Investigations on Three-Pole Microstrip Low-Pass Filters Incorporated with DGS and Fractals for Selectivity Improvement

Author(s):  
Ch. Murali Krishna ◽  
Sudipta Das ◽  
Chaitali Koley ◽  
B. T. P. Madhav

In this paper, an investigation on compact microstrip low-pass filters (MLPFs) with extremely perfect low-pass characteristics and improved out-band suppression has been carried out for the improvement of the selectivity parameter ([Formula: see text]). For this purpose, two different defected ground structures (DGSs) based on Moore fractals and Meander line have been designed and experimentally validated. The proposed third-order low-pass filter (LPF) configurations are designed and simulated using the High-Frequency Structure Simulator (HFSS). To validate the simulation models, the prototypes of the suggested low-pass filters are fabricated using Teflon (TM) substrate having a relative permittivity of 2.65 and a loss tangent of 0.001, and measured using the Vector Network Analyzer. The simulation and measurement results are in good agreement. The proposed filters occupy a compact size of [Formula: see text]. The selectivity parameter values for the proposed Moore fractals- and Meander line-modeled DGS-based LPFs are 425[Formula: see text]dB/GHz and 850[Formula: see text]dB/GHz, respectively. The proposed microstrip low-pass filters offer a significant improvement in the selectivity parameter, offering a maximum value of 850[Formula: see text]dB/GHz. The proposed filters exhibit a very high figure of merit (FOM), reporting 71,335 for Moore fractals-based LPF and 118,354 for the Meander line-based LPF. These proposed filters are suitable for advanced mobile phone services, [Formula: see text]-band radar, Global Positioning System, mobile, paging services, Wi-Fi, Bluetooth and wireless LAN.

2013 ◽  
Vol 273 ◽  
pp. 371-374
Author(s):  
Bao Ping Li ◽  
Yan Liang Zhang

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.


2012 ◽  
Vol 1 (4) ◽  
pp. 356
Author(s):  
Pavan Sharma ◽  
Veerendra Jadaun ◽  
Devesh Mahor ◽  
Atal Verma

The filter is required in all RF-communication techniques. Low Pass Filters play an important role in wireless power transmission systems. Transmitted and received signals have to be filtered at a certain frequency with a specific bandwidth. In this paper the design of filter is done in the ISM (Industrial, Scientific and Medical) band whose frequency lies between 1.55GHz- 3.99GHz. After getting the specifications required, we realized the filter structure with the help of CST-MW software.


2016 ◽  
Vol 59 (3) ◽  
pp. 528-541 ◽  
Author(s):  
Qaiser Jahan

AbstractIn this article, we give necessary and sufficient conditions on a function to be a low-pass filter on a local field K of positive characteristic associated with the scaling function for multiresolution analysis of L2(K). We use probability and martingale methods to provide such a characterization.


Author(s):  
A. G. Zinovev ◽  
I. A. Shestakov

A method for measuring the self-capacitance, inductance, loss resistance, and Q-factor of inductors as part of an LC low-pass filter at its operating frequency is presented. An example of the practical application of this method for measuring the equivalent pa-rameters of inductors and capacitors as part of a fifth-order Cauer low-pass filter using network analyzer.


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.


2013 ◽  
Vol 25 (10) ◽  
pp. 917-920 ◽  
Author(s):  
Ying Gao ◽  
Jian Hong Ke ◽  
John C. Cartledge ◽  
Kang Ping Zhong ◽  
Scott S.-H. Yam

2020 ◽  
Vol 8 (5) ◽  
pp. 1225-1229

This paper presents the design of a class of highly selective micro strip low pass filters. The proposed structure is considered for Stepped Impedance Low Pass Butterworth filter of order n=3 and n=5 with cut-off frequency 1.2 GHz and passband ripple of 3.01db [1]. The substrate FR4 having a dielectric constant 4.4 is considered for calculating the physical length of the micro strip low pass filter. The designing equation are solved using MATLAB Software and the results are analysed and compared using IE3D Simulator. The microwave filter is a building block that provides frequency selectivity in various microwave application like mobile, radar, satellite communication systems. The simulated results show the insertion loss and return loss of about -6.65 dB & - 55.49dB for N=3 and -7.23dB &-16.01 dB for N=5.Simulation has also been done for VSWR.


2018 ◽  
Vol 27 (03n04) ◽  
pp. 1840021 ◽  
Author(s):  
Shahed Enamul Quadir ◽  
John A. Chandy

Physical Unclonable Functions (PUFs) are probabilistic circuit primitives that extract randomness from the physical characteristics of a device. PUFs are easy and simple to implement and its random nature makes its behavior hard to predict and model. Most existing PUF designs are based on variation at the chip level and can not be implemented in a printed circuit board (PCB). Therefore, these PUFs can not be used to protect against counterfeit PCBs in a distributed supply chain. In this work, we propose a novel PUF design based on resistor and capacitor variations for low pass filters (LoPUF). We demonstrate the setup in a protoboard for different resistor-capacitor pairs (RC pairs) for reliable low pass filter PUF. Because of process variations, the voltage will be different at the same cut-off frequency for our proposed PUF. Finally, the output of the filter is connected to an inverter to measure the pulse width and best suitable pulses are used for ID generation based on our algorithm.


Author(s):  
A. G. Zinovyev ◽  
I. A. Shestakov

Harmonic filters of short-wave transmitters, tunable in the frequency range using discrete variable capacitors, are presented. A comparison of a harmonic filter based on tunable LC low-pass filters with inductive coupling between the filter inductors is carried out with a similar harmonic filter, each LC low-pass filter of which con-tains an additional capacitive coupling capacitor connected between the two filter links and significantly changed the parameters of the harmonic filter.


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