scholarly journals A CMOS Low Pass Filter for SoC Lock-in-Based Measurement Devices

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5173 ◽  
Author(s):  
Jorge Pérez-Bailón ◽  
Belén Calvo ◽  
Nicolás Medrano
Keyword(s):  
Dynamic Range ◽  
Current Trend ◽  
Cutoff Frequency ◽  
Oxide Semiconductor ◽  
Constant Current ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Compact Size ◽  
Low Pass ◽  
Lock In

This paper presents a fully integrated Gm–C low pass filter (LPF) based on a current steering Gm reduction-tuning technique, specifically designed to operate as the output stage of a SoC lock-in amplifier. To validate this proposal, a first-order and a second-order single-ended topology were integrated into a 1.8 V to 0.18 µm CMOS (Complementary Metal-Oxide-Semiconductor) process, showing experimentally a tuneable cutoff frequency that spanned five orders of magnitude, from tens of mHz to kHz, with a constant current consumption (below 3 µA/pole), compact size (<0.0140 mm2/pole), and a dynamic range better than 70 dB. Compared to state-of-the-art solutions, the proposed approach exhibited very competitive performances while simultaneously fully satisfying the demanding requirements of on-chip portable measurement systems in terms of highly efficient area and power. This is of special relevance, taking into account the current trend towards multichannel instruments to process sensor arrays, as the total area and power consumption will be proportional to the number of channels.

scholarly journals A Low Pass Filter With sub-Hz Cutoff Frequencies for a Portable On-Chip Lock-in Microinstrument

2018 ◽  
Vol 6 ◽  
Author(s):  
Jorge Pérez Bailón ◽  
Belén Calvo ◽  
Nicolás Medrano
Keyword(s):  
Dynamic Range ◽  
Output Stage ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Fully Integrated ◽  
Cutoff Frequencies ◽  
Compact Size ◽  
Low Pass ◽  
On Chip ◽  
Lock In

This paper presents a first-order single-ended fully-integrated Low Pass Filter (LPF) tunable from 114 mHz to 2.5 kHz, designed to conform the output stage of a portable lock-in amplifier requiring fc = 0.5 Hz, 5 Hz cutoff frequencies. It achieves the two target fc over a -40 to 120 °C range with a power consumption of 2.7 μW at 1.8 V supply, compact size and dynamic range above 80 dB.

scholarly journals 0.5 V Fifth-Order Butterworth Low-Pass Filter Using Multiple-Input OTA for ECG Applications

Sensors ◽  
2020 ◽  
Vol 20 (24) ◽  
pp. 7343
Author(s):  
Montree Kumngern ◽  
Nattharinee Aupithak ◽  
Fabian Khateb ◽  
Tomasz Kulej
Keyword(s):  
Power Consumption ◽  
Dynamic Range ◽  
Oxide Semiconductor ◽  
Cmos Process ◽  
Subthreshold Region ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Multiple Input ◽  
Low Pass ◽  
Fifth Order

This paper presents a 0.5 V fifth-order Butterworth low-pass filter based on multiple-input operational transconductance amplifiers (OTA). The filter is designed for electrocardiogram (ECG) acquisition systems and operates in the subthreshold region with nano-watt power consumption. The used multiple-input technique simplifies the overall structure of the OTA and reduces the number of active elements needed to realize the filter. The filter was designed and simulated in the Cadence environment using a 0.18 µm Complementary Metal Oxide Semiconductor (CMOS) process from Taiwan Semiconductor Manufacturing Company (TSMC). Simulation results show that the filter has a bandwidth of 250 Hz, a power consumption of 34.65 nW, a dynamic range of 63.24 dB, attaining a figure-of-merit of 0.0191 pJ. The corner (process, voltage, temperature: PVT) and Monte Carlo (MC) analyses are included to prove the robustness of the filter.

scholarly journals Improvement in Cutoff Frequency of Microstrip Butterworth Low Pass Filter using DGS Technique

2019 ◽  
Vol 9 (2) ◽  
pp. 1121-1124
Keyword(s):  
Stop Band ◽  
Cutoff Frequency ◽  
Ground Surface ◽  
Pass Band ◽  
Defected Ground Structure ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Compact Size ◽  
Low Pass ◽  
Sharp Rejection

This paper presents the design, analysis and fabrication of Butterworth Low pass filter with sharp rejection response using defected ground surface technique. The work is carried out to design a low pass filter with cut-off frequency 2.5 GHz to achieved the broad frequency response; the first step is to make a rectangle of 10x10mm at ground surface and the equivalent circuit for the DGS, subsequently followed to consequent L-C parameters extraction using analysis of S parameters response (EM simulation). The designed Butterworth low pass filter is realized and optimized using DGS (Defected Ground Structure) to attain a compact size, satisfactory transition sharpness along with low insertion loss in pass band and wide rejection in the stop band. The fabricated device showed the good conformity with theoretical and VNA measured result.

scholarly journals Wideband Reconfigurable Integrated Low-Pass Filter for 5G Compatible Software Defined Radio Solutions

Electronics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 734
Author(s):  
Karolis Kiela ◽  
Marijan Jurgo ◽  
Vytautas Macaitis ◽  
Romualdas Navickas
Keyword(s):  
Software Defined Radio ◽  
Dynamic Range ◽  
Noise Figure ◽  
Harmonic Distortion ◽  
Cmos Process ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Filter Performance ◽  
Low Pass ◽  
Bandwidth Tuning

This article presents a wideband reconfigurable integrated low-pass filter (LPF) for 5G NR compatible software-defined radio (SDR) solutions. The filter uses Active-RC topology to achieve high linearity performance. Its bandwidth can be tuned from 2.5 MHz to 200 MHz, which corresponds to a tuning ratio of 92.8. The order of the filter can be changed between the 2nd, 4th, or 6th order; it has built-in process, voltage, and temperature (PVT) compensation with a tuning range of ±42%; and power management features for optimization of the filter performance across its entire range of bandwidth tuning. Across its entire order, bandwidth, and power configuration range, the filter achieves in-band input-referred third-order intercept point (IIP3) between 32.7 dBm and 45.8 dBm, spurious free dynamic range (SFDR) between 63.6 dB and 79.5 dB, 1 dB compression point (P1dB) between 9.9 dBm and 14.1 dBm, total harmonic distortion (THD) between −85.6 dB and −64.5 dB, noise figure (NF) between 25.9 dB and 31.8 dB and power dissipation between 1.19 mW and 73.4 mW. The LPF was designed and verified using 65 nm CMOS process; it occupies a 0.429 mm2 area of silicon and uses a 1.2 V supply.

Novel Low-Pass Microwave Filter Based on Rectangular Ring DGS

2013 ◽  
Vol 273 ◽  
pp. 371-374
Author(s):  
Bao Ping Li ◽  
Yan Liang Zhang
Keyword(s):  
Stop Band ◽  
Center Frequency ◽  
Pass Band ◽  
Band Pass Filter ◽  
Defected Ground Structure ◽  
Ground Structure ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Compact Size ◽  
Low Pass

Due to the frequency response periodicity of distributed transmission line, microstrip band-pass filter usually produces parasitic pass-band and outputs harmonics away from the center frequency of main pass-band. Based on the study of rectangular ring defected ground structure, a 5-order microstrip LPF(low-pass filter) was designed using the single-pole band-stop and slow-wave characteristics of the rectangular ring DGS(Defected Ground Structure) and SISS(Step-Impedance Shunt Stub) structure. Compared with traditional LPF, this LPF presents the advantages of compact size, low insertion loss, broad stop-band and high steep. It also validates the requirements of miniaturization and high performance for filters.

Design and Simulation of Switched Capacitor Filter for Speed Change Parameter Converter

2013 ◽  
Vol 562-565 ◽  
pp. 1132-1136
Author(s):  
Xiao Wei Liu ◽  
Jian Yang ◽  
Song Chen ◽  
Liang Liu ◽  
Rui Zhang ◽  
...  
Keyword(s):  
Stop Band ◽  
Cutoff Frequency ◽  
Rapid Change ◽  
Pass Band ◽  
Cmos Process ◽  
Switched Capacitor ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass ◽  
The Time Domain

In this paper, we design a high-order switched capacitor filter for rapid change parameter converter. This design uses a structure which consists of three biquads filter sub-units. The design is a 6th-order SC elliptic low-pass filter, and the sample frequency is 250 kHz. By the MATLAB Simulink simulation, the system can meet the design requirements in the time domain. In this paper, the 6th-order switched capacitor elliptic low-pass filter was implemented under 0.5 um CMOS process and simulated in Cadence. The final simulation results show that the pass-band cutoff frequency is 10 kHz, and the maximum pass-band ripple is about 0.106 dB. The stop-band cutoff frequency is 20 kHz, and the minimum stop-band attenuation is 74.78 dB.

Rapid Recovery of Wide-Bandwidth Photothermal Signals via Homodyne Photothermal Spectrometry: Theory and Methodology

1993 ◽  
Vol 47 (4) ◽  
pp. 489-500 ◽  
Author(s):  
J. F. Power ◽  
M. C. Prystay
Keyword(s):  
High Frequency ◽  
Low Cost ◽  
Signal Recovery ◽  
Wide Bandwidth ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Filter Output ◽  
Low Pass ◽  
Four Quadrant ◽  
Lock In

Homodyne photothermal spectrometry (HPS) is a very wide bandwidth signal recovery technique which uses many of the elements of lock-in detection at very low cost. The method uses a frequency sweep, with a high-frequency bandwidth of up to 10 MHz, to excite a linear photothermal system. The response sweep of the photothermal system is downshifted into a bandwidth of a few kilohertz by means of in-phase mixing with the excitation sweep with the use of a four-quadrant double-balanced mixer and a low-pass filter. Under conditions derived from theory, the filter output gives a good approximation to the real part of the photothermal system's frequency response, dispersed as a function of time. From a recording of this signal, the frequency and impulse response of the photothermal system are rapidly recovered at very high resolution. The method has been tested with the use of laser photopyroelectric effect spectrometry and provides an inexpensive, convenient method for the recovery of high-frequency photothermal signals.

Improved Stator Flux Estimation for Direct Torque Control of Induction Motor Drives

2016 ◽  
Vol 7 (4) ◽  
pp. 1049
Author(s):  
Yahya Ahmed Alamri ◽  
Nik Rumzi Nik Idris ◽  
Ibrahim Mohd. Alsofyani ◽  
Tole Sutikno
Keyword(s):  
Induction Motor ◽  
Cutoff Frequency ◽  
Direct Torque Control ◽  
Motor Drives ◽  
Torque Control ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass ◽  
Flux Estimation ◽  
Stator Flux

<p>Stator flux estimation using voltage model is basically the integration of the induced stator back electromotive force (emf) signal. In practical implementation the pure integration is replaced by a low pass filter to avoid the DC drift and saturation problems at the integrator output because of the initial condition error and the inevitable DC components in the back emf signal. However, the low pass filter introduces errors in the estimated stator flux which are significant at frequencies near or lower than the cutoff frequency. Also the DC components in the back emf signal are amplified at the low pass filter output by a factor equals to . Therefore, different integration algorithms have been proposed to improve the stator flux estimation at steady state and transient conditions. In this paper a new algorithm for stator flux estimation is proposed for direct torque control (DTC) of induction motor drives. The proposed algorithm is composed of a second order high pass filter and an integrator which can effectively eliminates the effect of the error initial condition and the DC components. The amplitude and phase errors compensation algorithm is selected such that the steady state frequency response amplitude and phase angle are equivalent to that of the pure integrator and the multiplication and division by stator frequency are avoided. Also the cutoff frequency selection is improved; even small value can filter out the DC components in the back emf signal. The simulation results show the improved performance of the induction motor direct torque control drive with the proposed stator flux estimation algorithm. The simulation results are verified by the experimental results.</p>

Weak Signal Detection System Based on Lock-in Amplifier Technology

2013 ◽  
Vol 389 ◽  
pp. 489-493
Author(s):  
Yong Lv ◽  
Chun Hui Niu ◽  
Yue Qiang Li ◽  
Qing Shan Chen ◽  
Xiao Ying Li ◽  
...  
Keyword(s):  
Signal Detection ◽  
Detection System ◽  
Signal To Noise Ratio ◽  
Weak Signal ◽  
Weak Signal Detection ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass ◽  
Phase Sensitive ◽  
Lock In

In order to detect the weak signal deeply buried in the noise, a weak signal detection system based on lock-in amplifier is proposed. The system includes the preamplifier circuit, active low pass filter circuit, AC amplifying circuit and phase sensitive demodulation circuit. Test results show that it can greatly increase the signal-to-noise ratio (SNR) up to 12.7db.

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