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The performance of superdirective beamforming of a practical circular hydrophone array is investigated. The received signal of a 16-element circular hydrophone array with radius of 0.25m are measured in the anechoic water tank. The array manifold at the frequency of 1.11kHz is obtained. The superdirective beamforming of the circular array is designed and realized. The correctness and effectiveness...
A method for on-chip extraction of random telegraph noise (RTN) parameters from transistors is proposed. Exploiting the nature of exponential distributed RTN events, the proposed circuit enables the automatic extraction of mean RTN time constants from a large array of small-area transistors. The on-chip data processing provides a simplified measurement infrastructure, reduces the measurement time...
A wireless system-on-chip with integrated antenna, power harvesting and biosensors is presented that is small enough, 200µm × 200µm × 100µm, to allow painless injection. Small device size is enabled by: a 13µm × 20µm 1nA current reference; optical clock recovery; low voltage inverting dc-dc to enable use of higher quantum efficiency diodes; on-chip resonant 2.4GHz antenna; and array scanning reader...
Cumulative distribution functions (CDFs) for multiple-input-multiple-output (MIMO) capacities are computed for flat-fading indoor channels at 5.8 GHz. These CDFs are based on two measured channels and on reconstructions of the MIMO channels from path parameters that are estimated based on measured data. The measured data was obtained using the stepped-frequency method of channel sounding in combination...
A method of measuring the echo reduction of passive materials based on inverse filtering technique is presented. In this method, a received signal which contains circuit channel and underwater acoustic channel information is obtained by transmitting the initial pilot signal and receiving signals through the hydrophone. With inverse filtering technique, the channel transfer function between the transducer...
Bartlett estimator is a widely used objective function in matched field inversion (MFI) to quantify the misfit between measured acoustic field and replica field. In this paper, under the assumption of additive spatially correlated Gaussian residual errors, a normalized covariance weighted Bartlett estimator is employed in geoacoustic inversion as the objective function utilizing global optimization...
An X-band FMCW sensor is developed with beam-scanning capability to reliably detect the vehicles with different shapes. Two-element transmitting antenna array is designed with single phase shifter and an unequal power divider to reduce the cost and achieve compact size of 4.5 cm × 4 cm. Experiments successfully confirm precise identification of the incoming vehicle and its occupancy.
In the research project, a design concept of the mm-wave antenna array operating at 38 GHz is proposed by using a 64-element micorstrip patch antenna array. Theoretical and experimental study validates the design approach for the use of the Fifth generation (5G) wireless communication system.
We present here two linear arrays mounted in the same aperture: the first array with 4 elements at 2.7 GHz (spacing 0.7λ) and the second array with 4 elements at 7.0 GHz (spacing 1.8λ). It is shown that by special design of the single high frequency element grating lobes are eliminated. The isolation between the two arrays is better than 14 dB.
This paper deals with spatio-temporal analysis. The measurement of the directions of arrival using an antennas array is limited by the number of detected sources. In a linear network of M antennas, the maximum number of not correlated signals that can be localized is (M-1), and (2M/3) in case of correlated signals. Thus, the number of antennas must be higher than the number of signals. The spatio-temporal...
In this paper the design and the implementation of a cavity antenna array in PCB technology for automotive radar applications is presented. The array consists of four cavity antennas fed by a microstrip-line feeding network and H-shaped coupling apertures in the ground plane. Simulation and measurement results show that the proposed structure is a suitable candidate for the integration in automotive...
This paper reports a high-performance low-power and area-efficient single-ended SAR ADC for neural signal acquisition. The proposed 10-bit ADC features a novel symmetrical DAC switching technique that resolves the signal-dependent comparator offset voltage problem in conventional single-ended SAR ADCs, and improves the ADC's ENOB. Combined with an existing LSB single-sided switching method, the proposed...
A low cost 3-element sectorial fermi taper slot antenna configuration with sin-corrugation is designed at 28GHz. The elements can be illuminated individually based on the direction of the transmitter. In the proposed antenna structure each element produces a high gain of 15dB, a wide impedance bandwidth, a side-lobe levels less than -12.5dB, and an overall line of sight beam-width of +45 degrees....
Knowledge of the Direct-to-Reverberant Ratio (DRR) and Reverberation Time (T60) can be used to better perform speech and audio processing such as dereverberation. Established methods compute these parameters from measured Acoustic Impulse Responses (AIRs). However, in many practical situations the AIR is not available and the parameters must be estimated non-intrusively directly from noisy speech...
An RF Phased array can steer the direction of the beam electronically and it brings about benefits in terms of signal to noise ratio (SNR) and directivity. However, testing the phased array generally requires expensive and high performance RF equipment. This increases production test cost and hampers in-field calibration. We present a low-cost, self-compensating Built-In Self-test (BIST) and calibration...
A likelihood function for a multi-sensor, passive sonar Bayesian tracker may use data directly from the array elements or, alternatively, from the output of a conventional beamformer (CBF). Here, we compare the performance of a Bayesian tracker when using element- versus CBF-level data. We observed that, provided the CBF's beams are sufficiently closely spaced, the tracker's performance with CBF-level...
A novel antenna measurement strategy has been developed to characterize both the embedded-element and the array patterns in the real installation conditions at low frequencies (50 MHz – 650 MHz) [1]. It exploits a micro
Recent experimental results for the sensitivity of aperture arrays at room temperature show 40 K array noise temperatures over the frequency range from 1000 MHz to 1500 MHz. Further reduction of array noise temperature is important to comply with the SKA sensitivity requirements at affordable cost. Furthermore the frequency range should be extended to a lowest frequency of 500 MHz, in order to meet...
Stacked dielectric resonator antenna from high-k low loss bulk-glass ceramic material have been investigated. Two resonators are stacked with an air gap which has been realized with a low loss foam material. The antenna showed a wide bandwidth with the dimension of 7.7×6.7×2.5mm for the lower dielectric resonator and 8.7×7.7×3.3mm for the upper dielectric resonator. Thus the maximum dimension is 0...
Recent works have demonstrated the feasibility of microwave imaging using compressive techniques, exempting the use the of active delay lines, phase shifters, or moving parts to achieve beamforming. With this method, waves are coded in a passive way by a compressive device to reduce the complexity of the transmitter and/or receiver chains of the telecommunication and radar systems requiring beamsteering...
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