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Maximum directivity of a series-fed microstrip array antenna for wireless application

July 3, 2011
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Conference Paper
Author:
Herbert M. Aumann
…
Published in:
AP-S/URSI 2011, IEEE Antennas and Propagation Society Int. Symp. and USNC/URSI National Radio Science Mtg., 3-8 July 2011, pp. 1327-1330.
Topic:
antennas
R&D area:
R&D group:

Summary

An omnidirectional colinear microstrip array antenna is modeled as a ladder network. A formula is derived for the maximum directivity of a series-fed colinear antenna with an infinite number of ladder sections. It is shown that the maximum directivity is asymptotically limited and depends upon the product of the seriece impedance and shunt admittance of the equivalent ladder network. The result is verified by simulation and experiment.
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Summary

An omnidirectional colinear microstrip array antenna is modeled as a ladder network. A formula is derived for the maximum directivity of a series-fed colinear antenna with an infinite number of ladder sections. It is shown that the maximum directivity is asymptotically limited and depends upon the product of the seriece...

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Maximum directivity of a series-fed microstrip array antenna for wireless application

Distributed multi-modal sensor system for searching a foliage-covered region

April 28, 2011
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Conference Paper
Author:
Matthew R Fetterman
…
Published in:
2011 IEEE Conf. on Technologies for Practical Robot Applications (TePRA), 28 April 2011, pp. 7-14.
Topic:
sensors
R&D area:
R&D group:

Summary

We designed and constructed a system that includes aircraft, ground vehicles, and throwable sensors to search a semiforested region that was partially covered by foliage. The system contained 4 radio-controlled (RC) trucks, 2 aircraft, and 30 SensorMotes (throwable sensors). We also investigated communications links, search strategies, and system architecture. Our system is designed to be low-cost, contain a variety of sensors, and distributed so that the system is robust even if individual components are lost.
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Summary

We designed and constructed a system that includes aircraft, ground vehicles, and throwable sensors to search a semiforested region that was partially covered by foliage. The system contained 4 radio-controlled (RC) trucks, 2 aircraft, and 30 SensorMotes (throwable sensors). We also investigated communications links, search strategies, and system architecture. Our...

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Distributed multi-modal sensor system for searching a foliage-covered region

Overlapped digital subarray architecture for multiple beam phased array radar

April 11, 2011
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Conference Paper
Author:
Jeffrey S. Herd
…
Published in:
EuCAP 2011, 5th European Conf. on Antrennas and Propagation, 11-15 April 2011, pp. 3027-3030.
Topic:
radar
R&D area:
R&D group:

Summary

MIT Lincoln Laboratory is conducting a technology demonstration of affordable Multifunction Phased Array Radar (MPAR) technology for Next Generation air traffic control and national weather surveillance services. Aggressive cost and performance goals have been established for the system. The array architecture and its realization using custom Transmit and Receive Integrated Circuits and panel-based Line Replaceable Unit (LRU) will be presented. A program plan for risk reduction and system demonstration will be outlined.
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Summary

MIT Lincoln Laboratory is conducting a technology demonstration of affordable Multifunction Phased Array Radar (MPAR) technology for Next Generation air traffic control and national weather surveillance services. Aggressive cost and performance goals have been established for the system. The array architecture and its realization using custom Transmit and Receive Integrated...

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Overlapped digital subarray architecture for multiple beam phased array radar

Bioinspired resource management for multiple-sensor target tracking systems

March 7, 2011
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Conference Paper
Author:
Hendrick C. Lambert
…
Published in:
2011 IEEE Aerospace Conf., 5-12 March 2011.
Topic:
sensors
R&D area:
R&D group:

Summary

We present an algorithm, inspired by self-organization and stigmergy observed in biological swarms, for managing multiple sensors tracking large numbers of targets. We devise a decentralized architecture wherein autonomous sensors manage their own data collection resources and task themselves. Sensors cannot communicate with each other directly; however, a global track file, which is continuously broadcast, allows the sensors to infer their contributions to the global estimation of target states. Sensors can transmit their data (either as raw measurements or some compressed format) only to a central processor where their data are combined to update the global track file. We outline information-theoretic rules for the general multiple-sensor Bayesian target tracking problem. We provide specific formulas for problems dominated by additive white Gaussiannoise. Using Cramer-Rao lower bounds as surrogates for error covariances, we illustrate, using numerical scenarious involving ballistic targets, that the bioinspired algorithm is highly scalable and peforms very well for large numbers of targets.
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Summary

We present an algorithm, inspired by self-organization and stigmergy observed in biological swarms, for managing multiple sensors tracking large numbers of targets. We devise a decentralized architecture wherein autonomous sensors manage their own data collection resources and task themselves. Sensors cannot communicate with each other directly; however, a global track...

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Bioinspired resource management for multiple-sensor target tracking systems

Low cost multifunction phased array radar concept

October 12, 2010
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Conference Paper
Author:
Jeffrey S. Herd
…
Published in:
2010 IEEE Int. Symp. on Phased Array Systems, 12 October 2010.
Topic:
radar
R&D area:
R&D group:

Summary

MIT Lincoln Laboratory and M/A-COM are jointly conducting a technology demonstration of affordable Multifunction Phased Array Radar (MPAR) technology for Next Generation air traffic control and national weather surveillance services. Aggressive cost and performance goals have been established for the system. The array architecture and its realization using custom Transmit and Receive Integrated Circuits and a panel-based Line Replaceable Unit (LRU) will be presented. A program plan for risk reduction and system demonstration will be outlined.
READ LESS

Summary

MIT Lincoln Laboratory and M/A-COM are jointly conducting a technology demonstration of affordable Multifunction Phased Array Radar (MPAR) technology for Next Generation air traffic control and national weather surveillance services. Aggressive cost and performance goals have been established for the system. The array architecture and its realization using custom Transmit...

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Low cost multifunction phased array radar concept

Results of X-band electronically scanned array using an overlapped subarray architecture

October 12, 2010
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Conference Paper
Author:
Sean M. Duffy
…
Published in:
2010 IEEE Int. Symp. on Phased Array Systems, 12 October 2010, pp. 713-718.
Topic:
radar
R&D area:
R&D group:

Summary

The measured results from an X-band electronically scanned array using an overlapped subarray architecture are presented. The 2D architecture uses a 12 x 12 element subarray with 3 to 1 overlapping. The active electronic scanned array is a receive only implementation consisting of switch, low noise amplifier, phase shifter and attenuator. Measured far-field patterns and excitation at the aperture using near-field scanner demonstrates desired design goals of a 20 degree sector beam with low sidelobes. Finally, the scan performance of the sector subarray beam is measured at 20 and 40 degrees. A three tile implementation is constructed and measured.
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Summary

The measured results from an X-band electronically scanned array using an overlapped subarray architecture are presented. The 2D architecture uses a 12 x 12 element subarray with 3 to 1 overlapping. The active electronic scanned array is a receive only implementation consisting of switch, low noise amplifier, phase shifter and...

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Results of X-band electronically scanned array using an overlapped subarray architecture

Advanced architecture for a low cost multifunction phased array radar

May 23, 2010
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Conference Paper
Author:
Jeffrey S. Herd
…
Published in:
2010 IEEE/MTT-S Int. Microwave Symp., 23-28 May 2010, pp. 676-679.
Topic:
radar
R&D area:
R&D group:

Summary

MIT Lincoln Laboratory and MIA-COM are jointly conducting a technology demonstration of affordable Multifunction Phased Array Radar (MPAR) technology for Next Generation air traffic control and national weather surveillance services. Aggressive cost and performance goals have been established for the system. The array architecture and its realization using custom Transmit and Receive Integrated Circuits and a panel-based Line Replaceable Unit (LRU) will be presented. A program plan for risk reduction and system demonstration will be outlined.
READ LESS

Summary

MIT Lincoln Laboratory and MIA-COM are jointly conducting a technology demonstration of affordable Multifunction Phased Array Radar (MPAR) technology for Next Generation air traffic control and national weather surveillance services. Aggressive cost and performance goals have been established for the system. The array architecture and its realization using custom Transmit...

READ MORE
Advanced architecture for a low cost multifunction phased array radar

Multifunction phased array radar (MPAR) for aircraft and weather surveillance

May 10, 2010
  |
Conference Paper
Author:
Jeffrey S. Herd
…
Published in:
2010 IEEE Radar Conf., 10 May 2010.
Topic:
radar
R&D area:
R&D group:

Summary

MIT Lincoln Laboratory and M/A-COM are jointly conducting a technology demonstration of affordable Multifunction Phased Array Radar (MPAR) technology for Next Generation air traffic control and national weather surveillance services. Aggressive cost and performance goals have been established for the system. The array architecture and its realization using custom Transmit and Receive Integrated Circuits and a panel-based Line Replaceable Unit (LRU) will be presented. A program plan for risk reduction and system demonstration will be outlined.
READ LESS

Summary

MIT Lincoln Laboratory and M/A-COM are jointly conducting a technology demonstration of affordable Multifunction Phased Array Radar (MPAR) technology for Next Generation air traffic control and national weather surveillance services. Aggressive cost and performance goals have been established for the system. The array architecture and its realization using custom Transmit...

READ MORE
Multifunction phased array radar (MPAR) for aircraft and weather surveillance

Integrated compensation network for low mutual coupling of planar microstrip antenna arrays

June 9, 2007
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Conference Paper
Author:
Sean M. Duffy
…
Published in:
IEEE Antennas and Propagation Society Int. Symp., 2007 Digest, 9-15 June 2007, pp. 1273-6.
Topic:
antennas
R&D area:
R&D group:

Summary

The unavoidable presence of mutual coupling of antenna elements in an array limits the ability to transmit and receive signals concurrently [1]. In the absence of mutual coupling, it is conceivable although still difficult to transmit and receive at the same frequency at the same time, i.e., FM-CW radars. The reflection from the antenna, leakage through the circulator, and any other possible deleterious paths from the high power amplifier to the low noise amplifier must be cancelled or compensated for in some manner to keep the receiver linear. With a single antenna the signal and noise paths are correlated and therefore cancellation of the signal inherently eliminates the noise. However, in an array environment the mutual coupling of antenna elements cause noise from neighboring high power amplifiers to couple into each channel's receiver. While the signal coupling is coherent, the noise is uncorrelated to a degree that depends on the amplifier gain and noise figure. The use of a low mutual coupling antenna array is a critical element in operating systems in this manner.
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Summary

The unavoidable presence of mutual coupling of antenna elements in an array limits the ability to transmit and receive signals concurrently [1]. In the absence of mutual coupling, it is conceivable although still difficult to transmit and receive at the same frequency at the same time, i.e., FM-CW radars. The...

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Integrated compensation network for low mutual coupling of planar microstrip antenna arrays

Ultra-wideband step notch array using stripline feed

June 9, 2007
  |
Conference Paper
Author:
Glenn A. Brigham
…
Published in:
IEEE Antennas and Propagation Society Int. Symp., 2007 Digest, 9-15 June 2007, pp. 3361-4.
Topic:
antennas
R&D area:
R&D group:

Summary

Electronically scanned array (ESA) antennas capable of efficiently radiating over an octave of bandwidth provide system designs with more flexibility in multiple mode operation. Communication and radar bands occupy different frequency allocations and the growing research in Ultra-Wideband (UWB) communications make the use of a single ESA to cover these frequencies an area of interest. Array antennas constructed of tapered-slot antennas and TEM horns have been investigated and shown to operate successfully over an octave bandwidth. These antennas use vertical feeds which make them optimal for brick architectures, but less than desirable for tile architectures. Conventional notch antennas require a feed extending vertically away from the notch antenna which makes a flat 2-D connection between antennas difficult. In this work an Ultra-Wideband Step Notch Array (UWSNA) was designed for ESA applications. The array operates over a 6-12 GHz range using a flat, tile-based 2-D feed network making this array optimal for conformal applications with a minimum of vertical distance. Simulation results and measurements on a small prototype demonstrate the concept.
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Summary

Electronically scanned array (ESA) antennas capable of efficiently radiating over an octave of bandwidth provide system designs with more flexibility in multiple mode operation. Communication and radar bands occupy different frequency allocations and the growing research in Ultra-Wideband (UWB) communications make the use of a single ESA to cover these...

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Ultra-wideband step notch array using stripline feed
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