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A new design based on wavelet analysis for the objective audiometry devices is proposed. The auditory brainstem response and 80-Hz auditory steady-state response (ASSR) are used in the objective audiometry devices for infants. For the aged, an objective audiometry device is used in anti-aging investigations, which enables the hearing acuity of awake adults to be tested with the 40-Hz ASSR. The ASSR...
We demonstrate a single-feeder WDM-PON system with enhanced reflection tolerance by applying dicode modulation on RSOA-based ONU. Extended reach of 90 km and 60 km are achieved for 1.25 Gb/s and 2.5 Gb/s uplink, respectively.
We present a novel method of generating an ac voltage using a programmable Josephson voltage standard. The ac voltage is generated by Δ-Σ (Delta-Sigma) modulation of multiple Josephson levels. Compared with an ac voltage generated by stepwise approximation, the Δ-Σ method reduces the low frequency harmonics of the generated signal. We demonstrate this method by generating a 90 Hz sine wave and measuring...
Electromagnetic Compatibility (EMC) is a very important topic for any professional dealing with electronics. However, teaching EMC concepts faces several difficulties like the fact that several subjects are concerned with it, the lack of time for it or the troubles to realize the effect of interferences. After reviewing the main textbooks and literature, the authors have believed desirable to complete...
Vibrato is a frequency modulation effect of the singing voice and is very relevant in musical terms. Its most important characteristics are the vibrato frequency (in Hertz) and the vibrato extension (in semitones). In singing teaching and learning, it is very convenient to provide a visual feedback of those two objective signal characteristics, in real-time. In this paper we describe an algorithm...
In this paper, a low-noise, low-power and low voltage Chopper Stabilized CMOS Amplifier (CHS-A) is presented and simulated using transistor model parameters of the AMS 0.35 μm CMOS process. Chopping is used to modulate the offset away from the output signal where it can be easily filtered out, providing continuous offset reduction which is insensitive to drift. The CHS was simulated using typical...
This paper looks at the Signal Transfer Function (STF) behaviour of cascaded Continuous-Time Delta-Sigma Modulators (CTDSMs) and how the flattening technique proposed by De Maeyer et al. can be used to reduce the effect of interfering signals and performance degradation for a subset of Excess Loop Delays (ELDs). Furthermore it will be shown that the noise-shaping performance of a CTDSM can be improved...
This work presents a simple approach to the correction of absolute gain errors in a tunable continuous-time bandpass Delta-Sigma modulator based on a Leslie-Singh architecture. The calibration is performed in the digital domain using the employed hardware. Thus, no additional analog circuitry overhead is added to the system. By tuning the center frequency of the analog resonator for correction, matching...
Radio coverage is limited by two parameters: (i) energy per bit radiated by the transmitter and (ii) BER performance of the receiver. In Ultra-Wideband Impulse Radio (UWB IR) the former is limited by the FCC Regulations while the latter depends on the detection algorithm. The fact that prevents the use of UWB IR devices in real applications is the unacceptable short radio coverage. The pulse compression...
In this paper, a design of the first-order Frequency-based Delta-Sigma Modulator (FDSM) utilizing multi-phase quantizer is presented. The VCO (Voltage-Controlled Oscillator) which behaves as a voltage-to-phase integrator will be proposed to generate multiple output phases. Each phase output from the VCO drives a counter using the proposed CMSA-FF (Current-Mirror Sense-Amplifier Flip-Flop), producing...
This paper presents a mixed-signal photo detection architecture that provides DC offset rejection of up to x5 beyond the dynamic range of the front-end amplifier while retaining the DC signal content of the physiological signal being detected. Closed-loop control of the mean input current is used to prevent saturation of the detector's front-end amplifier while frequency modulation of the illumination...
This paper presents a new concept for an effective design of quadrature band-pass ΣΔ modulators with built-in Signal Transfer Function (STF) filtering action and discusses the architectural level implementation issues for second and third order modulators based on delay line topologies. The methodology uses an architecture which locks the intermediate frequency (IF) to the sampling frequency for both...
The paper presents a low power and low chip area decimation filter for a 15-bits Σ-Δ analog-to-digital converter (ADC) designed for a flywheel MEMS gyroscope. In contrary to typical solutions, in which decimation is performed after each filtering stage, in the proposed approach all filter sections operate at the sampling frequency of the modulator. The low power dissipation is in this case achieved...
For the first time, modulation domain filters are proposed for removing beat type noises in video corrupted by unwanted external signals during the transmission process. We demonstrate the effectiveness of our proposed algorithm on picture carrier beat type noise observed in a real-world situation involving the transmission of critical video signals obtained from a traffic monitoring system. We compare...
Corrosion monitoring is a persistent problem relating to materials degradation. Modern plants have a need to predict and measure materials degradation due to corrosion during early stages and preferably on-line. So an overview of on-line electrochemical corrosion monitoring techniques is provided. The methods used in this study were: linear polarization resistance (LPR), electrochemical impedance...
This paper presents an online dereverberation algorithm that is derived within the maximum-likelihood expectation-maximization (ML-EM) framework. We formulate an overlap-save observation model for the multichannel blind problem in the DFT-domain. The modeling of acoustic channel impulse responses as random variables with a first-order Markov property facilitates the ensuing algorithm to cope with...
Impropriety in complex signal processing has been studied and used primarily in a communications context, but also in some cases where complex signals are generated by adding real signals in quadrature. We discuss the meaning of impropriety, and the associated use of complementary statistics, when a real-valued random process is improper in the frequency domain. Through the use of modulation signal...
Due to the randomness of the transmitted waveform, the range sidelobe after pulse compression of ground clutter in noise radar covers with the whole Doppler frequency domain, which forms a “noise floor” with the weaker signals drowned. Traditional moving target indicator (MTI) only applies to the radar with periodic transmitted signal for ground clutter suppression, while can not applies to noise...
Class-D amplifiers for portable devices are typically specified for supply voltage range ideal for use with lithium batteries [1–4]. The high efficiency of Class-D amplifiers makes them ideal for operation from boosted supplies. Moreover, in order to provide a better user experience in all multi-media applications, the new smart-phones and tablets are demanding for output peak power of higher than...
This paper presents an ultra-low-power (ULP) 2.3/2.4GHz multi-standard transmitter (TX) for wireless sensor networks and wireless body area networks. Several 2.3/2.4GHz wireless standards have been proposed for such applications, including IEEE802.15.6 (BAN) for body area networks, IEEE802.15.4 (Zigbee) and Bluetooth Low Energy (BLE) for sensor networks and IEEE802.15.4g (SUN) for smart buildings...
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