skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


Title: Mobile Sensor Location Optimization U sing Support Vector Machines with Error-Correcting Output Codes
This work is concerned with the introduction and development of a technique to optimally position a Mobile Sensor (MS) in a location with adequate side lobe Radio Frequency (RF) signal power. The proposed method involves the generation of a database (DB) of side lobe power distribution for different azimuth angles of the downlink transmitted signal. The generated DB is subsequently used to train and test a Machine Learning (ML) multiclass classifier, as well as two distinct Convolution Neural Networks (CNN), to identify the desired MS location. Simulation experiments are performed which indicate a maximum accuracy of 99.25%, 96.56% and 96.10% for 8 different receiver locations.  more » « less
Award ID(s):
1822087
PAR ID:
10183031
Author(s) / Creator(s):
; ;
Publisher / Repository:
IEEE
Date Published:
Journal Name:
2nd World Symposium on Communication Engineering (WSCE)
Page Range / eLocation ID:
157 to 163
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. (, ICC 2021 - IEEE International Conference on Communications)
    null (Ed.)
    In this paper, MPCast, a novel wireless transmission technology for the downlink of Low Power Wide Area Networks (LPWAN), is proposed. MPCast modulates data on the Zadoff-Chu (ZC) sequence, which generates a peak at the receiving side. Both the location and phase of the peak carry information. Also, multiple peaks are transmitted simultaneously at different power levels to be received by nodes with different channel conditions. A novel preamble design allows the nodes to detect the frame and synchronize with the AP at low computation complexity. MPCast has been validated with real-world experiments on the Powder platform. MPCast has also been evaluated with simulations under a challenging wireless channel model. The results show that MPCast achieves a physical layer data rate of 1.74 kbps in a 125 kHz channel when the Signal to Noise Ratio (SNR) is -7 dB, which is a 9 dB gain over LoRa SF 9. 
    more » « less
  2. ; ; ; (, Optics Express)
    Bragg-grating based cavities and coupler designs present opportunities for flexible allocation of bandwidth and spectrum in silicon photonic devices. Integrated silicon photonic devices are moving toward mainstream, mass adoption, leading to the need for compact Bragg grating based designs. In this work we present a design and experimental validation of a cascaded contra-directional Bragg-grating coupler with a measured main lobe to side-lobe contrast of 12.93 dB. This level of performance is achieved in a more compact size as compared to conventional apodized gratings, and a similar design philosophy can be used to improve side-lobe reduction in grating-based mirror design for on-chip lasers and other cavity-based designs as well. 
    more » « less
  3. ; ; ; ; ; (, IEEE Transactions on Microwave Theory and Techniques)
    This article presents a back-off efficient power amplifier (PA) for mm-wave 5G and upcoming 6G beamforming phased array transceivers (PATs), incorporating advanced circuit designs and novel implementations in both passive and active components. Conventional back-off efficient PAs in the mm-wave frequency range occupy a large chip area, making it hard to fit them into PATs. To overcome this issue, we propose a compact back-off efficient Doherty PA (DPA) with a common base (CB) structure as the core of the PA and small low-loss passive elements. In addition, the proposed architecture moves the role of the input hybrid coupler to the interstage matching network while maintaining DPA functionality. The interstage matching provides the required phases for the main and auxiliary PAs, power division, and impedance matching. The PA prototype is fabricated in the GlobalFoundries 90-nm BiCMOS (9 HP) process. It achieves a peak gain of 20.4 dB at 28.45 GHz with a 1-dB bandwidth of 4.45 GHz. Under large-signal conditions, it archives >19.5-dBm Psat with >36% PAEsat. Its P1dB at 26, 28, and 30 GHz are 19.4, 19.3, and 19.3 dBm with 38.5%, 37.3%, and 36.8% PAE1 dB, respectively. In the 6-dB power back-off region, it reaches efficiencies of 29.1%, 31.1%, and 29.3% at 26, 28, and 30 GHz, respectively. When tested with the NR-FR2 test model at these frequencies, the PA achieves Pavg of 8.25, 8.45, and 8 dBm, and PAEavg of 13.9%, 14.5%, and 13.7% for a 400 M 1-CC 64-QAM signal, maintaining an rms error vector magnitude (EVMrms) of −25.8, −25.8, and −25.7 dB. In addition, in adjacent channel power ratio (ACPR) tests, the PA achieves −27, −26.2, and −30.8 dBc on the lower side and −28.4, −28.5, and −27.6 dBc on the higher side channels at 26, 28, and 30 GHz, respectivelyNot Available 
    more » « less
  4. ; ; ; ; ; ; ; (, Optics Express)
    Optical phased arrays (OPAs) which beam-steer in two dimensions (2D) are currently limited to grating row spacings well above a half wavelength. This gives rise to grating lobes along one axis which limit the field of view (FOV), introduce return signal ambiguity, and reduce the optical efficiency in lidar applications. We demonstrate a Vernier transceiver scheme which uses paired transmit and receive phased arrays with different row periodicities, leading to mismatched grating lobe angular spacings and only a single aligned pair of transmit and receive lobes. This permits a return signal from a target in the desired lobe to be efficiently coupled back into the receive OPA while back-scatter from the other grating lobes is rejected, removing the ambiguity. Our proposal goes beyond previously considered Vernier schemes in other domains like RF and sound, to enable adynamic Vernierwhere all beam directions are simultaneously Vernier aligned, and allow ultra-fast scanning, or multi-beam, operation with Vernier lobe suppression. We analyze two variants of grating lobe suppressing beam-steering configurations, one of which eliminates the FOV limitation, and find the conditions for optimal lobe suppression. We present the first, to the best of our knowledge, experimental demonstration of an OPA Vernier transceiver, including grating lobe suppression of 6.4 dB and beam steering across 5.5°. The demonstration is based on a pair of 2D-wavelength-steered serpentine OPAs. These results address the pervasive issue of grating lobes in integrated photonic lidar schemes, opening the way to larger FOVs and reduced complexity 2D beam-steering designs. 
    more » « less
  5. ; (, 2019 IEEE International Symposium on Phased Array System & Technology (PAST))
    null (Ed.)
    This paper presents the grating lobe reduction in a planar phased array antenna with a rectangular lattice and large element spacing in the order of one wavelength for scan angles up to ±45°. A dual-mode circular microstrip patch antenna is considered as the constitutive element of the phased array, in which two different transverse magnetic modes are exploited simultaneously. The numerical analysis shows that the achieved grating lobe reduction is well below 25 dB for scan angles up to ±45° with large element spacing in the order of one wavelength. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email