Eduardo Artal - Academia.edu (original) (raw)

Papers by Eduardo Artal

Cryogenics, 2019

The performance of silicon-germanium (SiGe) transistors under cryogenic operation is analyzed. Th... more The performance of silicon-germanium (SiGe) transistors under cryogenic operation is analyzed. The design and characterization of a 3-14 GHz low-noise amplifier (LNA) using SiGe transistors at 300 K and at 13 K are presented. A three stage amplifier is implemented with bipolar transistors model BFU910F from NXP commercially available with a plastic package. The amplifier exhibits 36.8 dB average gain with average noise temperature of 103 K and 42 mW DC power consumption at 300 K ambient temperature. Whereas cooled down to 13 K ambient temperature, it provides 32.4 dB average gain, 11.4 K average noise temperature with a minimum of 7.2 K at 3.5 GHz and a DC power dissipation of 5.8 mW. The presented LNA demonstrates an outstanding performance at cryogenic temperature for a commercial plastic packaged transistor.

IEEE Transactions on Microwave Theory and Techniques

Lumped-element superconducting resonators are a promising technology for their use in millimeter-... more Lumped-element superconducting resonators are a promising technology for their use in millimeter-wave observations and quantum computing applications that require large arrays of extremely sensitive detectors. Among them, lumped-element kinetic inductance detectors (LEKIDs) have shown good performance in the submillimeter band in several earth-based telescopes. In this work, LEKIDs for their use as millimeter-wave receivers of astronomical applications are presented. LEKID arrays using a thin bilayer of superconducting titanium/aluminum (Ti/Al), deposited on the silicon substrate, have been designed and fabricated. The design of a dual-polarization LEKID with the goal of detection at the WWW -band for two orthogonal polarizations is described and a fabricated array has demonstrated absorption at ambient temperature. Also, an approximate design methodology of the coupling parameter for LEKIDs’ readout, essential for dynamic range optimization of the detector under millimeter-wave radiation, is proposed. In addition, the resonance characteristics and coupling factor of the fabricated superconducting resonators using high-quality internal factor QiQ_{i}Qi under cryogenic temperatures have been analyzed. The design guidelines in this work are applicable to other LEKID arrays, and the presented superconducting Ti/Al thin-film LEKIDs can be used in future receiver arrays in the millimeter bands.

IEEE Transactions on Microwave Theory and Techniques

A novel full-band (40% relative bandwidth) waveguide polar modulator (WPM) design based on a new ... more A novel full-band (40% relative bandwidth) waveguide polar modulator (WPM) design based on a new architecture with two turnstile junctions and a nearly frequencyindependent differential 180°phase shift between orthogonal arms is presented. The use of suitably designed turnstile junctions together with antiphase waveguide-coaxial-waveguide transitions in reduced-height waveguide technology enables the improvement of bandwidth over previous WPMs with a very compact and simple solution. This design enables continuous rotation about its central axis at 40 revolutions/s, which makes the modulator suitable for receivers with significant 1/ f noise such as cryogenic radiometers. The polar modulator presented in this paper is designed to be cooled down to cryogenic temperatures in order to reduce its contribution to the receiver noise. This design is suitable for radio astronomy applications due to its costeffective, compact design, and high quality performance as well as being readily scalable. A polar modulator in the Ka-band (26.5-40 GHz) has been designed to show a reflection better than −20 dB, an insertion loss around 0.3 dB, and a cross-coupling near −35 dB measured at room temperature (T = 298 K). This insertion loss is reduced by 30%, while the phase difference and cross-coupling maintain similar values when the polar modulator is cooled to approximately T = 80 K.

A system which combines the properties of the PLL systems and the injection locking ones is descr... more A system which combines the properties of the PLL systems and the injection locking ones is described. Its theoretical behaviour is analysed and some practical applications are discussed. Its performance in these aplications has been verified at the laboratory and sorne results are given.

Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy X

Broadband radiometers at 30 and 40 GHz for QUIJOTE radio astronomy experiment are very sensitive ... more Broadband radiometers at 30 and 40 GHz for QUIJOTE radio astronomy experiment are very sensitive receivers to perform scientific sky observations of the Cosmic Microwave Background (CMB). The aim of this experiment is the linear polarization percentage measurement of the received signals. Radiometers have cryogenically cooled Front-End Modules followed by room temperature amplification, correlation and detection modules. Their relative bandwidth is around 30%. There are 30 receivers (pixels) at 30 GHz and 29 receivers at 40 GHz. The radiometer scheme is based on two balanced branches, microwave correlation and direct detection. The manufactured receivers measure Stokes polarization parameters I, Q, and U simultaneously. This paper describes the principle of operation of polarimeter receivers, and present details of manufactured subsystems, integration and test results. Receivers integrate different technologies: waveguides, microstrip, Monolithic Microwave Integrated Circuits (MMIC) and active and passive devices. The receivers are currently under installation in El Teide Observatory, Tenerife (Canary Islands, Spain).

Electronics, 2021

A new configuration of a pseudo-correlation type radiometer is proposed for a microwave biomedica... more A new configuration of a pseudo-correlation type radiometer is proposed for a microwave biomedical application, such as diabetic foot neuropathy. The new approach as well as its simulated performance are thoroughly assessed using commercial off-the-shelf components and custom designed subsystems. We configured a pseudo-correlation receiver, centred at 3.5 GHz, to validate the proposal, comparing its simulated response with a measured alternative based on a 90∘ hybrid coupler pseudo-correlation prototype. We custom designed a balanced Wilkinson power divider and a 180∘ hybrid coupler to fulfil the receiver’s requirements. The proposed configuration demonstrated an improved noise temperature response. The main advantage is to enable the recalibration of the receiver through simultaneous measurable output signals, proportional to each input signal, as well as the correlated response between them.

The direct broadcast satellite receiver in the 12 GHz band developed in the Electrophysics Depart... more The direct broadcast satellite receiver in the 12 GHz band developed in the Electrophysics Department in cooperation with the R & D Departments of Mier Allende, S.A. and Tagra, S.A. is described. It features a low-noise amplifier with 0.3 and 0.5 mm gate width- GaAs MESFET, balanced mixer and monolithic IF amplifier along with filters, polarizer and feeder. The system has been integrated in a module installed in the focus a 0. 4 - f/D parabolic reflector. Noise figures lesser than 3 dB have been obtained leading to G/T factors greater than 24.5 db/K when using a 3 meterantenna.

2011 41st European Microwave Conference, 2011

The 26–36 GHz receiver for a radio astronomy radiometer, to characterize the polarization of the ... more The 26–36 GHz receiver for a radio astronomy radiometer, to characterize the polarization of the Cosmic Microwave Background, is presented. This receiver is based on very low noise cryogenically cooled amplifiers in the front-end module, while in the back-end module a broadband amplification and direct detection chain is operated at room temperature. Noise temperature of the low-noise amplifier (LNA) is 19 K when cooled at 18 K. Experimental results show a good sensitivity of the complete receiver with an effective bandwidth around 8 GHz. Moreover, output detected voltages agree with estimated values.

A digital radio-relay link in the band 10.7- 11.7 GHz developed for the remote control system of ... more A digital radio-relay link in the band 10.7- 11.7 GHz developed for the remote control system of ENHER is presented. The objectives were the construction of a reliable and yet low-cost transmitter-receiver. To accomplish this, the RF unit has been constructed in microstrip on plastic substrate, and the FI from commercially available TV subsystems. The version herein presented has a 200 kbits/s capacity (susceptible of being increased) and can operate on vanes of at least 5 km.

Context. This paper provides an overview of the Low Frequency Instrument (LFI) programme within t... more Context. This paper provides an overview of the Low Frequency Instrument (LFI) programme within the ESA Planck mission. Aims. The LFI instrument has been developed to produce high precision maps of the microwave sky at frequencies in the 27÷77 GHz range, below the peak of the Cosmic Microwave Background (CMB) radiation spectrum. Methods. The scientific goals are described, ranging from mainstream cosmology to Galactic and extragalactic astrophysics. The instrument design and development is outlined, together with the model philosophy and testing strategy. The instrument is presented in the context of the Planck mission. The LFI approach to on-ground and in-flight calibration is described. We also provide a description of the LFI ground segment. We present results of a number of tests that demonstrate the capability of the LFI Data Processing Centre (DPC) to properly reduce and analyse LFI flight data, from tel emetry information to sky maps and other scientific products . The organi...

A radiometer simulation procedure with special emphasis on high frequencies and switched system p... more A radiometer simulation procedure with special emphasis on high frequencies and switched system performance is discussed. The whole system simulation is implemented in Envelope-Transient, a combination of frequency domain and time domain, on the same software platform which is used to design separate microwave components, allowing the use of measured S parameters and measured current-voltage characteristics of the detectors. 1/f gain fluctuations are introduced in the simulations and switched differential operation is implemented and validated as a way to minimize their impact. Low frequencies are scaled-up to allow the simulator a reasonable CPU time and memory handling without losing generality. Coupling between a base-band equivalent solution and a complete mm-wave solution is provided by the proposed simulation, providing a step beyond typical separate analysis of RF parts and base-band equivalent in this kind of systems.

A wideband coplanar to microstrip transition without via holes has been used for device testing a... more A wideband coplanar to microstrip transition without via holes has been used for device testing at millimetre wave frequencies (from 20 to 40 GHz), in order to have an accurate characterisation of the tested devices. Circuits under tests are built on 0.254 mm thick Alumina substrate. Test method, with a coplanar probe station, has been checked with different devices, and validated by comparison with commercial coplanar to microstrip transitions with via holes.

Electronics

W-Band radiometers using intermediate frequency down-conversion (super-heterodyne) and direct det... more W-Band radiometers using intermediate frequency down-conversion (super-heterodyne) and direct detection are compared. Both receivers consist of two W-band low noise amplifiers and an 80-to-101 GHz filter, which conforms to the reception frequency band, in the front-end module. The back-end module of the first receiver comprises a subharmonic mixer, intermediate frequency (IF) amplification and a square-law detector. For direct detection, a W-Band detector replaces the mixer and the intermediate frequency detection stages. The performance of the whole receivers has been simulated requiring special techniques, based on data from the experimental characterization of each subsystem. In the super-heterodyne implementation a local oscillator at 27.1 GHz (with 8 dBm) with a x3 frequency multiplier is used, exhibiting an overall conversion gain around 48 dB, a noise figure around 4 dB, and an effective bandwidth over 10 GHz. In the direct detection scheme, slightly better noise performance ...

IEEE Transactions on Microwave Theory and Techniques

A wideband (30% relative bandwidth) correlation and detection module based on substrate-integrate... more A wideband (30% relative bandwidth) correlation and detection module based on substrate-integrated waveguide (SIW) technology intended for a radio astronomy polarimeter is presented. The SIW circuit is a six-port network with two input ports that are correlated in two hybrid couplers and their corresponding output signals are routed to Schottky diode detectors, which are designed using microstrip technology and assembled within the same system. The designed SIW structure includes hybrid couplers, power dividers, a 90°phase shifter, and 90°bends, providing a real implementation of a functional system with improved bandwidth performance from 35 to 47 GHz. Experimental results are in concordance with simulations, and they validate the module operation for the proposed application.

IEEE Transactions on Electron Devices

Thermal capacitances are required to describe fast dynamic thermal behavior in SOI devices. This ... more Thermal capacitances are required to describe fast dynamic thermal behavior in SOI devices. This paper presents a physical model based on the AC technique, together with the characteristic thermal frequency determination through the frequency response of the output conductance, for calculating the thermal capacitance of single-finger and multi-finger SOI-MOSFETs. The model accounts for total gate width and substrate temperature, making evident the augmented thermal coupling when multi-fingers are used. Thermal capacitances and corresponding time constants, extracted from a variety of gate widths and number of fingers, are correctly predicted up to a substrate temperature of 150°C. Index Terms-electrothermal characterization, model, SOI-MOSFET, substrate temperature, thermal capacitance. I. INTRODUCTION ilicon-on-insulator (SOI) MOSFETs, having a buried oxide layer thicker than 100 nm, suffer from obstruction of the heat flow towards the substrate [1], [2]. This, together with the ultra-thin internal layers used at nanometer length scales, with a reduced thermal conductivity [3], [4], results in a remarkable self-heating effect, particularly in DC operation/biasing with relevant electrical power levels involved (as from dozens of mW [5]). This makes the design and configuration of terminals, acting as heat sinks, critical in SOI-MOSFET performance [1], [6]. The typical thermal model for the temperature rise in devices, induced by self-heating effects, consists of the equivalent circuit shown in Fig. 1, with the thermal resistance, Rth, and capacitance, Cth, being connected in parallel. This model is based on the following analogy between electrical

Cryogenics, 2019

The performance of silicon-germanium (SiGe) transistors under cryogenic operation is analyzed. Th... more The performance of silicon-germanium (SiGe) transistors under cryogenic operation is analyzed. The design and characterization of a 3-14 GHz low-noise amplifier (LNA) using SiGe transistors at 300 K and at 13 K are presented. A three stage amplifier is implemented with bipolar transistors model BFU910F from NXP commercially available with a plastic package. The amplifier exhibits 36.8 dB average gain with average noise temperature of 103 K and 42 mW DC power consumption at 300 K ambient temperature. Whereas cooled down to 13 K ambient temperature, it provides 32.4 dB average gain, 11.4 K average noise temperature with a minimum of 7.2 K at 3.5 GHz and a DC power dissipation of 5.8 mW. The presented LNA demonstrates an outstanding performance at cryogenic temperature for a commercial plastic packaged transistor.

IEEE Transactions on Microwave Theory and Techniques

Lumped-element superconducting resonators are a promising technology for their use in millimeter-... more Lumped-element superconducting resonators are a promising technology for their use in millimeter-wave observations and quantum computing applications that require large arrays of extremely sensitive detectors. Among them, lumped-element kinetic inductance detectors (LEKIDs) have shown good performance in the submillimeter band in several earth-based telescopes. In this work, LEKIDs for their use as millimeter-wave receivers of astronomical applications are presented. LEKID arrays using a thin bilayer of superconducting titanium/aluminum (Ti/Al), deposited on the silicon substrate, have been designed and fabricated. The design of a dual-polarization LEKID with the goal of detection at the WWW -band for two orthogonal polarizations is described and a fabricated array has demonstrated absorption at ambient temperature. Also, an approximate design methodology of the coupling parameter for LEKIDs’ readout, essential for dynamic range optimization of the detector under millimeter-wave radiation, is proposed. In addition, the resonance characteristics and coupling factor of the fabricated superconducting resonators using high-quality internal factor QiQ_{i}Qi under cryogenic temperatures have been analyzed. The design guidelines in this work are applicable to other LEKID arrays, and the presented superconducting Ti/Al thin-film LEKIDs can be used in future receiver arrays in the millimeter bands.

IEEE Transactions on Microwave Theory and Techniques

A novel full-band (40% relative bandwidth) waveguide polar modulator (WPM) design based on a new ... more A novel full-band (40% relative bandwidth) waveguide polar modulator (WPM) design based on a new architecture with two turnstile junctions and a nearly frequencyindependent differential 180°phase shift between orthogonal arms is presented. The use of suitably designed turnstile junctions together with antiphase waveguide-coaxial-waveguide transitions in reduced-height waveguide technology enables the improvement of bandwidth over previous WPMs with a very compact and simple solution. This design enables continuous rotation about its central axis at 40 revolutions/s, which makes the modulator suitable for receivers with significant 1/ f noise such as cryogenic radiometers. The polar modulator presented in this paper is designed to be cooled down to cryogenic temperatures in order to reduce its contribution to the receiver noise. This design is suitable for radio astronomy applications due to its costeffective, compact design, and high quality performance as well as being readily scalable. A polar modulator in the Ka-band (26.5-40 GHz) has been designed to show a reflection better than −20 dB, an insertion loss around 0.3 dB, and a cross-coupling near −35 dB measured at room temperature (T = 298 K). This insertion loss is reduced by 30%, while the phase difference and cross-coupling maintain similar values when the polar modulator is cooled to approximately T = 80 K.

A system which combines the properties of the PLL systems and the injection locking ones is descr... more A system which combines the properties of the PLL systems and the injection locking ones is described. Its theoretical behaviour is analysed and some practical applications are discussed. Its performance in these aplications has been verified at the laboratory and sorne results are given.

Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy X

Broadband radiometers at 30 and 40 GHz for QUIJOTE radio astronomy experiment are very sensitive ... more Broadband radiometers at 30 and 40 GHz for QUIJOTE radio astronomy experiment are very sensitive receivers to perform scientific sky observations of the Cosmic Microwave Background (CMB). The aim of this experiment is the linear polarization percentage measurement of the received signals. Radiometers have cryogenically cooled Front-End Modules followed by room temperature amplification, correlation and detection modules. Their relative bandwidth is around 30%. There are 30 receivers (pixels) at 30 GHz and 29 receivers at 40 GHz. The radiometer scheme is based on two balanced branches, microwave correlation and direct detection. The manufactured receivers measure Stokes polarization parameters I, Q, and U simultaneously. This paper describes the principle of operation of polarimeter receivers, and present details of manufactured subsystems, integration and test results. Receivers integrate different technologies: waveguides, microstrip, Monolithic Microwave Integrated Circuits (MMIC) and active and passive devices. The receivers are currently under installation in El Teide Observatory, Tenerife (Canary Islands, Spain).

Electronics, 2021

A new configuration of a pseudo-correlation type radiometer is proposed for a microwave biomedica... more A new configuration of a pseudo-correlation type radiometer is proposed for a microwave biomedical application, such as diabetic foot neuropathy. The new approach as well as its simulated performance are thoroughly assessed using commercial off-the-shelf components and custom designed subsystems. We configured a pseudo-correlation receiver, centred at 3.5 GHz, to validate the proposal, comparing its simulated response with a measured alternative based on a 90∘ hybrid coupler pseudo-correlation prototype. We custom designed a balanced Wilkinson power divider and a 180∘ hybrid coupler to fulfil the receiver’s requirements. The proposed configuration demonstrated an improved noise temperature response. The main advantage is to enable the recalibration of the receiver through simultaneous measurable output signals, proportional to each input signal, as well as the correlated response between them.

The direct broadcast satellite receiver in the 12 GHz band developed in the Electrophysics Depart... more The direct broadcast satellite receiver in the 12 GHz band developed in the Electrophysics Department in cooperation with the R & D Departments of Mier Allende, S.A. and Tagra, S.A. is described. It features a low-noise amplifier with 0.3 and 0.5 mm gate width- GaAs MESFET, balanced mixer and monolithic IF amplifier along with filters, polarizer and feeder. The system has been integrated in a module installed in the focus a 0. 4 - f/D parabolic reflector. Noise figures lesser than 3 dB have been obtained leading to G/T factors greater than 24.5 db/K when using a 3 meterantenna.

2011 41st European Microwave Conference, 2011

The 26–36 GHz receiver for a radio astronomy radiometer, to characterize the polarization of the ... more The 26–36 GHz receiver for a radio astronomy radiometer, to characterize the polarization of the Cosmic Microwave Background, is presented. This receiver is based on very low noise cryogenically cooled amplifiers in the front-end module, while in the back-end module a broadband amplification and direct detection chain is operated at room temperature. Noise temperature of the low-noise amplifier (LNA) is 19 K when cooled at 18 K. Experimental results show a good sensitivity of the complete receiver with an effective bandwidth around 8 GHz. Moreover, output detected voltages agree with estimated values.

A digital radio-relay link in the band 10.7- 11.7 GHz developed for the remote control system of ... more A digital radio-relay link in the band 10.7- 11.7 GHz developed for the remote control system of ENHER is presented. The objectives were the construction of a reliable and yet low-cost transmitter-receiver. To accomplish this, the RF unit has been constructed in microstrip on plastic substrate, and the FI from commercially available TV subsystems. The version herein presented has a 200 kbits/s capacity (susceptible of being increased) and can operate on vanes of at least 5 km.

Context. This paper provides an overview of the Low Frequency Instrument (LFI) programme within t... more Context. This paper provides an overview of the Low Frequency Instrument (LFI) programme within the ESA Planck mission. Aims. The LFI instrument has been developed to produce high precision maps of the microwave sky at frequencies in the 27÷77 GHz range, below the peak of the Cosmic Microwave Background (CMB) radiation spectrum. Methods. The scientific goals are described, ranging from mainstream cosmology to Galactic and extragalactic astrophysics. The instrument design and development is outlined, together with the model philosophy and testing strategy. The instrument is presented in the context of the Planck mission. The LFI approach to on-ground and in-flight calibration is described. We also provide a description of the LFI ground segment. We present results of a number of tests that demonstrate the capability of the LFI Data Processing Centre (DPC) to properly reduce and analyse LFI flight data, from tel emetry information to sky maps and other scientific products . The organi...

A radiometer simulation procedure with special emphasis on high frequencies and switched system p... more A radiometer simulation procedure with special emphasis on high frequencies and switched system performance is discussed. The whole system simulation is implemented in Envelope-Transient, a combination of frequency domain and time domain, on the same software platform which is used to design separate microwave components, allowing the use of measured S parameters and measured current-voltage characteristics of the detectors. 1/f gain fluctuations are introduced in the simulations and switched differential operation is implemented and validated as a way to minimize their impact. Low frequencies are scaled-up to allow the simulator a reasonable CPU time and memory handling without losing generality. Coupling between a base-band equivalent solution and a complete mm-wave solution is provided by the proposed simulation, providing a step beyond typical separate analysis of RF parts and base-band equivalent in this kind of systems.

A wideband coplanar to microstrip transition without via holes has been used for device testing a... more A wideband coplanar to microstrip transition without via holes has been used for device testing at millimetre wave frequencies (from 20 to 40 GHz), in order to have an accurate characterisation of the tested devices. Circuits under tests are built on 0.254 mm thick Alumina substrate. Test method, with a coplanar probe station, has been checked with different devices, and validated by comparison with commercial coplanar to microstrip transitions with via holes.

Electronics

W-Band radiometers using intermediate frequency down-conversion (super-heterodyne) and direct det... more W-Band radiometers using intermediate frequency down-conversion (super-heterodyne) and direct detection are compared. Both receivers consist of two W-band low noise amplifiers and an 80-to-101 GHz filter, which conforms to the reception frequency band, in the front-end module. The back-end module of the first receiver comprises a subharmonic mixer, intermediate frequency (IF) amplification and a square-law detector. For direct detection, a W-Band detector replaces the mixer and the intermediate frequency detection stages. The performance of the whole receivers has been simulated requiring special techniques, based on data from the experimental characterization of each subsystem. In the super-heterodyne implementation a local oscillator at 27.1 GHz (with 8 dBm) with a x3 frequency multiplier is used, exhibiting an overall conversion gain around 48 dB, a noise figure around 4 dB, and an effective bandwidth over 10 GHz. In the direct detection scheme, slightly better noise performance ...

IEEE Transactions on Microwave Theory and Techniques

A wideband (30% relative bandwidth) correlation and detection module based on substrate-integrate... more A wideband (30% relative bandwidth) correlation and detection module based on substrate-integrated waveguide (SIW) technology intended for a radio astronomy polarimeter is presented. The SIW circuit is a six-port network with two input ports that are correlated in two hybrid couplers and their corresponding output signals are routed to Schottky diode detectors, which are designed using microstrip technology and assembled within the same system. The designed SIW structure includes hybrid couplers, power dividers, a 90°phase shifter, and 90°bends, providing a real implementation of a functional system with improved bandwidth performance from 35 to 47 GHz. Experimental results are in concordance with simulations, and they validate the module operation for the proposed application.

IEEE Transactions on Electron Devices

Thermal capacitances are required to describe fast dynamic thermal behavior in SOI devices. This ... more Thermal capacitances are required to describe fast dynamic thermal behavior in SOI devices. This paper presents a physical model based on the AC technique, together with the characteristic thermal frequency determination through the frequency response of the output conductance, for calculating the thermal capacitance of single-finger and multi-finger SOI-MOSFETs. The model accounts for total gate width and substrate temperature, making evident the augmented thermal coupling when multi-fingers are used. Thermal capacitances and corresponding time constants, extracted from a variety of gate widths and number of fingers, are correctly predicted up to a substrate temperature of 150°C. Index Terms-electrothermal characterization, model, SOI-MOSFET, substrate temperature, thermal capacitance. I. INTRODUCTION ilicon-on-insulator (SOI) MOSFETs, having a buried oxide layer thicker than 100 nm, suffer from obstruction of the heat flow towards the substrate [1], [2]. This, together with the ultra-thin internal layers used at nanometer length scales, with a reduced thermal conductivity [3], [4], results in a remarkable self-heating effect, particularly in DC operation/biasing with relevant electrical power levels involved (as from dozens of mW [5]). This makes the design and configuration of terminals, acting as heat sinks, critical in SOI-MOSFET performance [1], [6]. The typical thermal model for the temperature rise in devices, induced by self-heating effects, consists of the equivalent circuit shown in Fig. 1, with the thermal resistance, Rth, and capacitance, Cth, being connected in parallel. This model is based on the following analogy between electrical