scholarly journals A Microstrip Low-Pass Filter Design Using a Modified Radial Resonator in the Application of Aircraft Distance Measurement Equipment

Author(s):  
Hamid Radmanesh

In this paper, the application of microstrip technology is investigated in low-pass filters. A cascade microstrip low-pass filter with a sharp frequency response and a good cut-off bandwidth is presented using a modified radial resonator. The advantages of this proposed filter include minor losses in the transit band as well as the desired return. This filter design shows consistency when compared with the results of simulation and model performance. A comparison between the parameter values of this filter and previous structures indicates that it is desirable. The proposed filter can be used in modern communication systems such as aircraft distance measurement equipment (DME) antenna.

2018 ◽  
Vol 11 (5-6) ◽  
pp. 509-516 ◽  
Author(s):  
Dilip Kumar Choudhary ◽  
Mahmoud A. Abdalla ◽  
Raghvendra Kumar Chaudhary

AbstractA compact low-pass filter (LPF) with wide rejection band based on T-type circuit of an enhanced dual composite right-/left-handed (D-CRLH) resonator is presented in this paper. The resonator has only one cell with series and parallel tank circuit. The parallel LC tank circuit has been realized by an interdigital capacitor and one shorted finger, whereas its series LC tank circuit is realized by an air gap capacitance and a short circuit stub. The filter has wide rejection band bandwidth with three transmission zeros (TZs). The filter bandwidth and TZs frequencies are controlled by the D-CRLH element values. The results of the proposed filter demonstrate minimum insertion loss in passband, high roll-off rate, and good figure of merit. The measured results are in good agreement with the simulated results. The detailed filter design is discussed in terms of circuit modeling, dispersion analysis, and full-wave simulation. Finally, the filter size is compact (0.10 λg × 0.15 λg) at cut-off frequency.


Author(s):  
Darine Kaddour ◽  
Jean-Daniel Arnould ◽  
Philippe Ferrari

In this paper, a miniaturized bandpass filter for ultra-wide-band applications is proposed. It is based on the embedding of high-pass structures in a low-pass filter. A semi-lumped technology combining surface-mounted capacitors and transmission lines has been used. The filter design rules have been carried out. Furthermore, two filters having a 3-dB fractional bandwidth of 142 and 150%, centered at 0.77 and 1 GHz, respectively, have been realized for a proof of concept. Measured characteristics, in good agreement with simulations, show attractive properties of return loss (|S11| <−18 dB), insertion loss (<0.3 dB), and a maximum group delay and group delay variation of 2 and 1.3 ns, respectively. A distributed filter based on the same low-pass/high-pass approach has been also realized and measured for comparison. The size reduction reaches 85% for the semi-lumped filter, and its selectivity is improved with a shape factor of 1.3:1 instead of 1.5:1. The semi-lumped filter's drawback is related to a smaller rejection bandwidth compared to the distributed one. To improve the high-frequency stopband, an original technique for spurious responses suppression based on capacitively loaded stubs has been proposed. Even if the performances do not reach that obtained for the distributed approach, with this technique spurious responses are pushed until eight times the center frequency. A sensitivity study vs. critical parameters has also been carried out, showing the robustness of the design.


1965 ◽  
Vol AU-13 (5) ◽  
pp. 104-111 ◽  
Author(s):  
E. Foster

2011 ◽  
Vol 462-463 ◽  
pp. 124-129
Author(s):  
Shahrum Abdullah ◽  
Edisah Putra Teuku ◽  
Zaki Nuawi Mohd. ◽  
Mohd. Nopiah Zulkifli

This paper presents a comparison work between the filtering methods of fatigue strain loadings using the frequency spectrum and the wavelet transform (WT), in which a raw loading signal can be simplified for purpose of simulation. For this reason, the Fast Fourier Transform (FFT) and the Morlet wavelet algorithms were used in order to transform the vibrational fatigue time series into the frequency domain signal, leading to the observation of the frequency characteristics of the signal. To retain high amplitude cycles in the FFT algorithm, a low pass filter technique was applied to remove the high frequency signals with small amplitude that are non-damaging. The departure of high frequency information smoothed the low amplitude cycles at high frequency events in the fatigue signal. The Butterworth filter was selected as the most efficient filter design as it retained most of the fatigue damage and also had the capability to remove 30 % of the original low amplitude cycles. On the other hand, the Morlet wavelet managed to remove 64 % of the original 59 second signal. This wavelet filtering method removed 34 % more than the similar procedure applied through the FFT approach. Hence, this fatigue data summarising algorithm can be used for studying the durability characteristics of automotive components.


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