Pub Date : 2014-05-26DOI: 10.1109/LASCAS.2014.6820254
G. F. Santillan-Quinonez, C. Galup-Montoro
In this paper we show that silicon split-contact magnetoresistors with geometric dimensions of the order of the Debye length (LD) can have much higher sensitivities than the usual devices with much larger length and width than LD. Numerical simulations carried out with Comsol Multiphysics show that silicon n-type magnetoresistors with dimensions of the order of LD can have magnetic sensitivity as high as 60%/T which is ten times higher than usual sensitivities.
{"title":"High-sensitivity split-contact magnetoresistors on lightly doped silicon substrates","authors":"G. F. Santillan-Quinonez, C. Galup-Montoro","doi":"10.1109/LASCAS.2014.6820254","DOIUrl":"https://doi.org/10.1109/LASCAS.2014.6820254","url":null,"abstract":"In this paper we show that silicon split-contact magnetoresistors with geometric dimensions of the order of the Debye length (LD) can have much higher sensitivities than the usual devices with much larger length and width than LD. Numerical simulations carried out with Comsol Multiphysics show that silicon n-type magnetoresistors with dimensions of the order of LD can have magnetic sensitivity as high as 60%/T which is ten times higher than usual sensitivities.","PeriodicalId":235336,"journal":{"name":"2014 IEEE 5th Latin American Symposium on Circuits and Systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114683278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-05-26DOI: 10.1109/LASCAS.2014.6820271
D. A. Calvillo-Cortes, L. D. Vreede
This paper analyses the pure- and mixed-mode operation of class-B outphasing amplifiers and provides the analytical expressions for the drive profiles, when assuming ideal devices. In pure-mode operation, output power is controlled by phase modulation only. In mixed-mode operation, amplitude control replaces phase control at the deep back-off power levels to save driving power and hence improve efficiency. Envelope simulations using a 10.6 dB PAR W-CDMA signal verify the analysis of an ideal class-B outphasing amplifier model with only 10 dB of transistor's power gain. In mixed-mode operation, they predict up to 65% of average total-efficiency which is 7%-points higher than an equivalent asymmetrical (1:3) Doherty amplifier.
本文分析了b类同相放大器纯模式和混合模式的工作情况，给出了在假设理想器件的情况下驱动曲线的解析表达式。在纯模式工作时，输出功率仅由相位调制控制。在混合模式操作中，在深度回退功率电平上，幅度控制取代相位控制，节省驱动功率，从而提高效率。采用10.6 dB PAR的W-CDMA信号进行包络仿真，验证了理想的b类共相放大器模型的分析，该模型的晶体管功率增益仅为10 dB。在混合模式操作中，他们预测平均总效率高达65%，比同等不对称(1:3)Doherty放大器高出7%。
{"title":"Analysis of pure- and mixed-mode class-B outphasing amplifiers","authors":"D. A. Calvillo-Cortes, L. D. Vreede","doi":"10.1109/LASCAS.2014.6820271","DOIUrl":"https://doi.org/10.1109/LASCAS.2014.6820271","url":null,"abstract":"This paper analyses the pure- and mixed-mode operation of class-B outphasing amplifiers and provides the analytical expressions for the drive profiles, when assuming ideal devices. In pure-mode operation, output power is controlled by phase modulation only. In mixed-mode operation, amplitude control replaces phase control at the deep back-off power levels to save driving power and hence improve efficiency. Envelope simulations using a 10.6 dB PAR W-CDMA signal verify the analysis of an ideal class-B outphasing amplifier model with only 10 dB of transistor's power gain. In mixed-mode operation, they predict up to 65% of average total-efficiency which is 7%-points higher than an equivalent asymmetrical (1:3) Doherty amplifier.","PeriodicalId":235336,"journal":{"name":"2014 IEEE 5th Latin American Symposium on Circuits and Systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114687672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-05-26DOI: 10.1109/LASCAS.2014.6820263
M. B. Machado, M. C. Schneider, C. Galup-Montoro
This paper presents a fully integrated enhanced swing Colpitts oscillator that operates from supply voltages below 4kT/q. Design equations considering the oscillation frequency and start-up conditions required for operation of the Colpitts oscillator are derived. The oscillator was built with a zero-VT transistor, due to its high drive capability at low voltages. Measurement results obtained for a prototype integrated in the IBM 130 nm technology demonstrated the operation of the oscillator with 86 mV of supply voltage.
{"title":"Design of a fully integrated colpitts oscillator operating at VDD below 4kT/q","authors":"M. B. Machado, M. C. Schneider, C. Galup-Montoro","doi":"10.1109/LASCAS.2014.6820263","DOIUrl":"https://doi.org/10.1109/LASCAS.2014.6820263","url":null,"abstract":"This paper presents a fully integrated enhanced swing Colpitts oscillator that operates from supply voltages below 4kT/q. Design equations considering the oscillation frequency and start-up conditions required for operation of the Colpitts oscillator are derived. The oscillator was built with a zero-VT transistor, due to its high drive capability at low voltages. Measurement results obtained for a prototype integrated in the IBM 130 nm technology demonstrated the operation of the oscillator with 86 mV of supply voltage.","PeriodicalId":235336,"journal":{"name":"2014 IEEE 5th Latin American Symposium on Circuits and Systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114902773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-05-26DOI: 10.1109/LASCAS.2014.6820261
O. F. Siebel, J. G. Pereira, M. C. Schneider, C. Galup-Montoro
In this paper we detail the development of a new in vivo MOSFET dosimeter built on the CD4007, a popular off-the-shelf CMOS circuit. The dosimeter, which is aimed at radiotherapy applications, combines a simple and accurate readout procedure with a small, low-cost and cable-free sensor. The linearity (97.5%) and radiation sensitivity (6.8 mV/Gy) of this dosimeter were tested using X-ray (6 MV).
{"title":"A MOSFET dosimeter built on an off-the-shelf component for in vivo radiotherapy applications","authors":"O. F. Siebel, J. G. Pereira, M. C. Schneider, C. Galup-Montoro","doi":"10.1109/LASCAS.2014.6820261","DOIUrl":"https://doi.org/10.1109/LASCAS.2014.6820261","url":null,"abstract":"In this paper we detail the development of a new in vivo MOSFET dosimeter built on the CD4007, a popular off-the-shelf CMOS circuit. The dosimeter, which is aimed at radiotherapy applications, combines a simple and accurate readout procedure with a small, low-cost and cable-free sensor. The linearity (97.5%) and radiation sensitivity (6.8 mV/Gy) of this dosimeter were tested using X-ray (6 MV).","PeriodicalId":235336,"journal":{"name":"2014 IEEE 5th Latin American Symposium on Circuits and Systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130771836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-05-26DOI: 10.1109/LASCAS.2014.6820274
A. Queiroz
This work discusses some structures of electrostatic generators that can be used for energy harvesting from mechanical vibrations or rotating movement, that do not require any active control circuit for their operation. The structures use an unstable generator to bias another generator, or just variable capacitors, which form the main generator. Their action is similar to electric generators based on electrets.
{"title":"Electrostatic energy harvesting without active control circuits","authors":"A. Queiroz","doi":"10.1109/LASCAS.2014.6820274","DOIUrl":"https://doi.org/10.1109/LASCAS.2014.6820274","url":null,"abstract":"This work discusses some structures of electrostatic generators that can be used for energy harvesting from mechanical vibrations or rotating movement, that do not require any active control circuit for their operation. The structures use an unstable generator to bias another generator, or just variable capacitors, which form the main generator. Their action is similar to electric generators based on electrets.","PeriodicalId":235336,"journal":{"name":"2014 IEEE 5th Latin American Symposium on Circuits and Systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128833218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-05-26DOI: 10.1109/LASCAS.2014.6820260
Gabriel Balota, Mário Saldanha, G. Sanchez, B. Zatt, M. Porto, L. Agostini
This paper presents an overview and a quality analysis about the 3D-High Efficiency Video Coding (3D-HEVC) emergent video coding standard. The current coding structure and the main features introduced in 3D-HEVC is presented and compared to High Efficiency Video Coding (HEVC) standard. Besides, this paper shows a quality analysis comparison between Multiview Video Coding (MVC) standard and 3D-HEVC emergent standard, using the 3D Common Test Conditions (CTC). Through software evaluations, it is possible to notice that 3D-HEVC achieves a 51.8% coding efficiency gain in average when compared to MVC. These results represent an advance in 3D video coding, since 3D-HEVC emergent standard is able to almost duplicate the coding efficiency, achieving a bit rate saving of almost 50% for all the evaluated test video sequences.
本文对3d -高效视频编码(3D-HEVC)紧急视频编码标准进行了概述和质量分析。介绍了目前3D-HEVC的编码结构和主要特点，并与HEVC (High Efficiency Video coding)标准进行了比较。此外，本文还利用3D通用测试条件(CTC)对多视图视频编码(MVC)标准与3D- hevc紧急标准进行了质量分析比较。通过软件评估，可以注意到3D-HEVC相比MVC平均实现了51.8%的编码效率提升。这些结果代表了3D视频编码的进步，因为3D- hevc紧急标准几乎能够复制编码效率，在所有评估的测试视频序列中实现近50%的比特率节省。
{"title":"Overview and quality analysis in 3D-HEVC emergent video coding standard","authors":"Gabriel Balota, Mário Saldanha, G. Sanchez, B. Zatt, M. Porto, L. Agostini","doi":"10.1109/LASCAS.2014.6820260","DOIUrl":"https://doi.org/10.1109/LASCAS.2014.6820260","url":null,"abstract":"This paper presents an overview and a quality analysis about the 3D-High Efficiency Video Coding (3D-HEVC) emergent video coding standard. The current coding structure and the main features introduced in 3D-HEVC is presented and compared to High Efficiency Video Coding (HEVC) standard. Besides, this paper shows a quality analysis comparison between Multiview Video Coding (MVC) standard and 3D-HEVC emergent standard, using the 3D Common Test Conditions (CTC). Through software evaluations, it is possible to notice that 3D-HEVC achieves a 51.8% coding efficiency gain in average when compared to MVC. These results represent an advance in 3D video coding, since 3D-HEVC emergent standard is able to almost duplicate the coding efficiency, achieving a bit rate saving of almost 50% for all the evaluated test video sequences.","PeriodicalId":235336,"journal":{"name":"2014 IEEE 5th Latin American Symposium on Circuits and Systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123380116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-05-26DOI: 10.1109/LASCAS.2014.6820256
Andres Amaya, G. Espinosa, R. Villamizar
In this paper the design of a very low-voltage current mirror with an enhanced output resistance is presented. The mirror is designed using transistors in weak-inversion region, which allows operating with reduced supply voltage. With the use of multiple feedback loops, parameters such as minimum output voltage and output resistance are kept constant with respect to supply voltage, temperature and fabrication process variations (PVT variations). The mirror is biased at 0.5 V and is designed in a standard 0.18 μm technology. As a result, the circuit needs only 60 mV and 80 mV to saturate for NMOS and PMOS implementations respectively, with a maximum variation of 10 mV for all process corners and temperatures between -40 °C and 120 °C, and supply voltages between 0.45 V and 0.55 V. Finally, the mirror was used in a one-stage fully-differential OTA, for which a gain of 75 dB was achieved.
{"title":"A robust to PVT variations low-voltage low-power current mirror","authors":"Andres Amaya, G. Espinosa, R. Villamizar","doi":"10.1109/LASCAS.2014.6820256","DOIUrl":"https://doi.org/10.1109/LASCAS.2014.6820256","url":null,"abstract":"In this paper the design of a very low-voltage current mirror with an enhanced output resistance is presented. The mirror is designed using transistors in weak-inversion region, which allows operating with reduced supply voltage. With the use of multiple feedback loops, parameters such as minimum output voltage and output resistance are kept constant with respect to supply voltage, temperature and fabrication process variations (PVT variations). The mirror is biased at 0.5 V and is designed in a standard 0.18 μm technology. As a result, the circuit needs only 60 mV and 80 mV to saturate for NMOS and PMOS implementations respectively, with a maximum variation of 10 mV for all process corners and temperatures between -40 °C and 120 °C, and supply voltages between 0.45 V and 0.55 V. Finally, the mirror was used in a one-stage fully-differential OTA, for which a gain of 75 dB was achieved.","PeriodicalId":235336,"journal":{"name":"2014 IEEE 5th Latin American Symposium on Circuits and Systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134162906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-05-26DOI: 10.1109/LASCAS.2014.6820292
M. Nuño-Maganda, Y. Hernández-Mier, C. Torres-Huitzil, Josue Jimenez-Arteaga
Commonly, in the citrus industry in Mexico, fruit grading is performed by humans through visual inspection. Manual inspection implies several problems in maintaining grading consistency and sorting uniformity. Citrus classification is normally achieved based on external visible criteria, such as size, shape and color. This problem has been addressed using computer vision algorithms, but an automatic grading machine based on computer vision usually requires large computational resources in order to perform the classification due to the complexity of the computer vision operators. This paper describes an embedded color-based citrus selection system implemented on a field programmable gate array (FPGA) device. Experimental results show that the proposed hardware architecture is able to process 720p color images at 30 fps. The proposed architecture was validated on a Spartan-6 FPGA and the hardware resource utilization is reported.
{"title":"FPGA-based real-time citrus classification system","authors":"M. Nuño-Maganda, Y. Hernández-Mier, C. Torres-Huitzil, Josue Jimenez-Arteaga","doi":"10.1109/LASCAS.2014.6820292","DOIUrl":"https://doi.org/10.1109/LASCAS.2014.6820292","url":null,"abstract":"Commonly, in the citrus industry in Mexico, fruit grading is performed by humans through visual inspection. Manual inspection implies several problems in maintaining grading consistency and sorting uniformity. Citrus classification is normally achieved based on external visible criteria, such as size, shape and color. This problem has been addressed using computer vision algorithms, but an automatic grading machine based on computer vision usually requires large computational resources in order to perform the classification due to the complexity of the computer vision operators. This paper describes an embedded color-based citrus selection system implemented on a field programmable gate array (FPGA) device. Experimental results show that the proposed hardware architecture is able to process 720p color images at 30 fps. The proposed architecture was validated on a Spartan-6 FPGA and the hardware resource utilization is reported.","PeriodicalId":235336,"journal":{"name":"2014 IEEE 5th Latin American Symposium on Circuits and Systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115479238","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-05-26DOI: 10.1109/LASCAS.2014.6820288
Joaquin Aldunate, Carlos Feres, S. Vlahoyiannatos, C. Oberli, Jean-Paul de Villers-Grandchamps, M. Guarini
There are applications that require long-range, low data rate and low power consumption communications that could be implemented with wireless sensor networks equipped with multiple antennas. We are implementing a transceiver for that purpose. The transceiver requires a specific reconstruction filter which isn't commercially available for our target technology, XFAB XH018. An integrated active DAC reconstruction filter was designed and implemented on the target technology using Synopsys design tools. This document present the design, implementation and testing of the reconstruction filter. The filter achieved the design requirements.
{"title":"A DAC reconstruction filter for narrowband long distance Communications","authors":"Joaquin Aldunate, Carlos Feres, S. Vlahoyiannatos, C. Oberli, Jean-Paul de Villers-Grandchamps, M. Guarini","doi":"10.1109/LASCAS.2014.6820288","DOIUrl":"https://doi.org/10.1109/LASCAS.2014.6820288","url":null,"abstract":"There are applications that require long-range, low data rate and low power consumption communications that could be implemented with wireless sensor networks equipped with multiple antennas. We are implementing a transceiver for that purpose. The transceiver requires a specific reconstruction filter which isn't commercially available for our target technology, XFAB XH018. An integrated active DAC reconstruction filter was designed and implemented on the target technology using Synopsys design tools. This document present the design, implementation and testing of the reconstruction filter. The filter achieved the design requirements.","PeriodicalId":235336,"journal":{"name":"2014 IEEE 5th Latin American Symposium on Circuits and Systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126746754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-05-26DOI: 10.1109/LASCAS.2014.6820247
E. Torres-Rios, C. Saavedra
The analysis of the nonlinear charge bias dependence according to the input power, with respect to the intermodulation distortion (IMD) product for a GaN-HEMT, is presented. The results obtained from the analysis of the two-tone measurements, are used to determine the GaN-HEMT model deficiencies. An extrinsic non-linear capacitance element is added to improve the accuracy of the core compact model. The simplicity of the measurement procedure and data analysis, makes this a suitable methodology for a good non-linear characterization for GaN-HEMT. A comparison between simulated and experimental data is presented over a Lm = 08μm GaN-HEMT under different bias and input power conditions to validated the proposed model.
{"title":"A new compact nonlinear model improvement methodology for GaN-HEMT","authors":"E. Torres-Rios, C. Saavedra","doi":"10.1109/LASCAS.2014.6820247","DOIUrl":"https://doi.org/10.1109/LASCAS.2014.6820247","url":null,"abstract":"The analysis of the nonlinear charge bias dependence according to the input power, with respect to the intermodulation distortion (IMD) product for a GaN-HEMT, is presented. The results obtained from the analysis of the two-tone measurements, are used to determine the GaN-HEMT model deficiencies. An extrinsic non-linear capacitance element is added to improve the accuracy of the core compact model. The simplicity of the measurement procedure and data analysis, makes this a suitable methodology for a good non-linear characterization for GaN-HEMT. A comparison between simulated and experimental data is presented over a Lm = 08μm GaN-HEMT under different bias and input power conditions to validated the proposed model.","PeriodicalId":235336,"journal":{"name":"2014 IEEE 5th Latin American Symposium on Circuits and Systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117300058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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