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In earlier work [1,2] the potential for detecting and tracking a target using maximal length sequences with block zeroing was demonstrated via theory and simulation. In an initial application of this work, a -20 dB acoustic target was detected and tracked at a source-target distance of approximately 170 m in water 2 m deep. Using the sonar equation, the detection performance of a maximal length sequence,...
This paper reports the capability of AlGaN/GaN HEMTs on Si (111) substrates for microwave power applications above 30 GHz. A current gain cut-off frequency ft=90 GHz and a maximum power gain cut-off frequency fmax=135 GHz are obtained for a 80 nm gate-length transistor. These results, associated with low lag effects, demonstrate the capability of these transistors for high performance, cost effective,...
We present recent results on the direct heterogeneous integration of InP HBTs and Si CMOS on a silicon template wafer or SOLES (Silicon On Lattice Engineered Substrate). InP HBTs whose performance are comparable to HBTs on the native InP substrates have been repeatedly achieved. 100% heterogeneous interconnect yield has been achieved on daisy chain test structures with CMOS-InP HBT spacing (interconnect...
In this paper, we present small and large signal data of a switched LNA hybrid circuit implemented using a low-loss and high linearity RF MEMS switching network on a GaAs MMIC wafer. The GaAs MEMS based reconfigurable LNA front-end circuit can achieve a 30 dB difference in in-band gain and attenuation (when the switch is turned on and off) while also being able to maintain a high gain (low noise figure)...
We present the design criteria and specifications of a novel Open-Source hardware channel sounder and Open-Source data sets for measurements of the Body Area Channel at the 2400MHz ISM band and 2360MHz band. We outline a need for open hardware and measurement data to facilitate robust standardization of the new Body Area Networks. We demonstrate typical analyses on a public data set, with reference...
In the paper, we solve the so-called open problems for electromagnetic field distribution in axially symmetrical open resonant structures. We construct the Exact Absorbing Conditions that allow efficient truncating the computational domain. Proof of equivalency between these initial and modified problems will also be provided.
The response of aperture-backed cavities and other highly resonant scatterers can pose difficulties for general purpose computational codes, in both time- and frequency-domain. An accurate, numerically efficient frequency domain solution is developed for the scalar wave diffraction problem from an arbitrary shaped body of revolution, either closed or having an aperture. The Dirichlet boundary condition...
The fabrication of high transconductance AlGaN/GaN high electron mobility transistors (HEMTs) grown on high-resistivity silicon substrate is reported with an AlGaN barrier thickness of only 12.5 nm. A maximum DC current density of 655 mA/mm, a current gain cutoff frequency (FT) of 75 GHz and a power-gain cutoff frequency (FMAX) of 125 GHz are obtained for a 0.125 μm gate length transistor. The device...
This work provides a brief outline of the basic theory of indirect microwave holography. This is supported by experimental work which illustrates how this technique can be used successfully in a number of areas including antenna measurements, concealed weapons detection and medical imaging.
In large-scale compute cloud systems, component failures become norms instead of exceptions. Failure occurrence as well as its impact on system performance and operation costs are becoming an increasingly important concern to system designers and administrators. When a system fails to function properly, health-related data are valuable for troubleshooting. However, it is challenging to effectively...
RF-MEMS is an emerging area of MEMS technology that is revolutionizing RF- and microwave applications. RF-MEMS devices have a broad range of applications in military and commercial wireless communication, navigation and sensor systems. Agile RF-systems require reconfigurable frontends that can steer the beam over a wide frequency range. Such applications always require some kind of switches. The RF...
This article describes the progress made during the first project year of the FP7 EU-project MEMS-4-MMIC that focuses on the merging of innovative RF-MEMS switch designs with established MMIC-technology. The ultimate goal is to include RF-MEMS switches into a standard commercial foundry process. Such switches will then become standard building blocks for MMIC circuits such as transistors, resistors...
Herein, the performance of low-cost crystalline silicon solar cells under low to medium levels of concentration is explored. Simulations and experimental results are shown for concentrations up to 20 suns. An efficiency of 23% at 9 suns is achieved on a 34.5 mm × 125 mm solar cell using SunPower's standard production process. Low sensitivity of cell performance to illumination profile and position...
This paper reports recent progress by SunPower Corporation to commercialize the Generation 3 product. The Generation 3 product has been designed to deliver both increased performance and lower manufacturing cost. Improved performance was achieved through optimization of the diffusion recombination losses. A conversion efficiency of 24.2% was achieved on a champion cell made on production equipment...
A preliminary study by Sneddon et al. (2005) using visual working memory tasks coupled with quantified EEG (qEEG) analysis distinguished mild dementia subjects from normal aging ones with a high degree of accuracy. The present study hypothesizes that a simpler task such as having a subject count backwards mentally by ones can be coupled with qEEG to yield a similar degree of accuracy for classifying...
We consider a distributed detection problem over fading multiple-access channels. Sensors observe a phenomenon and transmit their observations to a fusion center using the amplify-and-forward scheme. The fusion center has multiple antennas and uses the transmissions from the sensors to run a detection algorithm. The channels are Ricean fading, and the sensors have no channel information. The performance...
In this paper, we present GaAs MMIC based reconfigurable RF MEMS impedance matching networks for highly integrated (potentially single-chip) frequency-agile LNAs and adaptive multi-band front-ends. Such GaAs MMIC based RF MEMS LNA matching networks have been realized with a frequency tuning range of 40% (10-16 GHz and 15-23 GHz, respectively) and 1-3 dB of in-band losses. Simulated tunable LNA results...
A 16b 160MS/S pipelined ADC built in a complementary SiGe BiCMOS process is presented, with an SFDR of 105dB and an SNR of 77dB at -1dBFS below 160MHz. The fully buffered track-and-hold has circuitry needed to achieve this performance. The internal sub-DAC uses circuits to mitigate the limitations imposed by transistor self-heating, early voltage and impact ionization.
This paper surveys the development of microwave medical imaging and the fundamental challenges associated with microwave antennas design for medical imaging applications. Different microwave antennas used in medical imaging applications such as monopoles, bow-tie, vivaldi and pyramidal horn antennas are discussed. The challenges faced when the latter used in medical imaging environment are detailed...
In most analyses of microstrip patch antennas the effects of a finite ground plane are neglected because it is assumed infinite. However, in mobile communication systems the ground plane of antennas must be finite. Therefore, the effect of the finite ground plane on the characteristics of printed patch antenna elements is worth investigation. In this paper a stacked patch antenna has been proposed...
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