Signal Conditioning Block Research Articles

CMOS Detector Staggered Array Module for Sub-Terahertz Imaging on Conveyor Belt System.

A complementary metal-oxide-semiconductor (CMOS) detector array is proposed to improve the sub-terahertz imaging resolution for objects in the conveyor belt system. The image resolution is limited to the implemented configuration, such as the wide spacing in the detector array, the high conveyor belt speed, and the slow response of the signal conditioning block. The proposed array can improve the image resolution in the direction perpendicular to the movement of the belt, which is determined by the size and interval of the detector pixel, by configuring the array into two replaceable columns located at the misaligned horizontal positions. Replaceable detector unit pixels are individually attached to the motherboard after measuring and evaluating the detection performance to construct the proposed array. The intensities of 32 detector pixels placed under the conveyor belt with a width of 160 mm were initially calibrated in every image, including the beam pattern of 0.2 THz signals generated from the gyrotron. The image resolution of the perpendicular direction obtained from the proposed array was measured to be approximately 5 mm at a conveyor belt speed of 16 mm/s, demonstrating a 200% improvement in resolution compared to the conventional linear array under the same conditions.

Silicon Carbide Bipolar Analog Circuits for Extreme Temperature Signal Conditioning

This paper presents functional high-temperature analog circuits in silicon carbide bipolar technology. The circuits will collectively form the analog signal conditioning block for a wireless telemetry system in an extreme environment (above 400°C). The signal conditioning block is composed of a low dc gain operational amplifier, a negative voltage charge pump (CP), an RC oscillator, and a voltage regulator. The circuits are tested up to 450°C. The measured open-loop gain for the amplifier at 450°C is 30 dB. The regulator provides approximately 9-V output at 450°C for a fixed load current of up to 18 mA and an applied reference of 4.5 V. The negative voltage CP requires an oscillating signal at its input, which is provided by the RC cross-coupled oscillator. The CP provides about −5 V at 450°C.

A novel flip-flop based error free, area efficient and low power pipeline architecture for finite impulse recursive system

An error free, area efficient and low power pipeline architecture for finite impulse recursive signal processing system on chip (SOC) is proposed. The pipeline stage is implemented for the FIR filter which forms the signal conditioning block of the SOC in 60 and 90 nm technology. The design, implementation and testing is performed using Altera Quartus 9.1, cyclone device family for 60 and 90 nm technology. The pipelining is designed with 3 and 5 stages. The combinational block consists of processing elements like array multiplier and ripple carry adder. The registers of the pipelining is designed using normal D flip-flop, Autogated and Razor flip-flop. The pipelining architecture is further extended towards shared component architecture. The proposed shared component architecture reduces the critical path, number of components by which area is reduced and power consumption. The proposed design reduces the error with fewer timing penalty. The results are compared with existing methods and the efficiency of proposed method is improved. The proposed flip flop is compared with the existing flip-flop and found that the static power consumption is reduced by 8% and dynamic power consumption by 56%. The proposed pipelined shared component architecture reduces the power consumption by 10% for static power and 75% for dynamic power. From the machine cycles execution analysis it is found that the proposed design saves clock cycles when an error occurs. When area is considered the proposed architecture contains less number of multipliers.

1024-Pixel CMOS Multimodality Joint Cellular Sensor/Stimulator Array for Real-Time Holistic Cellular Characterization and Cell-Based Drug Screening.

This paper presents a fully integrated CMOS multimodality joint sensor/stimulator array with 1024 pixels for real-time holistic cellular characterization and drug screening. The proposed system consists of four pixel groups and four parallel signal-conditioning blocks. Every pixel group contains 16 × 16pixels, and each pixel includes one gold-plated electrode, four photodiodes, and in-pixel circuits, within a pixel footprint. Each pixel supports real-time extracellular potential recording, optical detection, charge-balanced biphasic current stimulation, and cellular impedance measurement for the same cellular sample. The proposed system is fabricated in a standard 130-nm CMOS process. Rat cardiomyocytes are successfully cultured on-chip. Measured high-resolution optical opacity images, extracellular potential recordings, biphasic current stimulations, and cellular impedance images demonstrate the unique advantages of the system for holistic cell characterization and drug screening. Furthermore, this paper demonstrates the use of optical detection on the on-chip cultured cardiomyocytes to real-time track their cyclic beating pattern and beating rate.

Signal-Conditioning Block of a 1 × 200 CMOS Detector Array for a Terahertz Real-Time Imaging System.

A signal conditioning block of a 1 × 200 Complementary Metal-Oxide-Semiconductor (CMOS) detector array is proposed to be employed with a real-time 0.2 THz imaging system for inspecting large areas. The plasmonic CMOS detector array whose pixel size including an integrated antenna is comparable to the wavelength of the THz wave for the imaging system, inevitably carries wide pixel-to-pixel variation. To make the variant outputs from the array uniform, the proposed signal conditioning block calibrates the responsivity of each pixel by controlling the gate bias of each detector and the voltage gain of the lock-in amplifiers in the block. The gate bias of each detector is modulated to 1 MHz to improve the signal-to-noise ratio of the imaging system via the electrical modulation by the conditioning block. In addition, direct current (DC) offsets of the detectors in the array are cancelled by initializing the output voltage level from the block. Real-time imaging using the proposed signal conditioning block is demonstrated by obtaining images at the rate of 19.2 frame-per-sec of an object moving on the conveyor belt with a scan width of 20 cm and a scan speed of 25 cm/s.

A Multi-Modality CMOS Sensor Array for Cell-Based Assay and Drug Screening.

In this paper, we present a fully integrated multi-modality CMOS cellular sensor array with four sensing modalities to characterize different cell physiological responses, including extracellular voltage recording, cellular impedance mapping, optical detection with shadow imaging and bioluminescence sensing, and thermal monitoring. The sensor array consists of nine parallel pixel groups and nine corresponding signal conditioning blocks. Each pixel group comprises one temperature sensor and 16 tri-modality sensor pixels, while each tri-modality sensor pixel can be independently configured for extracellular voltage recording, cellular impedance measurement (voltage excitation/current sensing), and optical detection. This sensor array supports multi-modality cellular sensing at the pixel level, which enables holistic cell characterization and joint-modality physiological monitoring on the same cellular sample with a pixel resolution of 80 μm × 100 μm. Comprehensive biological experiments with different living cell samples demonstrate the functionality and benefit of the proposed multi-modality sensing in cell-based assay and drug screening.

FPGA Based Heartbeats Monitor with Fingertip Optical Sensor

The heart is an organ of human body which has a vital function, small abnormalities can have a big impact on the performance of the body. Heart disease is the number one cause of death in the world. Examination of the heart can be detected from blood flow in the fingertips, in order to obtain information about the number and rhythm of the heartbeat. This research aims to design and implement the FPGA board to monitor the heart rate with optical sensors.The results of this study are expected to facilitate the patient's medical team or independently in detecting heart health. The series is composed of blocks of sensors, signal conditioning block, the block pulse counter, block timer 10 seconds and blocks the viewer. Based on the test results of the 10 respondents with a variety of age and gender, has built a tool that the percentage error of 3.94%.

A Compact Ka-Band Doppler Radar Sensor for Remote Human Vital Signal Detection

This paper presents a compact K-band Doppler radar sensor for human vital signal detection that uses a radar configuration with only single coupler. The proposed radar front-end configuration can reduce the chip size and the additional RF power loss. The radar front-end IC is composed of a Lange coupler, VCO, and single balanced mixer. The oscillation frequency of the VCO is from 27.3 to 27.8 GHz. The phase noise of the VCO is ?91.2 dBc/Hz at a 1 MHz offset frequency, and the output power is ?4.8 dBm. The conversion gain of the mixer is about 11 dB. The chip size is 0.89×1.47 ㎟. The compact Ka-band Doppler radar system was developed in order to demonstrate remote human vital signal detection. The radar system consists of a Ka-band Doppler radar module with a 2×2 patch array antenna, baseband signal conditioning block, DAQ system, and signal processing program. The front-end module size is 2.5×2.5 ㎠. The proposed radar sensor can properly capture a human heartbeat and respiration rate at the distance of 50 cm.

Cost Effective, Versatile, High Performance, Spectral Analysis in a Synthetic Instrument

This paper described a versatile block of signal conditioning options that process raw data samples from the A/D converter and deliver a filtered and resampled version of those data samples to a conventional FFT based spectrum analyzer. The conditioning performs a number of important processing functions. These include spectral translation to baseband, noise bandwidth reduction to signal bandwidth, and arbitrary resampling to obtain specified spectral spacing with available sized FFTs. The versatility of an FPGA based processor and signal conditioning block enables the use of the signal conditioner blocks to align sample rate with transform sizes without the need to vary input sample clock rate or the cut off bandwidth of analog anti-alias filters in the signal path. A straw man set of specifications for the spectrum analyzer was proposed and used as the basis of the simulations presented in this paper. The processing described here reflects the great versatility and flexibility available to the system designer. Broader bandwidths and greater dynamic range options can be quickly accommodated in the architecture presented here.

A Remote Compact Sensor for the Real-Time Monitoring of Human Heartbeat and Respiration Rate

A remote compact sensor system for the detection of human vital signs (heartbeat and respiration rate) is presented. The frequency band of 24 GHz is employed for remote sensing. For the compact size, the developed sensor uses a circularly polarized electromagnetic wave with a single antenna. The sensor system is composed of radio-frequency circuits, a signal conditioning block, a data-acquisition unit, and a signal-processing part. The peak detection of the power spectral density with a tracking algorithm is utilized for the real-time detection of human vital signs. The measurement result is compared with the commercial fingertip sensor. The comparison result shows excellent agreement.

Field data comparisons of MEMS accelerometers and analog geophones

Geophones have been the motion sensor of choice in oil and gas exploration surveys for many years and for good reason: they require no electrical power to operate, are lightweight, robust, and able to detect extremely small ground displacements. However, the seismic industry recently has developed considerable interest in microelectro mechanical systems (MEMS) accelerometers, which are similar to those used to sense accelerations for airbag deployment and missile guidance (among many other uses). The MEMS element is tied to an application specific integrated circuit (ASIC) that includes sensor signal conditioning, feedback control, and digitization blocks. The result is a custom-built unit for seismic applications that requires a power supply to operate.

A Capacitive-Based Accelerometer IC Using Injection-Nulling Switch Technique

This paper presents a new fully integrated sensing interface and signal-conditioning application-specific integrated circuit (ASIC) for automotive accelerometers based on an ldquoinjection-nulling switchrdquo (INS) technique. The INS technique simplifies the design of both the switched-capacitor (SC) sensing amplifier and its supporting building blocks without jeopardizing its performance. This is done by counteracting the impact of charge injection and clock-feedthrough effects on sensitivity, resolution, and offset. It also decreases the number of opamps, capacitors, and switches being used. This results in reduction of power consumption, potential switching noise, and noise (sampled thermal noise which increases with the number of SC pairs being used) in the ASIC. A two-chip approach has been adopted in the implementation, with sensing element and ASIC. The built-in trimming circuitry and signal-conditioning blocks, which includes a self-test circuit, are implemented internally to eliminate the need for external components. The experimental results have shown that the sensing system IC has achieved a power consumption of 10 mW (2 mA at 5 V), a maximum noise root spectral density of 11.87 equivalent to rms noise root spectral density of 0.187 at 15.63 Hz, a signal-to-noise dynamic range of 77dB for 500-Hz bandwidth and 74 dB for 1-kHz bandwidth based on 50 g, and a maximum clock noise of 1.562 mV. The die size of the ASIC is 2.8 mm 2.3 mm using a standard 0.6- mum CMOS technology.

소형화된 1.6 GHz 단일 채널 도플러 센서를 이용한 실시간 호흡 및 심장 박동 감지기

본 논문에서는 사람의 생체 신호를 감지하기 위해 1.6 GHz 단일 채널 도플러 센서와 아날로그 및 디지털 신호 처리부로 구성되어 있는 실시간 호흡 및 심장 박동 감지기를 개발하였다. 도플러 센서의 RF Front End는 발진기, 믹서, 저잡음 증폭기, 브랜치-라인 하이브리드, 그리고 패치 안테나로 구성되어 있다. 센서에 사용된 브랜치-라인 하이브리드는 기존의 하이브리드에 비해 40 % 정도 크기를 줄이면서도 상당히 유사한 성능을 가지도록 인공 전송 선로(artificial transmission line)를 사용하였다. 아날로그 신호처리부는 2차 Sallen-Key 능동 필터를 사용하여 제작되었고 디지털 신호 처리부는 LabVIEW를 사용하여 컴퓨터상에서 구현되었다. 개발된 시스템은 최대 50 cm 거리에서 사람의 호흡과 심장 박동을 측정함으로써 성능을 검증하였다. This paper presents a real-time respiration and heartbeat detector comprised of a 1.6 GHz single-channel Doppler sensor and analog/digital signal processing block for remote vital sign detection. The RF front end of the Doppler sensor consists of an oscillator, mixer, low noise amplifier, branch-line hybrid and patch antenna. We apply artificial transmission lines(ATLs) to the branch-line hybrid, which leads to a size reduction of 40 % in the hybrid, while its performance is very comparable to that of a conventional hybrid. The analog signal conditioning block is implemented using second order Sallen-Key active filters and the digital signal processing block is realized with a LabVIEW program on a computer. The respiration and heartbeat detection is demonstrated at a distance of 50 cm using the developed system.

Design of a virtual instrument for water quality monitoring across the Internet

This article presents the design of a new distributed and multi-platform system for water quality monitoring, enhanced with powerful Internet capabilities. The measured variables are temperature, turbidity, pH, dissolved oxygen, and electrical conductivity. The signal-conditioning block has been simplified through the use of software routines for thermal compensation, hence, reducing the cost and dimensions. The system offers a wide variety of Internet capabilities, like e-mail alarm notifications, automatic storage of measured data in a remote machine via the FTP protocol, dynamic generation of HTML reports, real time graphs, and indicators visible from a remote web browser, etc. The whole system supports several types of computers, operating systems and communications hardware. Human presence near the geographic location of water is dramatically reduced, since the system automates the principal tasks of the classical water monitoring process.