Embedding a reconfigurable band-pass/band-stop filter into an antenna

Author(s):  
M. E. Zamudio ◽  
Y. Tawk ◽  
C. G. Christodoulou ◽  
J. Costantine
Keyword(s):  
2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Ying Chen ◽  
Jianwei Cheng ◽  
Chaowu Liang

To date, little research has been carried out on the integration of switchable and diversified functionalities into a single metamaterial in the terahertz (THz) range. Here, a hybrid vanadium dioxide (VO2) metamaterial was designed with switchable properties of band-pass filter and band-stop filter in the frequency range of 0.3–1.6 THz. Simulations demonstrated that under TE polarization, the proposed system acted as band-stop filter with the center frequency of 0.95 THz when VO2 is in the insulating state. Upon the transformation of VO2 into the metallic state, the proposed system behaved as a band-pass filter with a transmittance of >80%. The physical mechanism of the band-pass/band-stop conversion was examined by analyzing the surface current distribution of the designed device. The switchable characteristics of this structure can enable its wide application in tunable THz functional components such as amplitude modulators, polarization control, and intelligent switches.


Sensors ◽  
2019 ◽  
Vol 19 (5) ◽  
pp. 1081 ◽  
Author(s):  
Eiyong Park ◽  
Minjae Lee ◽  
Sungjoon Lim

In this paper, we propose a switchable band-pass/band-stop filter using liquid metal alloy as a fluidic switch. The filter is designed based on the Chebyshev response and implemented using a three-stage quarter-wavelength resonant structure. The fluidic switch is realized by injecting eutectic gallium–indium (EGaIn) in the microfluidic stubs, engraved in the polydimethylsiloxane (PDMS) material. When the fluidic switch selects the short stub using a micro-pump and microprocessor for switching, the filter acts as a bandpass filter (BPF) with the short stubs. When the fluidic switch selects the open stub, the filter acts as the bandstop filter (BSF) with the open stubs. At the BPF mode, the center frequency is 2.5 GHz and the 1-dB bandwidth is 1.75–3.07 GHz. The insertion loss is 0.5-dB ± 0.4-dB. At the BSF mode, the 15-dB bandstop bandwidth is 2.4–2.65 GHz with 2.5 GHz center frequency.


1968 ◽  
Vol 11 (1) ◽  
pp. 63-76
Author(s):  
Donald C. Teas ◽  
Gretchen B. Henry

The distributions of instantaneous voltage amplitudes in the cochlear microphonic response recorded from a small segment along the basilar membrane are described by computing amplitude histograms. Comparisons are made between the distributions for noise and for those after the addition to the noise of successively stronger sinusoids. The amplitudes of the cochlear microphonic response to 5000 Hz low-pass noise are normally distributed in both Turn I and Turn III of the guinea pig’s cochlea. The spectral composition of the microphonic from Turn I and from Turn III resembles the output of band-pass filters set at about 4000 Hz, and about 500 Hz, respectively. The normal distribution of cochlear microphonic amplitudes for noise is systematically altered by increasing the strength of the added sinusoid. A decrease of three percent in the number of small amplitude events (±1 standard deviation) in the cochlear microphonic from Turn III is seen when the rms voltage of a 500 Hz sinusoid is at −18 dB re the rms voltage of the noise (at the earphone). When the rms of the sinusoid and noise are equal, the decrease in small voltages is about 25%, but there is also an increase in the number of large voltage amplitudes. Histograms were also computed for the output of an electronic filter with a pass-band similar to Turn III of the cochlea. Strong 500 Hz sinusoids showed a greater proportion of large amplitudes in the filter output than in CM III . The data are interpreted in terms of an anatomical substrate.


Author(s):  
K.R. Shankarkumar ◽  
Gokul Kumar

: Filtering is an important step in the field of image processing to suppress the required parts or to remove any artifacts present in it. There are different types of filters like low pass, high pass, Band pass, IIR, FIR and adaptive filtering etc.., in these filters adaptive filters is an important filter because it is used to remove the noisy signal and images. Least Mean Square filter is a type of an adaptive filtering which is used to remove the noises present in the medical images. The working of LMS is based on the minimization of the difference between the error images using a closed loop feedback. Therefore presented technique called as Q-CSKA. Here the CSKA performs its operation in stages which is based on the nucleus stage. In the traditional CSKA the nucleus stage is depend on the parallel prefix adder in this work it is replaced by the QCA adder. The QCA adder utilizes the less area compared to PPA and it can be realized in Nanometer range also. For multiplexers, And OR Invert, OR and Invert logic is used to reduce the area and delay. Due to these advantages of the QCA, AOI-OAI logic the proposed method outperformed the LMS implementation in area, power, and accuracy and delay, this based five type image noise of medical pictures related to the best technique is out comes. It helps to medicinal practitioner to resolve the symptoms of patient with ease.


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