Current Issue : April - June Volume : 2013 Issue Number : 2 Articles : 6 Articles
This paper reports a 12GHz rotary travelling wave (RTW) voltage controlled oscillator designed in a 130nm CMOS technology.\r\nThe phase noise and power consumption performances were compared with the literature and with telecommunication standards\r\nfor broadcast satellite applications. The RTW VCO exhibits a -106 dBc/Hz at 1MHz and a 30mW power consumption with a\r\nsensibility of 400 MHz/V. Finally, requirements are given for a PLL implementation of the RTW VCO and simulated results are\r\npresented....
A wireless power transfer system using an inductive link has been demonstrated for implantable sensor applications. The system\r\nis composed of two primary blocks: an inductive power transfer unit and a backward data communication unit. The inductive\r\nlink performs two functions: coupling the required power from a wireless power supply system enabling battery-less, long-term\r\nimplant operation and providing a backward data transmission path. The backward data communication unit transmits the data\r\nto an outside reader using FSK modulation scheme via the inductive link. To demonstrate the operation of the inductive link, a\r\nboard-level design has been implemented with high link efficiency. Test results from a fabricated sensor system, composed of a\r\nhybrid implementation of custom-integrated circuits and board-level discrete components, are presented demonstrating power\r\ntransmission of 125mW with a 12.5% power link transmission efficiency. Simultaneous backward data communication involving\r\na digital pulse rate of up to 10 kbps was also observed....
In a previous study, we have demonstrated that beryllium oxide (BeO) film grown by atomic layer deposition (ALD) on Si and\r\nIII-V MOS devices has excellent electrical and physical characteristics. In this paper, we compare the electrical characteristics\r\nof inserting an ultrathin interfacial barrier layer such as SiO2, Al2O3, or BeO between the HfO2 gate dielectric and Si substrate in\r\nmetal oxide semiconductor capacitors (MOSCAPs) and n-channel inversion type metal oxide semiconductor field effect transistors\r\n(MOSFETs). Si MOSCAPs and MOSFETs with a BeO/HfO2 gate stack exhibited high performance and reliability characteristics,\r\nincluding a 34% improvement in drive current, slightly better reduction in subthreshold swing, 42% increase in effective electron\r\nmobility at an electric field of 1 MV/cm, slightly low equivalent oxide thickness, less stress-induced flat-band voltage shift, less\r\nstress induced leakage current, and less interface charge....
The electrical characteristics of TiO2 films grown on III-V semiconductors (e.g., p-type InP and GaAs) by metal-organic chemical\r\nvapor deposition were studied. With (NH4)2S treatment, the electrical characteristics of MOS capacitors are improved due to the\r\nreduction of native oxides. The electrical characteristics can be further improved by the postmetallization annealing, which causes\r\nhydrogen atomic ion to passivate defects and the grain boundary of polycrystalline TiO2 films. For postmetallization annealed TiO2\r\non (NH4)2S treated InP MOS, the leakage current densities can reach 2.7 Ã?â?? 10-7 and 2.3 Ã?â?? 10-7 A/cm2 at Ã?±1 MV/cm, respectively.\r\nThe dielectric constant and effective oxide charges are 46 and 1.96 Ã?â?? 1012 C/cm2, respectively. The interface state density is 7.13 Ã?â??\r\n1011 cm-2 eV-1 at the energy of 0.67 eV from the edge of valence band. For postmetallization annealed TiO2 on (NH4)2S treated\r\nGaAs MOS, The leakage current densities can reach 9.7 Ã?â?? 10-8 and 1.4 Ã?â?? 10-7 at Ã?±1 MV/cm, respectively. The dielectric constant\r\nand effective oxide charges are 66 and 1.86 Ã?â?? 1012 C/cm2, respectively. The interface state density is 5.96 Ã?â?? 1011 cm-2 eV-1 at the\r\nenergy of 0.7 eV from the edge of valence band....
This study examines the praseodymium-oxide- (Pr2O3-) passivated AlGaN/GaN metal-insulator-semiconductor high electron\r\nmobility transistors (MIS-HEMTs) with high dielectric constant in which the AlGaN Schottky layers are treated with\r\nP2S5/(NH4)2SX + ultraviolet (UV) illumination. An electron-beam evaporated Pr2O3 insulator is used instead of traditional\r\nplasma-assisted chemical vapor deposition (PECVD), in order to prevent plasma-induced damage to the AlGaN. In this work,\r\nthe HEMTs are pretreated with P2S5/(NH4)2SX solution and UV illumination before the gate insulator (Pr2O3) is deposited. Since\r\nstable sulfur that is bound to the Ga species can be obtained easily and surface oxygen atoms are reduced by the P2S5/(NH4)2SX\r\npretreatment, the lowest leakage current is observed in MIS-HEMT. Additionally, a low flicker noise and a low surface roughness\r\n(0.38 nm) are also obtained using this novel process, which demonstrates its ability to reduce the surface states. Low gate leakage\r\ncurrent Pr2O3 and high-k AlGaN/GaN MIS-HEMTs, with P2S5/(NH4)2SX + UV illumination treatment, are suited to low-noise\r\napplications, because of the electron-beam-evaporated insulator and the new chemical pretreatment....
Defect is one of the key factors in reducing the reliability of the insulated gate bipolar transistor (IGBT) module, so developing\r\nthe diagnostic method for defects inside the IGBT module is an important measure to avoid catastrophic failure and improves the\r\nreliability of power electronic converters. For this reason, a novel diagnostic method based on the approximate entropy (ApEn)\r\ntheory is presented in this paper, which can provide statistical diagnosis and allow the operator to replace defective IGBT modules\r\ntimely. The proposed method is achieved by analyzing the cross ApEn of the gate voltages before and after the occurring of defects.\r\nDue to the local damage caused by aging, the intrinsic parasitic parameters of packaging materials or silicon chips inside the IGBT\r\nmodule such as parasitic inductances and capacitances may change over time, which will make remarkable variation in the gate\r\nvoltage. That is to say the gate voltage is close coupled with the defects. Therefore, the variation is quantified and used as a precursor\r\nparameter to evaluate the health status of the IGBT module. Experimental results validate the correctness of the proposed method....
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