The ever-growing machine-to-machine traffic in data centers has stimulated the increase of transceiver rate from 25 Gb/s/λ to 100 and beyond. It is believed that advanced modulation formats digital-to-analog converters (DACs) will be employed next generation short-reach transceivers. Digital pre-emphasis techniques are widely DAC-based transceivers compensate for high frequency roll-off due RF optoelectronics components optical However, digital essentially reduces magnitude signal low a flat...

This technology report validates the application of radio frequency (RF) coefficient reflection (Γ) measurement as a viable and accurate means to estimate starch content fresh cassava roots. A clear relationship between dry matter an indicator Γ is experimentally verified both from flour in water at different concentrations by direct probing root samples specific 30 MHz. prototype test instrument designed with goals portability, low cost ease use also reported. The displays estimated five...

This research explores the use of radio frequency (RF) return loss measurement to characterize cassava quality and estimate starch content roots, with new equivalent circuit models presented. While pure is non-conductive, charged ions in raw composite flour provides a potential marker for estimating cassava, which important design devices based on method. The study also raises questions further exploration, such as understanding pattern distribution electrolytic components fresh root...

In this paper we present a novel method to measure the free spectral range (FSR) and side-mode suppression ratio (SMSR) of an optoelectronic oscillator (OEO) by adjusting optical fiber length using path selector signal source analyzer. We have designed setup for single-loop OEO operating around 5 GHz 10 that features electrical bandpass filters suppression. The proposed approach makes it possible evaluate FSR SMSR OEOs with different paths without requiring changing spools or connectors....

This work reports a novel approach to extending the bandwidth of single stage distributed amplifiers (SSDAs). The three-stepped technique involves scaling down inductance on input artificial transmission line (ATL); creating high frequency resonance peak by addition shunt capacitance ATL; and compensating for resulting increased reflection with adapted negative resistance attenuation compensation techniques. Compared inductive-peaked cascode applied in SSDA which currently has highest...

This paper proposes a new amplifier topology, the matrix single stage distributed (M-SSDA). The employs only multiplicative gain, hence, potentially offering higher gain-per-device than both conventional DA and amplifier. Functionally similar to cascaded (C-SSDA), M-SSDA has advantages in smaller circuit footprint, potential for lower transmission line losses better noise performance. A 2-tiered common-emitter (CE) based on full foundry double heterojunction bipolar transistor (DHBT) model...

This paper analyses the noise performance of cascaded and matrix single stage distributed amplifiers (C-SSDA M-SSDA), together termed multiplicative amplifiers. The analytical expressions derived are verified applied in predicting figure a two- three-tiered M-SSDA based on full foundry model an InP double heterojunction bipolar transistor (DHBT). Based observations from study, we provide design considerations that optimise noise, gain bandwidth for this class amplifiers, improved utility...

The problem of simply and reliably estimating starch content cassava roots in the field is addressed by development a low cost test instrument that measures return loss at radio frequencies using coaxial probe. A clear relationship between measured root samples specific frequency 30 MHz first verified experimentally. prototype then designed with goals portability, simplicity use. displays 5 categories, from "low" to "high" an array LEDs. performance experimentally reliable correlation LED...

This paper proposes, for the first time, a transmission line synthesis approach to extending bandwidth of light- emitting diodes (LEDs) in context high capacity visible light communications links. As opposed more traditional pre-distortion, amplitude equalisation or driver circuitry based approaches, extension is achieved by incorporating LED diffusion capacitance into pseudo-artificial (p-ATL) cell with significantly improved and cut-off properties. With proposed technique, we show...

In this paper, we review the merit of single stage distributed amplifier (SSDA) and consider potential its derivative multiplicative topologies (the cascaded matrix SSDA) for ultra-wideband amplification. We highlight significant bandwidth advantage that SSDA topology offers higher gain DAs compared to conventional multi-stage DA. Furthermore, describe how available design trade-offs may be used offset inherent noise performance limitations family amplifiers. also report a new MMIC with 7.1...

This paper highlights the gain-bandwidth merit of single stage distributed amplifier (SSDA) and its derivative multiplicative topologies (i.e. cascaded SSDA (C-SSDA) matrix (M-SSDA)), for ultra-wideband amplification. Two new monolithic microwave integrated circuit (MMIC) amplifiers are presented: an MMIC with 7.1dB average gain 200GHz bandwidth; world's first M-SSDA, which has a 12dB 170GHz bandwidth. Both based on Indium Phosphide DHBT process 250nm emitter width. To authors best...

Modern data center networks (DCNs) require optical switches with ultra-low loss, ultra-fast reconfiguration speed, high throughput, and extinction ratio performances. In this work, we propose the design of a 5 × switch at 1550 nm based on piezo-actuator serving as translating input source, beam-steering system built spherical lenses to complete switching behaviour. An actuator speed is estimated 1.55 μ s latency for single connection demo circuit. We further simulate end-to-end in commercial...

The opto-electronic oscillator is a well-known microwave photonic device that produces high-frequency signals in the range. One of main advantages it with low phase noise thanks to resonator's properties. In most cases faces problem generating side modes besides oscillation signal due non-ideal filtering. this paper we propose solution for additional suppression these undesired harmonics using combination two slightly detuned bandpass microstrip filters. We report an improvement side-mode...

We demonstrate a performance improvement of dual-comb based optical analog-to-digital conversion methods. Through improved front-end design, we obtain 4.5 bits ENOB up to 12.5 GHz, representing 10 dB SINAD enhancement compared previous results.

In this paper, we derive new models that describe the noise voltage and equivalent input current spectral densities for multiplicative distributed amplifiers. Based on derived models, design optimisation techniques to minimise contribution of transimpedance amplifiers based DA topologies are proposed.