Preselect Filter Research Articles

A multicriteria assessment of food safety measures for a large dairy farm in hot weather conditions

Dairy farms are vulnerable to the impacts of climate change through the alteration of raw milk quality and pressure on animal health. Measures in dairy farms are necessary to reduce microbiological risks that may impact animal health and may be passed on to humans through the consumption of contaminated dairy products. However, these additional controls should incur lower environmental impact, have a low cost of implementation, minimal impact on milk property, and sufficient effectiveness to control risks. This study selected a dairy farm located under hot weather conditions to demonstrate how these challenges may be considered. Our objective was to present how a multi-criteria decision analysis (MCDA) could be used to select the appropriate mitigation strategy for this farm among fifteen potential food safety measures.The MCDA framework brought together ten criteria classified into four supra criteria: stakeholder acceptance, food safety effectiveness, environmental impact, and impact on milk properties. The relative performances of various food safety measures scored against the ten criteria were expressed either in qualitative or quantitative values. Ultimately, the outranking MCDA technique, PROMETHEE II, was used to rank the measures.This study ranked the selected four food safety measures, namely, sand bedding, chitosan supplementation, cooling mister operation, and phage spray, after a series of preselection filters. It was found that none of these dominated the others on the ten criteria. However, MCDA has allowed the determination of the best compromise among the selected measures. It was found that an increase in the frequency of changing the sand bedding ranked first, and an increase in the operation of cooling misters was ranked last.The study demonstrated the benefit of MCDA in combining criteria of different nature (stakeholder acceptance, food safety effectiveness, environmental impact, milk properties), values, and scales to prioritize food safety measures. The approach can be applied to other dairy farms eager to limit the impacts of climate change while guaranteeing food safety.

Improving the Performance of Direct-Conversion SDRs for Radiated Precompliance Measurements

In this letter, a highly linear front end to improve the performance of software-defined radio (SDRs) for radiated precompliance measurements is presented. In CISPR band C/D, the test receiver needs to fulfill stringent requirements for using the quasi-peak detector. Usually, an expensive preselection filter bank is necessary to make fully compliant measurements of broadband transients. Direct-conversion-based SDRs show a limited out-of-the-box performance for precompliance measurements caused by, e.g., harmonic mixing and saturation effects. With the use of a triple-balanced mixer, a highly linear upconversion stage is built, eliminating the need for a filter bank. The dynamic range (DR) requirements for the SDR are strongly reduced by a narrowband intermediate frequency filter, making CISPR 16-1-1 compliant measurements possible. The sensitivity of the front end is comparable to professional receivers on the market, although no low-noise amplifier is implemented. The performance is verified by continuous wave (CW) and transient signals according to CISPR norms. The broadband measurement results are compared with traditional characterizations of the DR using the compression level and the noise figure. It shows that assumptions on the RF-link budget for a compliant design can be made with CW measurements. Based on our results, the requirements for the SDR front end are derived.

Multiparametric MRI and auto-fixed volume of interest-based radiomics signature for clinically significant peripheral zone prostate cancer

ObjectivesTo create a radiomics approach based on multiparametric magnetic resonance imaging (mpMRI) features extracted from an auto-fixed volume of interest (VOI) that quantifies the phenotype of clinically significant (CS) peripheral zone (PZ) prostate cancer (PCa).MethodsThis study included 206 patients with 262 prospectively called mpMRI prostate imaging reporting and data system 3–5 PZ lesions. Gleason scores > 6 were defined as CS PCa. Features were extracted with an auto-fixed 12-mm spherical VOI placed around a pin point in each lesion. The value of dynamic contrast-enhanced imaging(DCE), multivariate feature selection and extreme gradient boosting (XGB) vs. univariate feature selection and random forest (RF), expert-based feature pre-selection, and the addition of image filters was investigated using the training (171 lesions) and test (91 lesions) datasets.ResultsThe best model with features from T2-weighted (T2-w) + diffusion-weighted imaging (DWI) + DCE had an area under the curve (AUC) of 0.870 (95% CI 0.980–0.754). Removal of DCE features decreased AUC to 0.816 (95% CI 0.920–0.710), although not significantly (p = 0.119). Multivariate and XGB outperformed univariate and RF (p = 0.028). Expert-based feature pre-selection and image filters had no significant contribution.ConclusionsThe phenotype of CS PZ PCa lesions can be quantified using a radiomics approach based on features extracted from T2-w + DWI using an auto-fixed VOI. Although DCE features improve diagnostic performance, this is not statistically significant. Multivariate feature selection and XGB should be preferred over univariate feature selection and RF. The developed model may be a valuable addition to traditional visual assessment in diagnosing CS PZ PCa.Key Points• T2-weighted and diffusion-weighted imaging features are essential components of a radiomics model for clinically significant prostate cancer; addition of dynamic contrast-enhanced imaging does not significantly improve diagnostic performance.• Multivariate feature selection and extreme gradient outperform univariate feature selection and random forest.• The developed radiomics model that extracts multiparametric MRI features with an auto-fixed volume of interest may be a valuable addition to visual assessment in diagnosing clinically significant prostate cancer.

Design and performance comparison of a novel high Q coaxial resonator filter and compact waveguide filter for millimeter wave payload applications

A novel high-performance high Q filter with ultra-wide spurious-free stopband and thermally stable performance is introduced using higher order mode of the coaxial resonator. The 7-pole Chebyshev and a 5-pole cross-coupled filter are designed at Ka-band to validate the concept. A compact cross-coupled waveguide filter is introduced with a different approach to realize cross-coupling makes the filter compact. The coaxial resonator and waveguide resonator filter have the same configuration, and their performances are compared at ambient and over the temperature. The high power analysis is done for both these filters to find their power handling capability. The high power performance of the coaxial resonator filter is superior, and it can handle 45.525 kW peak power. This filter is suitable to be used as pre-select filter in millimeter wave payloads as well as for high power filtering applications.

300 GHz帯チューナブルフィルタの設計

To solve increase of the mobile traffic, radio communication systems using millimeter wave band or terahertz wave band are required. Therefore an accurate spectrum analyzer is necessary in these bands. A tunable pre-selection filter is a key device in building such a spectrum analyzer. Hence, we proposed FPW (Fabry-Perot resonator inside Waveguide) filter for millimeter-wave band tunable filter. The FPW filter was realized widely tunable band and small size. However, this filter was not developed over 140 GHz yet. In this paper, we describe a design of 300 GHz band FPW filer and simulation results.

Frequency Tuning Range Expansion for the Millimeter‐Wave Band Tunable Filter

SUMMARYFor the realization of the smart community, the Internet of Things (IoT) and sensor technology in the millimeter‐wave band is necessary. The development of these technologies requires accurate spectrum analysis in the frequency domain over 100 GHz. A tunable preselection filter is a key device in building such a spectrum analyzer. In this paper, we propose use of a ridge waveguide to achieve frequency tuning over a wider bandwidth. In addition, we demonstrate an example design and prototype for a filter with a relative bandwidth of 38% (75 GHz to 110 GHz) and 32% (78.1 GHz to 107.5 GHz), respectively.

Novel Tunable Filter for Millimeter-Wave Spectrum Analyzer Over 100 GHz

Rapid progress in millimeter-wave wireless communication technologies requires accurate spectrum analysis in the frequency domain over 100 GHz. A tunable preselection filter is a key device in building such a spectrum analyzer. This paper proposes a new tunable filter as a preselector in the frequency range from 110 to 140 GHz. The filter was designed using a commercial electromagnetic simulator and two prototypes were evaluated. The first proved the tuning function in the working range but had a large insertion loss of . The second with various structural and manufacturing improvements achieved both tunability and insertion loss of <;10 dB.

Effect of spectrally aware tunable front ends on wireless communication systems

In this paper, the benefits of adaptive preselect filtering are investigated by analyzing mote-to-mote throughput in the presence of interference. In a city-wide deployment of a sensor network, of the 150 wireless sensor nodes deployed in our urban test system, five nodes were electrically “lost”. Surprisingly, the limiting factor was not the signal strength, but the neighboring cell towers that caused nearby interference. Therefore, we explored the effect of an adaptive front end to mitigate these nearby interferers. The sensor motes operated at a fixed band, the unlicenced band of 902 to 928 MHz, and did not have the frequency adaptability of future cognitive radios. However, the effect was demonstrative of the potential benefits of adaptive preselect filtering. The measured result shows substantial improvements over the fixed band system by even slight tuning of the bandwidth and/or the center frequency of the preselect filter. Experimentally and numerically, we show that both tuning in the filter bandwidth and/or center frequency can significantly improve the packet reception rate. Guidelines for achieving an optimized filtering technique are given to provide a broad understanding of how the adaptable preselect filtering can be utilized.

A tool to evaluate correspondence between extraction ion chromatographic peaks and peptide-spectrum matches in shotgun proteomics experiments.

Chromatographed peptide signals form the basis of further data processing that eventually results in functional information derived from data-dependent bottom-up proteomics assays. We seek to rank LC/MS parent ions by the quality of their extracted ion chromatograms. Ranked extracted ion chromatograms act as an intuitive physical/chemical preselection filter to improve the quality of MS/MS fragment scans submitted for database search. We identify more than 4900 proteins when considering detector shifts of less than 7 ppm. High quality parent ions for which the database search yields no hits become candidates for subsequent unrestricted analysis for PTMs. Following this rational approach, we prioritize identification of more than 5000 spectrum matches from modified peptides and confirmed the presence of acetylaldehyde-modified His/Lys. We present a logical workflow that scores data-dependent selected ion chromatograms and leverage information about semianalytical LC/LC dimension prior to MS. Our method can be successfully used to identify unexpected modifications in peptides with excellent chromatography characteristics, independent of fragmentation pattern and activation methods. We illustrate analysis of ion chromatograms detected in two different modes by RF linear ion trap and electrostatic field orbitrap.

A $2\times V_{\rm DD}$-Enabled Mobile-TV RF Front-End With TV-GSM Interoperability in 1-V 90-nm CMOS

A 2 × VDD-enabled mobile-TV RF front-end with TV-GSM interoperability is described. It is an on/off-chip codesign employing externally three customized UHF/VHF preselect filters, an RF switch, and a balun. The integrated part includes: 1) a cascode-cascade inverter-based low-noise amplifier that features a high gain-to-power efficiency; 2) a linearized C-2C attenuator using reliably-overdriven MOS switches; 3) an inductive-peaking feedforward path that evens out the passband variation; and 4) two cascode I/Q mixer drivers capable to drive passive mixers with small gain and bandwidth reduction. Gate-drain-source engineering and self-biased structures are the keys enabling performance optimization with low power and no reliability risk. Fabricated in a 90-nm CMOS process with 1-V thin-oxide devices, the RF front-end measures 68-dB rejection at GSM-900 uplink, 0.7-dB passband roll-off, 3.9-dB noise figure, and -5.5-dBm third-order intercept point at a maximum voltage gain of 26.2 dB. The core occupies 0.28 mm2 and draws 15 mW. The achieved power-performance metrics compares favorably with the prior state of the art.

Large Improvement in Image Rejection of Double-Quadrature Dual-Conversion Low-IF Architectures

The reasons for a degradation of image-rejection performance in double-quadrature-double-quadrature and single-quadrature-double-quadrature dual-conversion low-IF downconverters are fully discussed in this paper. Polyphase filters (PPFs) are inserted at proper positions to minimize the effects of device/signal mismatches, and thus improve the image rejection without calibration. Both a 0.35-μm SiGe heterojunction bipolar transistor 5.2-GHz double-quadrature-double-quadrature downconverter with an RF PPF and a 0.18-μm CMOS 2.2/4.8-GHz single-quadrature-double-quadrature downconverter with a switched-band low-noise amplifier (LNA) and a narrowband inter-stage PPF are demonstrated. Compared with our previous work, the 5.2-GHz downconverter achieves a 15-dB improvement in image-rejection ratio (IRR) of the first image signal (IRR <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> ) even without a pre-selection filter or LNA. Additionally, the dual-band downconverter has a 25-dB improvement in IRR of the second image signal (IRR <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) , which nearly reaches the theoretical limit of a four-stage PPF covering 20-40 MHz.

Mathematical Formulations of Signal Propagation in Ultra-Wideband Transceiver Systems under a UWB Channel Environment with an Extension of Frequency Offset Correction

This paper analyzes mathematically the crucial aspects of signal processing in a Multi-Band (MB) Orthogonal Frequency Division Multiplexing (OFDM) based system considering Ultra-Wideband (UWB) channel environment. In the process of analysis, it emphasizes the significant features of UWB receiver design in comparison with ‘conventional’ narrow-band system. The analysis shows that the high dispersive nature of a frequency selective UWB channel effects the design of different signal processing blocks like pre-select filter, low noise amplifier (LNA) and analog-to-digital (A/D) converter in the receiver front end. The characteristic functions of each of these stages are now dominated by the channel characteristics and it needs to be modified accordingly. This analysis is extended further with the study of frequency offset error and its correction. The unbiased Cramer Rao Lower Bound (CRLB) of estimation error is calculated and supported by computer simulation. The performance of an MB-OFDM system with frequency offset correction in terms of Bit-Error-Rate (BER) is also reported.

Passive second-order anti-aliasing filter for RF sampling based receivers

A second-order FIR anti-aliasing filter for RF sampling receivers is presented. The principle and circuit implementation are detailed for a GSM 900 receiver. The achieved alias rejection is sufficient to meet the specifications without any RF preselect filters.

Low-Loss Integrated-Waveguide Passive Circuits Using Liquid-Crystal Polymer System-on-Package (SOP) Technology for Millimeter-Wave Applications

In this paper, we show a low-loss integrated waveguide (IWG), microstrip line-to-IWG transition, IWG bandpass filter (BPF), and system-on-package (SOP) using a liquid-crystal polymer (LCP) substrate, which can be used toward SOP technology for millimeter-wave applications. The proposed IWG can be used as a low-loss millimeter-wave transmission line on this substrate. The measured insertion loss of the IWG is -0.12 dB/mm and the measured insertion loss of two microstrip line-to-IWG transitions is -0.14 dB at 60 GHz. The evaluated IWG filter is demonstrated as the pre-select filter for RF front-end modules at the millimeter-wave band. The fabricated three-pole BPF at a center frequency of 61.1 GHz has specifications: a 3-dB bandwidth of approximately 13.4% (~8.4 GHz), an insertion loss of -1.8 dB at the center frequency of 61.1 GHz, and a rejection of >15 dB over the passband. The proposed IWG can also be used as a low-loss millimeter-wave feed-through transition and interconnection between the monolithic microwave integrated circuit and the module instead of the vertical via structure. In terms of a SOP on LCP for millimeter-wave applications, the top face of the IWG does not have any electromagnetic effects, and a package lid can be attached to provide a hermetic sealing. These low-loss IWG circuits on LCP can easily be used in many millimeter-wave packaging applications

A cryogenic front end for CDMA and UMTS wireless base stations

The design and the laboratory performance of a cryogenic front end for CDMA and UMTS wireless base stations is described together with the results of a first field test at a CDMA base station in the region of Tangshan in China. The central elements of the cryogenic front ends are the cryocooler, the cryostat and the cryogenic platform mounted with up to 6 HTS pre-selection filters of high selectivity combined with the corresponding cryogenic low noise amplifiers of high dynamic range as well as the associated control electronics. Design and performance of the UMTS and CDMA filters are described and the characteristic parameters of the cryogenic low noise preamplifier are given. An analysis of the results of the first field test is discussed.

A 2.5-GHz low-power, high dynamic range, self-tuned Q-enhanced LC filter in SOI

Q-enhanced LC filter technology offers a promising approach to remove the off-chip preselect filter still required in current transceivers. However, reported designs fail to meet stringent system specifications such as dynamic range and noise figure for existing wireless standards. The complexity and inaccuracy of frequency and Q tuning have also prevented acceptance in industry applications. This paper presents a low-power and high-performance design targeted at Bluetooth in a silicon-on-isolator (SOI) CMOS process. Drawing 5 mA from a 3-V supply, it achieves 23-dB voltage gain (14-dB power gain), approximately 6-dB noise figure, and a 153-dB/spl middot/Hz 1-dB compression point dynamic range, when operating with a 70-MHz bandwidth at 2.5 GHz. A simplified approach to frequency and Q tuning is also demonstrated, making Q-enhanced LC filtering feasible in industry application for the first time.

GPS low noise amplifier with high immunity to wireless jamming signals and power control option

Abstract. A SiGe GPS low noise amplifier with power control option and high immunity to wireless jamming signals is presented. These novel features applied to Atmel’s ATR0610 GPS LNA allow significant power saving at the radio interface while meeting the out-of-band linearity requirements. The results show the noise figure less than 2.1 dB, including the embedded pre-select filter, and out-of-band IIP3 above +8 dBm in the frequency range between 1.8GHz and 2 GHz with 3mA current consumption. The GPS system performance shows GPS sensitivity below -141 dBm with 5 ms integration interval.

Synthesis of speech from pitch prototype waveforms by time-synchronous waveform interpolation

In a method of synthesizing voiced speech from pitch prototype waveforms by time-synchronous waveform interpolation (TSWI), one or more pitch prototypes is extracted from a speech signal or a residue signal. The extraction process is performed in such a way that the prototype has minimum energy at the boundary. Each prototype is circularly shifted so as to be time-synchronous with the original signal. A linear phase shift is applied to each extracted prototype relative to the previously extracted prototype so as to maximize the cross-correlation between successive extracted prototypes. A two-dimensional prototype-evolving surface is constructed by unsampling the prototypes to every sample point. The two-dimensional prototype-evolving surface is re-sampled to generate a one-dimensional, synthesized signal frame with sample points defined by piecewise continuous cubic phase contour functions computed from the pitch lags and the phase shifts added to the extracted prototypes. A pre-selection filter may be applied to determine whether to abandon the TSWI technique in favor of another algorithm for the current frame. A post-selection performance measure may be obtained and compared with a predetermined threshold to determine whether the TSWI algorithm is performing adequately.

Superconductors and cryogenics for future communication systems

In the framework of a German research program on superconductors and ceramics for future communication technology, efforts are undertaken to demonstrate the feasibility of cryogenic and high-temperature superconductor technology for applications in communication satellites and base transceiver stations (BTS's) for terrestrial mobile communication. For the receiver front end of C-band satellites, noise reduction filters as well as input-multiplexer channel filters have been developed. A three-channel output multiplexer was composed of dielectric hemisphere filters with elliptic response. Associated encapsulation and cooling issues for spaceborne systems were investigated and an in-orbit demonstration of the complete setup will be performed on the International Space Station. Activities toward applications in terrestrial mobile communication are focused on BTS cryogenic front ends with single preselect filters of superior selectivity, and on reconfigurable front ends allowing some electronically controlled change in the preselection frequency response. A first version of a demonstrator for a cryogenic BTS front end was developed.

A hybrid superconductive/semiconductive microwave receiver

A 6 GHz hybrid superconductive/semiconductive microwave receiver (HSSMR) has been developed. It consists of an HTS microstrip preselect filter, a cryogenic LNA, a commercially available off-the-shelf mixer, and a superconducting local oscillator (LO). The operating bandwidth is 500 MHz, which is centered at an RF frequency of 5.9 GHz and a corresponding IF frequency of 4.483 GHz. Downconversion is facilitated by a 10.383 GHz LO. The oscillator incorporates an HTS/sapphire resonator with a measured unloaded Q of 98100, at 77 K. The entire receiver is cooled to an operating temperature of 77 K. The measured performance is given for each of the components and for the overall receiver. The resultant receiver conversion gain is 27.5 dB and the associated noise figure is less than 0.7 dB.