HF Voltage-Controllable Band-Pass Filter Based on Varactor

2014 ◽  
Vol 631-632 ◽  
pp. 327-332
Author(s):  
Sheng Qian Ma ◽  
Chang Rong Zhao ◽  
Yan Ping Ji
Keyword(s):  
Filter Design ◽  
Design Method ◽  
Center Frequency ◽  
Resonant Circuit ◽  
Band Pass Filter ◽  
Pass Filter ◽  
Junction Capacitance ◽  
Function Expression ◽  
Band Pass ◽  
And Function

Varactor to replace commonly variable capacitance is applied to the tuner. This paper presents the voltage-controllable band-pass filter design method. The filter constitutes of operational amplifier, resistors, varactor MV209 and parallel LC resonant circuit. Center frequency range of the band-pass filters is from 19MHz to 25MHz controlled with DC voltage. It derives the transfer function of the filter and function expression of junction capacitance with reverse voltage. The frequency response of filter simulation and experimental results are given. Key words: Varactor; Band-Pass Filter; Voltage-Controllable Filter; Junction Capacitance

The Design and Simulation of the Array Induction Logging Tools’ Signal Conditioning Circuit

2012 ◽  
Vol 241-244 ◽  
pp. 1010-1013
Author(s):  
Yao Hu ◽  
Hong Lu Hu ◽  
Ding Jin Huang
Keyword(s):  
Relative Error ◽  
Design Method ◽  
Center Frequency ◽  
Band Pass Filter ◽  
Pass Filter ◽  
Band Filter ◽  
Induction Logging ◽  
Band Pass ◽  
Two Stages ◽  
Signal Conditioning Circuit

Array induction logging tools (AILT) detects the stratum conductivity based on the principle of electromagnetic induction, as a result, the signal of the amplitude using the AILT is in microvolt level. The small-signal is always drowned by noise at high-temperature and high-pressure condition. In order to collect the weak signal accurately, we propose a design method of signal modulator circuits based on the principle of differential amplifier and active band-pass filter with second band limitless gain and multi-path negative feedback. First, make the induction signal obtained from the coil two stages amplification. Then Execute two-order band-pass filter to the enlarged signal. At last, process the filtered signal by the backward circuits. Simulating the circuits by Pspice16.3, The result of simulation indicated that the gain relative error of preamplifier is less than 1% and the center frequency relative error of band filter is less than 4%. These data suggest that the relative error of the design circuits is less than routine instrument by 5%. So the Simulation verifies the feasibility of the signal modulator circuit.

Narrowband Bandpass Microstrip Filter Design

2014 ◽  
Vol 945-949 ◽  
pp. 2338-2341
Author(s):  
Yang Li
Keyword(s):  
Filter Design ◽  
Narrow Band ◽  
Simulation Software ◽  
Center Frequency ◽  
Band Pass Filter ◽  
Pass Filter ◽  
Band Filter ◽  
Prototype Structure ◽  
Narrow Band Filter ◽  
Band Pass

This paper analyzes the basic theory of the microstrip narrow-band filter design and accomplishes the design of narrow band-pass filter whose center frequency is on L-band with the help of the Agilent ADS simulation software. The filter adopts Chebyshev’s prototype structure and consists of coupled microstrip line. Its fluctuation is less than 0.5dB and attenuation is less than 1.5dB between 1.9GHZ and 2.1GHZ .Its port Reflection coefficient less than-15dB and attenuation is greater than 20dB at 1.72GHZ and 2.3GHZ. Layout simulation meets the requirement of filter design.

scholarly journals Band pass filter comparison of Hairpin line and square open-loop resonator method for digital TV community

2021 ◽  
Vol 10 (1) ◽  
pp. 101-110
Author(s):  
Budi Prasetya ◽  
Yuyun Siti Rohmah ◽  
Dwi Andi Nurmantris ◽  
Sarah Mulyawati ◽  
Reza Dipayana
Keyword(s):  
Filter Design ◽  
Design Method ◽  
Digital Tv ◽  
Open Loop ◽  
Digital Television ◽  
Band Pass Filter ◽  
Pass Filter ◽  
Community Band ◽  
Band Pass ◽  
The Right

The selection of the right filter design method is a very important first step for a radio frequency engineer. This paper presents the comparison of two methods of band pass filter design using hairpin-line and square open-loop resonator. Both methods were applied to obtain filter designs that can work for broadcasting system in digital television community. Band pass filter was simulated using design software and fabricated using epoxy FR-4 substrate. The results of simulation and measurement shown return loss value at 27.3 dB for hairpin line band pass filter and 25.901 for square open-loop resonator band pass filter. Voltage standing wave ratio parameter values were 1.09 and 1.1067 for hairpin line and square open-loop band pass filter respectively. The insertion loss values for the Hairpin line band pass filter and square open-loop band pass filter were 0.9692 and near 0 dB, respectively. Fractional bandwidth, for hairpin line band pass filter, was 6.7% while for square open-loop band pass filter was 4.8%. Regarding the size, the dimension of square open-loop resonator was approximately five times larger than hairpin-line band pass filter. Based on the advantages of the hairpin line method, we recommend that researchers choose the filter for digital TV broadcasting.

scholarly journals Multilayer End Coupled Band Pass Filter using Low-Temperature Co-Fired Ceramic Technology for Broadband Fixed Wireless

2018 ◽  
Vol 10 (3) ◽  
pp. 980
Author(s):  
Zulkifli Ambak ◽  
Hizamel M. Hizan ◽  
Ahmad Ismat Abdul Rahim ◽  
Azmi Ibrahim ◽  
Mohd Zulfadli M. Yusoff ◽  
...  
Keyword(s):  
Low Temperature ◽  
Design Method ◽  
Ceramic Technology ◽  
Center Frequency ◽  
Band Pass Filter ◽  
Pass Filter ◽  
Three Samples ◽  
Band Pass ◽  
Fixed Wireless ◽  
Multilayer Substrate

This paper presents design approach for realizing multilayer End Coupled Bandpass Filter (ECBPF) using low temperature co-fired ceramic (LTCC) technology at TMRND's LTCC Lab. Design method for the ECBPF is based on the coupled-resonator filter which was realized in LTCC multilayer substrate and operating at the center frequency of 42GHz. Three samples of EC BPF have been designed, simulated, fabricated and investigated in terms of performance and structure size.This multilayer ECBPF were fabricated in the 8 layers LTCC Ferro A6S materials with dielectric constant of 5.8, loss tangent of 0.002 and metallization of gold. The measured insertion loss for ECBPF was 2.43dB and return loss was 22.81dB at the center frequency at 42GHz. The overall size of the fabricated filter was 6.0 mm x 2.5 mm x 0.77 mm.

Implementation of the Variable Center Frequency Band-Pass Filter Based on FPGA

2014 ◽  
Vol 1049-1050 ◽  
pp. 642-645
Author(s):  
Dan Hua Hu ◽  
Zhao Xiong Zeng ◽  
Jing Song Meng ◽  
Chang Hua Zhang
Keyword(s):  
Frequency Band ◽  
Digital Filter ◽  
Design Method ◽  
High Reliability ◽  
Low Cost ◽  
Center Frequency ◽  
Band Pass Filter ◽  
Pass Filter ◽  
Band Pass ◽  
Sample Rate

Digital band-pass filters play a very important role in instrument design. For some special applications, such as corrosion inspection of buried oil or gas pipeline, more than one band-pass filter with different center frequencies are needed to process different frequency signals. FPGA (Field-Programmable Gate Array) are widely used in these applications because of its high compute velocity and flexibility. For low cost and high reliability purposes, it is expected that one digital filter with a fixed configuration parameters can serve as multi different center frequency digital filter. In this paper a design method is proposed to realize two different center frequency band-pass filters which have the same filtering effect. Through analysis of design process for FIR band-pass filter, it’s easy to find that if the ratios (filter’ sample rate of input data to its cut-off frequency) of two filters keep equal, the normalized frequency will also equal. Thus according to this, two band-pass filters can have the same coefficients only if they have the same ratio of sample rate to cut-off frequency. This relationship is discussed here and MATLAB experiment is used to prove its effectiveness. This method is already used to design filters in pipeline current mapper instrument to inspect pipeline corrosion.

scholarly journals Wideband Band-Pass Filter Design Using Coupled Line Cross-Shaped Resonator

Electronics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 2173
Author(s):  
Dong-Sheng La ◽  
Xin Guan ◽  
Shuai-Ming Chen ◽  
Yu-Ying Li ◽  
Jing-Wei Guo
Keyword(s):  
Bandpass Filter ◽  
Filter Design ◽  
Design Method ◽  
Band Pass Filter ◽  
Coupled Line ◽  
Pass Filter ◽  
Transmission Zeros ◽  
Coupled Lines ◽  
Band Pass ◽  
Line Cross

In this paper, a wideband bandpass filter with a coupled line cross-shaped resonator (CLCSR) is proposed. The proposed bandpass filter is composed of two open-end parallel coupled lines, one short-end parallel coupled line, one branch microstrip line, and the parallel coupled line feed structure. With the use of the even and odd mode approach, the transmission zeros and transmission poles of the proposed bandpass filter are analyzed. The coupling coefficient of the parallel coupled line feed structure is big, so the distance between the parallel coupled line is too small to be processed. A three microstirp lines coupled structure is used to realize strong coupling and cross coupling. This structure also can reduce the return loss in passband and increase the out-of-band rejection. The transmission zeros can be adjusted easily by varying the lengths of the open-end parallel coupled line or the short-end parallel coupled line. The proposed bandpass filter is fabricated and measured. The simulated results agree well with the measured ones, which shows that the design method is valid.

A Reduced-Size Microstrip Four Poles Hairpin Band-Pass Filter with Multilayer Parallel-Coupled Line for Satellite Broadcasting

2020 ◽  
Author(s):  
Qazwan Abdullah Tarbosh ◽  
Nor Shahida Mohd Shah ◽  
Bishwajeet Pandey ◽  
Adeeb Salh ◽  
Nabil Farah ◽  
...  
Keyword(s):  
Reflection Coefficient ◽  
Bandpass Filter ◽  
Filter Design ◽  
Center Frequency ◽  
Design System ◽  
Band Pass Filter ◽  
Coupled Line ◽  
Pass Filter ◽  
Satellite Broadcasting ◽  
Band Pass

Recently, a multilayer structure is very imperative to minimize the size of planar microstrip filters. In the flexible design and incorporation of other microwave components, a multilayer band-pass filter provides another dimension. This paper, therefore, introduces a band-pass filter of 2.52-2.65 GHz for digital broadcast applications using parallel-coupled line (PCL) and multilayer(ML) hairpin resonator. The targeted four-pole resonator has a center frequency of 2.58 GHz with a bandwidth of 130 MHz. The hairpin-line offers compact filter design structures. The proposed configuration of the parallel-coupled line (PCL) resonator is used to design the ML band-pass filter. The FR4 substrate with a dielectric constant (εr) of 4.3 and 1.6 mm thickness was used. Comparison analysis between the simulated insertion loss and the reflection coefficient of substrates RO3003 and FR4 was performed to verify the efficiency of the proposed filter design. Simulation of PCL filter is accomplished using computer simulation technology (CST)and an advanced design system(ADS). The PCL bandpass filter was experimentally validated and good agreement between simulation and measured results were achieved showing a well-measured reflection coefficient. The simulated results of the ML bandpass filter show that the circuit performs well, and the filter size is significantly reduced.

Envelope Analysis Based on the Combination of Morlet Wavelet and Kurtogram

2012 ◽  
Vol 490-495 ◽  
pp. 305-308
Author(s):  
Yu Liang ◽  
Yu Guo ◽  
Chuan Hui Wu ◽  
Yan Gao
Keyword(s):  
Frequency Band ◽  
Filter Banks ◽  
Morlet Wavelet ◽  
Center Frequency ◽  
Band Pass Filter ◽  
Pass Filter ◽  
Filter Bandwidth ◽  
Envelope Analysis ◽  
Band Pass ◽  
Complex Morlet Wavelet

Envelope analysis based on the combination of complex Morlet wavelet and Kurtogram have advantages of automatic calculation of the center frequency and bandwidth of required band-pass filter. However, there are some drawbacks in the traditional algorithm, which include that the filter bandwidth is not -3dB bandwidth and the analysis frequency band covered by the filter-banks are inconsistent at different levels. A new algorithm is introduced in this paper. Through it, both optimal center frequency and bandwidth of band-pass filter in the envelop analysis can be obtained adaptively. Meanwhile, it ensures that the filters in the filter-banks are overlapped at the point of -3dB bandwidth and the consistency of frequency band that the filter-banks covered.

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