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The first modular 4-channel frontend for exploring phased array communications at a carrier frequency of 300 GHz was developed. A metamorphic HEMT process with a gate length of 35 nm was the key enabling technology for the integration of each transmit and receive channel. All channels implemented the quadrature direct conversion architecture. The measured RF bandwidth exceeded 55 GHz for the receive...
Future communication links will require higher data rates, multiple beams, and higher transmit/receive gains, in addition to smaller weight, cost, and power. With the growing interest for reduced size platforms and the requirement for ultra-wideband (UWB) performance to address multifunctionality, there is a strong need for UWB apertures to enable increased spectral efficiency, multifunctionality...
This paper proposes a method to detect photon counts from a commercial off-the-shelf SPAD array. Experiments show that using this method the sensitivity of a VLC receiver that incorporates this SPAD array approaches the limit set by Poisson noise.
In this paper, a beamforming system for LTE- Advanced based on Array sampling technology is proposed. Antenna Array that has been designed covers LTE mid and high bands. RF multiplexer 8x1 switch has been designed and simulated. The system is composed of agile RF frontend and FPGA digital signal processing unit.
This paper describes a 28GHz CMOS direct conversion transceiver with packaged 2×4 patch antenna arrays for 5G communication. Test results show good RF performances of Rx NF 6.7dB, Maximum Tx EIRP 31.5dBm (1PA Pout_sat =10.5dBm), LO integrated phase noise −37.8dBc (0.67°), Rx/Tx EVM around 2.2% (−33.1dB) at mid RF power, and well-fitted beam control capability.
This paper introduces a real-time multiple input and multiple output (MIMO) channel sounder to measure the vehicle-to-vehicle (V2V) propagation channel at 5.9 GHz. Compared to the existing V2V channel sounders, our design emphasizes on improving the stability of the setup and increasing the MIMO snapshot rate. The system stability allows us to develop a high resolution parameter extraction algorithm...
This paper describes a new form of the wideband, wide scan notch array antenna which provides some distinct advantages. The Planar-Fed Folded Notch (PFFN) Array described herein differs from more traditional printed circuit board (PCB) and metal embodiments of the notch radiator array. PFFN array designs employ planar feeds that are incorporated on a single, common multi-layer PCB that is parallel...
Digital array radars (DAR) with element-level digital transmission and reception present new opportunities for more advanced radar functionality and performance. In order to reduce RF front-end complexity while also reducing the need for high sample rates, the analog IQ demodulation receiver, or homodyne, is proposed so that only a single local oscillator (LO) is needed per element. An important homodyne...
In this paper we propose an adaptive multi user (MU) single-cell hybrid precoding strategy that iteratively designs the precoders/combiners exploiting the reciprocity of time division duplex (TDD) millimeter wave systems. The minimum mean square error (MMSE) criterion is considered to design the combiners, which relies on second order statistics of the channel. The covariance of the received signal...
Matrix computations are a fundamental tool in scientific and engineering applications. Among many such applications, Convolutional Neural Networks (CNN) that can be effectively computed by matrix-matrix multiplications are being popular and an efficient implementation of CNN is highly important. In this study, we have designed an parallel processor for the matrix computations using torus interconnect...
To do the radiation emission measurement in RF integrated system, near-field measurement method was adopted. As near-field data is a relative value, far-field data was needed and the study of the conversion problem from near-field to far-field was required. In this paper a method, based on an array of dipoles, was proposed to model equivalent interference sources through using regularization technique.
Amplitude comparison is an efficient method to find the direction of arrival (DOA) of a radio frequency (RF) emitter. However, the DOA accuracy obtained by this method is usually poor due to beam pattern distortion. This paper provides a localization and beam pattern auto-calibration method, which estimates a RF emitter position and antenna beam pattern distortion simultaneously. The problem is formulated...
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.
Demonstration of low conversion loss through the novel integration and packaging of high power photodiodes and a fragmented aperture antenna for a fiber-fed RF array.
We evaluated how magnetic resonance imaging robustness depends on dual-row transmit array geometry, head size, position of a head inside the array and array tuning condition. A clear winner was not found. For overlapped arrays, different tuning conditions resulted in larger peak-to-peak variation for circular polarization excitation, but B1+ (averaged over the volume of interest) decrease was as a...
This work establishes a state-of-the-art protective measure on how the smart antennas can be used effectively to curtail the activities of hackers/intruders on radio frequency signals. Hackers can scan confidential information/data belonging to organization, law enforcement and even interception of radio frequencies signals to the public usage. In this analysis, three antenna elements array have been...
For high and ultrahigh field MRI applications, parallel imaging that employs multi-channel RF coil arrays has been developed in order to reduce data acquisition time and to manipulate the Bi distribution by enabling RF shimming. However, implementing parallel imaging or parallel excitation still is considered a significant challenge in terms of high electromagnetic coupling among closely placed resonant...
A continuous-time low-pass sigma-delta modulator (ΣΔM) with a chain of integrators and weighted capacitive feedforward (CICFF) summation topology is fabricated by tsmc 0.18 um CMOS process. This proposed including health transducer with wireless charging and WuRx front-end on tracheostomy tube for microsystems technology in hospital. The summation of feedforward signals is implemented by the weighted...
This paper presents an integrated Ka-band 2×2 True-Time-Delay (TTD) phased array receiver using a 0.25nm SiGe:C BiCMOS technology. Each phased array receiver channel is able to perform 20.5 ps variable delay as well as 6 dB variable gain. A mixer and buffer are integrated to down-convert the RF signal into a fixed IF1 at 11 GHz. Each receiver channel presents more than 20 dB RF-IF1 conversion gain...
We demonstrate waveguide integrated pin-photodiode arrays (WG-PDAs) by optically parallel connection of different numbers of photodiodes. A responsivity of 0.53A/W is achieved at 1550nm. At 40GHz, the WG-PDA chips with a 4-photodiode array show a RF output power of 10dBm and an OIP3 value of 26dBm. The WG-PDA chips with a 3-photodiode array generate a RF output power of 7.1dBm, 6.3dBm, 3.6dBm and...
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