Detection of bioparticles is of great importance in electrophoresis, identification of biomass so... more Detection of bioparticles is of great importance in electrophoresis, identification of biomass sources, food and water safety, and other areas. It requires a proper model to describe bioparticles’ electromagnetic characteristics. A numerical study of Escherichia coli bacteria during their functional activity was carried out by using two different geometrical models for the cells that considered the bacteria as layered ellipsoids and layered spheres. It was concluded that during cell duplication, the change in the dielectric permittivity of the cell is high enough to be measured at radio frequencies of the order of 50 kHz. An experimental setup based on the capacitive Wheatstone bridge was designed to measure relative changes in permittivity during cell division. In this way, the theoretical model was validated by measuring the dielectric permittivity changes in a cell culture of Escherichia coli ATTC 8739 from WDCM 00012 Vitroids. The spheroidal model was confirmed to be more accurate.
The investigation of the electromagnetic properties of biological particles in microfluidic platf... more The investigation of the electromagnetic properties of biological particles in microfluidic platforms may enable wireless monitoring and interaction with functional activity of microorganisms. Of high relevance is the membrane potential as it is one of the most important parameters of living cells. In particular, the complex mechanisms of the cell’s membrane potential are comparable to the dynamics of bacteria membranes, providing a simplified platform for advancing the current techniques and knowledge of general bio-particle dynamics. In this work, we provide a theoretical analysis and experimental results on the microwave detection of bacteria on a microfluidic-based framework for sensing the membrane potential of bacteria. The results enable to further advance the state-of-the-art of electromagnetic bacteria sensing and microfluidic control, and their implication for measuring and interacting with the cell and its membrane potentials, which is of great importance for developing n...
A complet process of design and measurement of parabolic antennas, is presented. We have implemen... more A complet process of design and measurement of parabolic antennas, is presented. We have implemented a set of programs in order to design and analyze the different geometries of parabolic reflectors. The measurements are made on a near field cylindrical system. Finally the most recent studies on antenna metrology and the definition of a semicompact cylindrical field are shown.
The need for non-ionizing techniques for medical imaging applications has led to the use of micro... more The need for non-ionizing techniques for medical imaging applications has led to the use of microwave signals. Several systems have been introduced in recent years based on increasing the number of antennas and frequency bandwidth to obtain high resolution and good accuracy in locating objects. A novel microwave imaging system that reduces the number of required antennas for precise target location appropriate for medical applications is presented. The proposed system consists of four UWB extended gap ridge horn (EGRH) antennas covering the frequency band from 0.5 GHz to 1.5 GHz mounted on a cylindrical phantom that mimics the brain in an orthogonal set of two EGRH probes. This configuration has the ability to control both the longitudinal and transversal dimensions of the reconstructed target’s image, rather than controlling the spatial resolution, by increasing the frequency band that can be easily affected by medium losses. The system is tested numerically and experimentally by t...
In this paper, we present a cylindrical microwave imaging system based on a multi-frequency bi-fo... more In this paper, we present a cylindrical microwave imaging system based on a multi-frequency bi-focusing (MFBF) imaging technique using Extended Gap Ridge Horn antenna (EGRH) probe for medical applications. The proposed probe antenna is designed to operate between 0.5 GHz to 1 GHz and filled with a high permittivity material to have an impedance match to the human body. This system has been successfully simulated using CST Microwave studi
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
IEEE Transactions on Antennas and Propagation, 2010
A new kind of double-and single-arm cantilever type DC-contact RF MEMS actuators has been monolit... more A new kind of double-and single-arm cantilever type DC-contact RF MEMS actuators has been monolithically integrated with an antenna architecture to develop a frequency reconfigurable antenna. The design, microfabrication, and characterization of this "reconfigurable antenna (RA) annular slot" which was built on a microwave laminate TMM10i (= 9.8, tan = 0.002), are presented in this paper. By activating/deactivating the RF MEMS actuators, which are strategically located within the antenna geometry and microstrip feed line, the operating frequency band is changed. The RA annular slot has two reconfigurable frequencies of operation with center frequencies low =2.4 GHz and high = 5.2 GHz, compatible with IEEE 802.11 WLAN standards. The radiation and impedance characteristics of the antenna along with the RF performance of individual actuators are presented and discussed.
IEEE Antennas and Wireless Propagation Letters, 2014
The design, microfabrication, and characterization of a broadband patch antenna capable of coveri... more The design, microfabrication, and characterization of a broadband patch antenna capable of covering the entire IEEE 802.11ad (WiGig) frequency band (57-66 GHz) are presented in this letter. A conductor-backed (CB) coplanar waveguide (CPW)-fed loop slot couples the energy to the patch antenna, resulting in a broad bandwidth. The feed circuitry along with the loop is formed on a quartz substrate (at 60 GHz), on top of which an SU-8-based three-dimensional (3-D) structure with air cavities is microfabricated. The patch metallization is deposited on top of this 3-D structure. While the main role of the structure made out of SU-8 material is to provide a mechanical support for the patch metallization, the antenna takes advantage of the air cavities underneath, thus resulting in an antenna substrate with a very low loss. This, in turn, improves the overall antenna performances. The simulated and measured impedance characteristics agree well, showing % bandwidth. Also, the radiation pattern results demonstrate the integrity of radiation pattern with reasonably constant gain values (average dB) in the broadside direction over the entire WiGig band.
A MEMS reconfigurable antenna with beam steering capability and resonance frequency reconfigurabi... more A MEMS reconfigurable antenna with beam steering capability and resonance frequency reconfigurability is presented. The design is based in an interconnected patch grid structure and employs a hybrid geometry with different sized patches in a biclustered ...
Biomedical microwave imaging is a topic of continuous research for its potential in different are... more Biomedical microwave imaging is a topic of continuous research for its potential in different areas especially in breast cancer detection. In this paper, 3D UWB Magnitude-Combined tomographic algorithm is assessed for this recurrent application, but also for a more challenging one such as brain stroke detection. With the UWB Magnitude-Combined concept, the algorithm can take advantage of both the efficiency of Fourier Diffraction Theorem-based tomographic formulation and the robustness and image quality improvement provided by a multi-frequency combination.
An RFID-based wireless system to measure the evolution of the setting process of cement-based mat... more An RFID-based wireless system to measure the evolution of the setting process of cement-based materials is presented in this paper. The system consists of a wireless RFID temperature sensor that works embedded in concrete, and an external RFID reader that communicates with the embedded sensor to extract the temperature measurement conducted by the embedded sensor. Temperature time evolution is a well known proxy to monitor the setting process of concrete. The RFID sensor consisting of an UWB Bow Tie antenna with central frequency 868 MHz, matched to the EM4325 temperature chip through a T-match structure for embedded operation inside concrete is fully characterized. Results for measurements of the full set up conducted in a real-scenario are provided.
There is an increasing need for safe and simple techniques for sensing devices and prostheses imp... more There is an increasing need for safe and simple techniques for sensing devices and prostheses implanted inside the human body. Microwave wireless inspection may be an appropriate technique for it. The implanted device may have specific characteristics that allow to distinguish it from its environment. A new sensing technique based on the principle of differential resonance is proposed and its basic parameters are discussed. This technique allows to use the implant as a signal scattering device and to detect changes produced in the implant based on the corresponding change in its scattering signature. The technique is first tested with a canonic human phantom and then applied to a real in vivo clinical experiment to detect coronary stents implanted in swine animals.
Paradigmes Economia Productiva I Coneixement, 2008
Little vocation: Lack of appeal, difficulty to grasp the subject in secondary school and unattrac... more Little vocation: Lack of appeal, difficulty to grasp the subject in secondary school and unattractive salary perspectives and professional careers
Detection of bioparticles is of great importance in electrophoresis, identification of biomass so... more Detection of bioparticles is of great importance in electrophoresis, identification of biomass sources, food and water safety, and other areas. It requires a proper model to describe bioparticles’ electromagnetic characteristics. A numerical study of Escherichia coli bacteria during their functional activity was carried out by using two different geometrical models for the cells that considered the bacteria as layered ellipsoids and layered spheres. It was concluded that during cell duplication, the change in the dielectric permittivity of the cell is high enough to be measured at radio frequencies of the order of 50 kHz. An experimental setup based on the capacitive Wheatstone bridge was designed to measure relative changes in permittivity during cell division. In this way, the theoretical model was validated by measuring the dielectric permittivity changes in a cell culture of Escherichia coli ATTC 8739 from WDCM 00012 Vitroids. The spheroidal model was confirmed to be more accurate.
The investigation of the electromagnetic properties of biological particles in microfluidic platf... more The investigation of the electromagnetic properties of biological particles in microfluidic platforms may enable wireless monitoring and interaction with functional activity of microorganisms. Of high relevance is the membrane potential as it is one of the most important parameters of living cells. In particular, the complex mechanisms of the cell’s membrane potential are comparable to the dynamics of bacteria membranes, providing a simplified platform for advancing the current techniques and knowledge of general bio-particle dynamics. In this work, we provide a theoretical analysis and experimental results on the microwave detection of bacteria on a microfluidic-based framework for sensing the membrane potential of bacteria. The results enable to further advance the state-of-the-art of electromagnetic bacteria sensing and microfluidic control, and their implication for measuring and interacting with the cell and its membrane potentials, which is of great importance for developing n...
A complet process of design and measurement of parabolic antennas, is presented. We have implemen... more A complet process of design and measurement of parabolic antennas, is presented. We have implemented a set of programs in order to design and analyze the different geometries of parabolic reflectors. The measurements are made on a near field cylindrical system. Finally the most recent studies on antenna metrology and the definition of a semicompact cylindrical field are shown.
The need for non-ionizing techniques for medical imaging applications has led to the use of micro... more The need for non-ionizing techniques for medical imaging applications has led to the use of microwave signals. Several systems have been introduced in recent years based on increasing the number of antennas and frequency bandwidth to obtain high resolution and good accuracy in locating objects. A novel microwave imaging system that reduces the number of required antennas for precise target location appropriate for medical applications is presented. The proposed system consists of four UWB extended gap ridge horn (EGRH) antennas covering the frequency band from 0.5 GHz to 1.5 GHz mounted on a cylindrical phantom that mimics the brain in an orthogonal set of two EGRH probes. This configuration has the ability to control both the longitudinal and transversal dimensions of the reconstructed target’s image, rather than controlling the spatial resolution, by increasing the frequency band that can be easily affected by medium losses. The system is tested numerically and experimentally by t...
In this paper, we present a cylindrical microwave imaging system based on a multi-frequency bi-fo... more In this paper, we present a cylindrical microwave imaging system based on a multi-frequency bi-focusing (MFBF) imaging technique using Extended Gap Ridge Horn antenna (EGRH) probe for medical applications. The proposed probe antenna is designed to operate between 0.5 GHz to 1 GHz and filled with a high permittivity material to have an impedance match to the human body. This system has been successfully simulated using CST Microwave studi
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
IEEE Transactions on Antennas and Propagation, 2010
A new kind of double-and single-arm cantilever type DC-contact RF MEMS actuators has been monolit... more A new kind of double-and single-arm cantilever type DC-contact RF MEMS actuators has been monolithically integrated with an antenna architecture to develop a frequency reconfigurable antenna. The design, microfabrication, and characterization of this "reconfigurable antenna (RA) annular slot" which was built on a microwave laminate TMM10i (= 9.8, tan = 0.002), are presented in this paper. By activating/deactivating the RF MEMS actuators, which are strategically located within the antenna geometry and microstrip feed line, the operating frequency band is changed. The RA annular slot has two reconfigurable frequencies of operation with center frequencies low =2.4 GHz and high = 5.2 GHz, compatible with IEEE 802.11 WLAN standards. The radiation and impedance characteristics of the antenna along with the RF performance of individual actuators are presented and discussed.
IEEE Antennas and Wireless Propagation Letters, 2014
The design, microfabrication, and characterization of a broadband patch antenna capable of coveri... more The design, microfabrication, and characterization of a broadband patch antenna capable of covering the entire IEEE 802.11ad (WiGig) frequency band (57-66 GHz) are presented in this letter. A conductor-backed (CB) coplanar waveguide (CPW)-fed loop slot couples the energy to the patch antenna, resulting in a broad bandwidth. The feed circuitry along with the loop is formed on a quartz substrate (at 60 GHz), on top of which an SU-8-based three-dimensional (3-D) structure with air cavities is microfabricated. The patch metallization is deposited on top of this 3-D structure. While the main role of the structure made out of SU-8 material is to provide a mechanical support for the patch metallization, the antenna takes advantage of the air cavities underneath, thus resulting in an antenna substrate with a very low loss. This, in turn, improves the overall antenna performances. The simulated and measured impedance characteristics agree well, showing % bandwidth. Also, the radiation pattern results demonstrate the integrity of radiation pattern with reasonably constant gain values (average dB) in the broadside direction over the entire WiGig band.
A MEMS reconfigurable antenna with beam steering capability and resonance frequency reconfigurabi... more A MEMS reconfigurable antenna with beam steering capability and resonance frequency reconfigurability is presented. The design is based in an interconnected patch grid structure and employs a hybrid geometry with different sized patches in a biclustered ...
Biomedical microwave imaging is a topic of continuous research for its potential in different are... more Biomedical microwave imaging is a topic of continuous research for its potential in different areas especially in breast cancer detection. In this paper, 3D UWB Magnitude-Combined tomographic algorithm is assessed for this recurrent application, but also for a more challenging one such as brain stroke detection. With the UWB Magnitude-Combined concept, the algorithm can take advantage of both the efficiency of Fourier Diffraction Theorem-based tomographic formulation and the robustness and image quality improvement provided by a multi-frequency combination.
An RFID-based wireless system to measure the evolution of the setting process of cement-based mat... more An RFID-based wireless system to measure the evolution of the setting process of cement-based materials is presented in this paper. The system consists of a wireless RFID temperature sensor that works embedded in concrete, and an external RFID reader that communicates with the embedded sensor to extract the temperature measurement conducted by the embedded sensor. Temperature time evolution is a well known proxy to monitor the setting process of concrete. The RFID sensor consisting of an UWB Bow Tie antenna with central frequency 868 MHz, matched to the EM4325 temperature chip through a T-match structure for embedded operation inside concrete is fully characterized. Results for measurements of the full set up conducted in a real-scenario are provided.
There is an increasing need for safe and simple techniques for sensing devices and prostheses imp... more There is an increasing need for safe and simple techniques for sensing devices and prostheses implanted inside the human body. Microwave wireless inspection may be an appropriate technique for it. The implanted device may have specific characteristics that allow to distinguish it from its environment. A new sensing technique based on the principle of differential resonance is proposed and its basic parameters are discussed. This technique allows to use the implant as a signal scattering device and to detect changes produced in the implant based on the corresponding change in its scattering signature. The technique is first tested with a canonic human phantom and then applied to a real in vivo clinical experiment to detect coronary stents implanted in swine animals.
Paradigmes Economia Productiva I Coneixement, 2008
Little vocation: Lack of appeal, difficulty to grasp the subject in secondary school and unattrac... more Little vocation: Lack of appeal, difficulty to grasp the subject in secondary school and unattractive salary perspectives and professional careers
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