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This paper presents for the first time a novel concept of a MEMS waveguide switch based on a reconfigurable surface, whose working principle is to short-circuit or to allow for free propagation of the electrical field lines of the TE10 mode of a WR-12 rectangular waveguide. This transmissive surface is only 30μm thick and consists of up to 1260 reconfiguring cantilevers in the waveguide cross-section, which are moved simultaneously by integrated MEMS comb-drive actuators. For the first fabrication run, the yield of these reconfigurable elements on the chips was 80-86%, which still was good enough for resulting in a measured insertion loss in the open state of better than 1dB and an isolation of better than 20dB for the best designs, very wideband from 62 to 75GHz. For 100% fabrication yield, HFSS simulations predict that an insertion loss in the open state of better than 0.1dB and an isolation of better than 30dB in the closed state are possible for designs with 800 and more contact points for this novel waveguide switch concept., QC 20130115

This paper reports on the RF performance optimization of multi-stage distributed MEMS devices. The return loss (RL) is optimized, without substantially compromising in overall insertion loss (IL), for a 7-stage MEMS dielectric-block phase shifter by adjusting geometrical parameters of the distributed network, for the nominal frequency of 75 GHz as well as for performance within a 500 MHz and a 1 GHz bandwidth. Different optimization strategies have been investigated by simulations and by measuring fabricated devices. The best optimization concept was found for exponentially increasing distances between the stages, which takes into account the proper actuation sequence for all possible phase-shift combinations. As compared to a non-optimized device previously published, the design offering the best compromise between RL and IL results in a significant average RL improvement of 11.8 dB (simulated) and 6.98 dB (measured), while compromising the average IL by only 0.75 dB (simulated) and 0.92 dB (measured)., QC 20130424

This paper presents for the first time a novel concept of a MEMS waveguide switch based on a reconfigurable surface, whose working principle is to short-circuit or to allow for free propagation of the electrical field lines of the TE10 mode of a WR-12 rectangular waveguide. This transmissive surface is only 30μm thick and consists of up to 1260 reconfiguring cantilevers in the waveguide cross-section, which are moved simultaneously by integrated MEMS comb-drive actuators. For the first fabrication run, the yield of these reconfigurable elements on the chips was 80-86%, which still was good enough for resulting in a measured insertion loss in the open state of better than 1dB and an isolation of better than 20dB for the best designs, very wideband from 62 to 75GHz. For 100% fabrication yield, HFSS simulations predict that an insertion loss in the open state of better than 0.1dB and an isolation of better than 30dB in the closed state are possible for designs with 800 and more contact points for this novel waveguide switch concept., QC 20130115

This paper presents for the first time a novel concept of a MEMS waveguide switch based on a reconfigurable surface, whose working principle is to short-circuit or to allow for free propagation of the electrical field lines of the TE10 mode of a WR-12 rectangular waveguide. This transmissive surface is only 30μm thick and consists of up to 1260 reconfiguring cantilevers in the waveguide cross-section, which are moved simultaneously by integrated MEMS comb-drive actuators. For the first fabrication run, the yield of these reconfigurable elements on the chips was 80-86%, which still was good enough for resulting in a measured insertion loss in the open state of better than 1dB and an isolation of better than 20dB for the best designs, very wideband from 62 to 75GHz. For 100% fabrication yield, HFSS simulations predict that an insertion loss in the open state of better than 0.1dB and an isolation of better than 30dB in the closed state are possible for designs with 800 and more contact points for this novel waveguide switch concept., QC 20130115

This paper presents for the first time a novel concept of a MEMS waveguide switch based on a reconfigurable surface, whose working principle is to short-circuit or to allow for free propagation of the electrical field lines of the TE10 mode of a WR-12 rectangular waveguide. This transmissive surface is only 30μm thick and consists of up to 1260 reconfiguring cantilevers in the waveguide cross-section, which are moved simultaneously by integrated MEMS comb-drive actuators. For the first fabrication run, the yield of these reconfigurable elements on the chips was 80-86%, which still was good enough for resulting in a measured insertion loss in the open state of better than 1dB and an isolation of better than 20dB for the best designs, very wideband from 62 to 75GHz. For 100% fabrication yield, HFSS simulations predict that an insertion loss in the open state of better than 0.1dB and an isolation of better than 30dB in the closed state are possible for designs with 800 and more contact points for this novel waveguide switch concept., QC 20130115

EuMC 2008: 38th European Microwave Conference 2008. 27-31 October 2008. Amsterdam., Adjacent channel leakage power ratio (ACLR) improvement method of a 5-GHz power amplifier using high-temperature superconducting reaction-type transmitting filters (HTS-RTF) is proposed. The aim of this paper is to clarify the amount of ACLR improvement which is offered by HTS-RTFs. Firstly, measurement results of ACLR improvement using a prototype filter is introduced. The prototype filter has an about 10 dB improvement up to 40 dBm Wideband CDMA (W-CDMA) four-carrier signal, even though the suppression band is one side and the bandwidth is narrow. Secondly, to achieve wider suppression band, their resonator structures are optimized. The split-open ring resonator is modified to obtain higher unloaded Q-factor and lower current density. In addition, 5-GHz HTSRTFs which have 3.5 MHz suppression bands in both sides of the W-CDMA carrier signal are designed. Finally, the ACLR improvement obtained by the newly designed filter is estimated based on numerical analysis. The ACLR is improved by about 10 dB in the both sides. Furthermore, the results show that amplifiers' back-off can be reduced by 5 dB when the HTS-RTFs applied to power amplifiers.

In this paper, we present an algorithm which uses the probability information of the input signal to inform the selection of a compressed training dataset for RF PA behavioural model extraction. The proposed algorithm can dramatically reduce the number of training samples. The accuracy of this algorithm is validated by extraction of behavioural models using a large dataset of consecutive samples and a reduced training dataset determined using the proposed algorithm. A noticeable reduction in computational complexity and faster execution time is achieved with the new approach.

In this paper, we present an algorithm which uses the probability information of the input signal to inform the selection of a compressed training dataset for RF PA behavioural model extraction. The proposed algorithm can dramatically reduce the number of training samples. The accuracy of this algorithm is validated by extraction of behavioural models using a large dataset of consecutive samples and a reduced training dataset determined using the proposed algorithm. A noticeable reduction in computational complexity and faster execution time is achieved with the new approach.

© Cambridge University Press and the European Microwave Association, 2012, [EN] In this paper, the use of regularization methods to solve the location problem in multilateration systems, using Mode-S signals, is studied, evaluated, and developed. The Tikhonov method has been implemented as a first application to solve the classical system of hyperbolic equations in multilateration systems. Some simulations are obtained and the results are compared with those obtained by the well-established Taylor linearization and with the Cramér-Rao lower bound analysis. Significant improvements, for the accuracy, convergence, and the probability of location, are found for the application of the Tikhonov method. © Cambridge University Press and the European Microwave Association, 2012.

© Cambridge University Press and the European Microwave Association, 2012, [EN] In this paper, the use of regularization methods to solve the location problem in multilateration systems, using Mode-S signals, is studied, evaluated, and developed. The Tikhonov method has been implemented as a first application to solve the classical system of hyperbolic equations in multilateration systems. Some simulations are obtained and the results are compared with those obtained by the well-established Taylor linearization and with the Cramér-Rao lower bound analysis. Significant improvements, for the accuracy, convergence, and the probability of location, are found for the application of the Tikhonov method. © Cambridge University Press and the European Microwave Association, 2012.

Adjacent channel leakage power ratio (ACLR) improvement method of a 5-GHz power amplifier using high-temperature superconducting reaction-type transmitting filters (HTS-RTF) is proposed. The aim of this paper is to clarify the amount of ACLR improvement which is offered by HTS-RTFs. Firstly, measurement results of ACLR improvement using a prototype filter is introduced. The prototype filter has an about 10 dB improvement up to 40 dBm Wideband CDMA (W-CDMA) four-carrier signal, even though the suppression band is one side and the bandwidth is narrow. Secondly, to achieve wider suppression band, their resonator structures are optimized. The split-open ring resonator is modified to obtain higher unloaded Q-factor and lower current density. In addition, 5-GHz HTSRTFs which have 3.5 MHz suppression bands in both sides of the W-CDMA carrier signal are designed. Finally, the ACLR improvement obtained by the newly designed filter is estimated based on numerical analysis. The ACLR is improved by about 10 dB in the both sides. Furthermore, the results show that amplifiers' back-off can be reduced by 5 dB when the HTS-RTFs applied to power amplifiers., EuMC 2008: 38th European Microwave Conference 2008. 27-31 October 2008. Amsterdam.

Adjacent channel leakage power ratio (ACLR) improvement method of a 5-GHz power amplifier using high-temperature superconducting reaction-type transmitting filters (HTS-RTF) is proposed. The aim of this paper is to clarify the amount of ACLR improvement which is offered by HTS-RTFs. Firstly, measurement results of ACLR improvement using a prototype filter is introduced. The prototype filter has an about 10 dB improvement up to 40 dBm Wideband CDMA (W-CDMA) four-carrier signal, even though the suppression band is one side and the bandwidth is narrow. Secondly, to achieve wider suppression band, their resonator structures are optimized. The split-open ring resonator is modified to obtain higher unloaded Q-factor and lower current density. In addition, 5-GHz HTSRTFs which have 3.5 MHz suppression bands in both sides of the W-CDMA carrier signal are designed. Finally, the ACLR improvement obtained by the newly designed filter is estimated based on numerical analysis. The ACLR is improved by about 10 dB in the both sides. Furthermore, the results show that amplifiers' back-off can be reduced by 5 dB when the HTS-RTFs applied to power amplifiers., EuMC 2008: 38th European Microwave Conference 2008. 27-31 October 2008. Amsterdam.

Adjacent channel leakage power ratio (ACLR) improvement method of a 5-GHz power amplifier using high-temperature superconducting reaction-type transmitting filters (HTS-RTF) is proposed. The aim of this paper is to clarify the amount of ACLR improvement which is offered by HTS-RTFs. Firstly, measurement results of ACLR improvement using a prototype filter is introduced. The prototype filter has an about 10 dB improvement up to 40 dBm Wideband CDMA (W-CDMA) four-carrier signal, even though the suppression band is one side and the bandwidth is narrow. Secondly, to achieve wider suppression band, their resonator structures are optimized. The split-open ring resonator is modified to obtain higher unloaded Q-factor and lower current density. In addition, 5-GHz HTSRTFs which have 3.5 MHz suppression bands in both sides of the W-CDMA carrier signal are designed. Finally, the ACLR improvement obtained by the newly designed filter is estimated based on numerical analysis. The ACLR is improved by about 10 dB in the both sides. Furthermore, the results show that amplifiers' back-off can be reduced by 5 dB when the HTS-RTFs applied to power amplifiers., EuMC 2008: 38th European Microwave Conference 2008. 27-31 October 2008. Amsterdam.

In this paper, the design and the results of a CMOS Silicon-On-Insulator (SOI) traveling wave amplifier (TWA) versus temperature are presented. The four stage TWA is designed with a single common source n-MOSFET in each stage using a 130 nm SOI CMOS technology requiring a chip area of 0.75 mm/sup 2/. A gain of 4.5 dB and a unity-gain bandwidth of 30 GHz are measured at 1.4 V supply voltage with a measured power consumption of 66 mW. The designed circuit has been characterized over a temperature range from 25 to 300 degrees C. The performance degradation on the gain of the TWA, the SOI transistors as well as the microstrip lines used for the matching network are analyzed., Anglais