode sensing approach. A low intermediate frequency (IF) receiver architecture further provides better performances in flicker noise, dc offset, and harmonic mixing that degrade a sensor accuracy in zero-IF receiver architecture.

Delta-sigma-modulated IFoF transmission system assisted by a correlative-level encoding technique.

A delta-sigma-modulated intermediate-frequency-over-fiber (IFoF) transmission system assisted by a correlative-level coding technique is proposed and experimentally demonstrated. Unlike conventional delta-sigma IFoF systems with multiple output levels to achieve higher signal quality or larger capacity, a correlative-level encoder is exploited as a second modulator preceded by the delta-sigma modulator. The encoder compresses the bandwidth of the delta-sigma modulated signal by creating a correlation between adjacent signal symbols.

Digital radio-over-fiber system with multi-pulse Manchester encoding-assisted delta-sigma modulation.

Two ∆Σ-modulated digital radio-over-fiber (DRoF) transmission systems that employ a multi-pulse Manchester encoder are proposed and experimentally evaluated. With a two-step modulation process comprised of ∆Σ modulation and multi-pulse Manchester encoding, a high frequency replica or image of a ∆Σ-digitized analog communication signal can be transmitted without significant power loss. This is achieved by exploiting the spectral characteristics of the modified Manchester code.

Non-contact Heartbeat Sensor using LC oscillator circuit.

This paper proposes non-contact heartbeat sensor using LC oscillator for personal healthcare. The signals from chest and wrist are measured using LC oscillator and electrodes. The proposed sensor can detect human heartbeat signal without direct contact to skin and is readily a portable heartbeat monitoring sensor.