Design of a Gm-C low pass filter with low cutoff frequency

Author(s):  
Haidong Liu ◽  
Xiaohong Peng ◽  
Wuchen Wu
2013 ◽  
Vol 562-565 ◽  
pp. 1132-1136
Author(s):  
Xiao Wei Liu ◽  
Jian Yang ◽  
Song Chen ◽  
Liang Liu ◽  
Rui Zhang ◽  
...  

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.


Author(s):  
Yahya Ahmed Alamri ◽  
Nik Rumzi Nik Idris ◽  
Ibrahim Mohd. Alsofyani ◽  
Tole Sutikno

<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>


Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5173 ◽  
Author(s):  
Jorge Pérez-Bailón ◽  
Belén Calvo ◽  
Nicolás Medrano

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.


2014 ◽  
Vol 609-610 ◽  
pp. 1072-1076
Author(s):  
Qiu Ye Lv ◽  
Chong He ◽  
Wen Jie Fan ◽  
Yu Feng Zhang ◽  
Xiao Wei Liu

In this Paper, a 4th-Order Low-Pass Gm-C Filter is Presented. for the Design of Operational Tranconductance Amplifier(OTA), it Adopts the Techniques of Current Division and Current Cancellation. these Techniques can Help to Achieve a Low Transconductance Value. for the Architecture of the 4th-Order Gm-C Filter, it Consists of Two Biquads. the Two Biquads are Cascade Connected. the Gm-C Low-Pass Filter has been Implemented under 0.5 μm CMOS Process Model. the Final Simulation Results Show the Cutoff Frequency of the Filter is 100Hz and the Stop-Band Attenuation is Larger than 60dB. the Power Consumption is Lower than 1mW and the Total Harmonic Distortion(THD) is -55dB.


2012 ◽  
Vol 591-593 ◽  
pp. 2152-2156 ◽  
Author(s):  
Shao Kun Cai ◽  
Kai Dong Zhang ◽  
Mei Ping Wu ◽  
Yang Ming Huang

Combining with the error model of strapdown airborne scalar gravimetry, the paper analyses the natural motions of the aircraft, and then discusses how those natural motions of the aircraft influence the airborne scalar gravimetry. The spectra characteristic of measurement errors of the strapdown airborne scalar gravimetry can be obtained, and its relation with natural motions of the aircraft is demonstrated. As a result, we can determine the cutoff frequency of low-pass filter through the characteristic of the natural motions of the aircraft, the cutoff frequency is very important for acceleration extraction from the strapdown airborne scalar gravimeter.


Author(s):  
Badr Nasiri ◽  
Ahmed Errkik ◽  
Jamal Zbitou ◽  
Abdelali Tajmouati ◽  
Larbi El Abdellaoui ◽  
...  

In this work, a novel design of a Microstrip Low-pass filter based on metamaterial square split ring resonators (SRRs) is proposed. The SRRs has been added to obtain a reduced size and high performances. The filter is designed on an FR-4 substrate having a thickness of 1.6mm, a dielectric constant of 4.4 and loss tangent of 0.025. The proposed low-pass filter is characterized by a cutoff frequency of 2.4 GHz and an attenuation level below than -20dB in the stopband. The LPF is designed, simulated and optimized by using two electromagnetic solvers CST microwave studio and ADS. The computed results obtained by both solvers are in good agreement. The total surface area of the proposed circuit is 18x18mm2 excluding the feed line, its size is miniaturized by 40% compared to the conventional filter. The experimental results illustrate that the filter achieves very good electrical performances in the passband with a low insertion loss of 0.2 dB. Moreover, a suppression level can reach more than 35 dB in the rejected band.


2019 ◽  
Vol 8 (2) ◽  
pp. 382-388
Author(s):  
Khairil Anuar Khairi ◽  
Mohd Faizal Jamlos ◽  
Surentiran Padmanathan ◽  
Mohd Aminudin Jamlos ◽  
Muammar Mohamad Isa

The paper involved with the design, simulation and fabrication of 6th order elliptical-based Surface Mount Device (SMD) LPF with cutoff frequency at 700 MHz. Fabricated LPF is consisted of four PCB layers which components of SMD are soldered on the top layer. Another three layers is for grounding and shielding, power supply and grounding void. The four layers is crucial to avoid interference between components. The research has find out that the momentum simulation is definitely required to improve the signals response compared to a normal simulation by ADS software. The comparison between momentum simulated versus measured and normal simulated versus measured is 0.2 dB and 29 dB correspondingly. Such huge difference leads to conclusion that momentum simulation is saving time without having much struggles and efforts to get optimum readings. The Proposed SMD LPF has a very low insertion loss of 0.965dB with a transition region of 195 MHz which is good steepness to avoid any image frequency.


Sign in / Sign up

Export Citation Format

Share Document