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Unmanned aircraft sense and avoid radar: surrogate flight testing performance evaluation

Summary

Unmanned aircraft systems (UAS) have proven to have distinct advantages compared to manned aircraft for a variety of tasks. Current airspace regulations require a capability to sense and avoid other aircraft to replace the ability of a pilot to see and avoid other traffic. A prototype phased-array radar was developed and tested to demonstrate a capability to support the sense and avoid (SAA) requirement and to validate radar performance models. Validated radar models enable evaluation of other radar systems in simulation. This paper provides an overview of the unique radar technology, and focuses on radar performance and model validation as demonstrated through a flight testing campaign. Performance results demonstrate that the prototype SAA radar system can provide sufficient accuracy to sense avoid non-cooperative aircraft.
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Summary

Unmanned aircraft systems (UAS) have proven to have distinct advantages compared to manned aircraft for a variety of tasks. Current airspace regulations require a capability to sense and avoid other aircraft to replace the ability of a pilot to see and avoid other traffic. A prototype phased-array radar was developed...

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Multi-lithic phased array architecture for airborne sense and avoid radar

Summary

Transmit and receive Ku-band phased array designs are described for testing an airborne sense and avoid radar. The arrays are small with a size of 24 cm x 9 cm and operate from 13 to 17 GHz with electronic scanning from plus of minus 45 degrees in azimuth and plus of minus 30 degrees in elevation. A novel design architecture allows the use of multiple multilayered printed circuit boards and simple air cooling.
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Summary

Transmit and receive Ku-band phased array designs are described for testing an airborne sense and avoid radar. The arrays are small with a size of 24 cm x 9 cm and operate from 13 to 17 GHz with electronic scanning from plus of minus 45 degrees in azimuth and plus...

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Stepped notch antenna array used as a low thermal resistance heat sink

Summary

A stepped notch antenna at Ku-band is developed to provide a thermal heat sink for active arrays. The antenna with forced air cooling provides up to 0.4 degrees C/W of thermal resistance. The antenna integration with a printed circuit board allows for high volume surface mount assembly of active devices.
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Summary

A stepped notch antenna at Ku-band is developed to provide a thermal heat sink for active arrays. The antenna with forced air cooling provides up to 0.4 degrees C/W of thermal resistance. The antenna integration with a printed circuit board allows for high volume surface mount assembly of active devices.

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Multifunction phased array radar (MPAR) spectral usage analysis

Published in:
MIT Lincoln Laboratory Report ATC-395

Summary

This report addressed two technical risks associated with replacing current air traffic and weather surveillance radars with a single type of multifunction phased array radar (MPAR). The first risk is whether radio spectrum usage would increase with the MPAR network and whether the allocated band will have enough spectral space. This question is addressed in two steps. First, single-radar spectrum usage is estimated based on certain assumptions regarding the radar design. Second, locations based on a previous radar placement study are used together with a terrain-dependent propagation model to compute the number of frequency channels needed at each site. We conclude that the overall spectrum usage is likely to increase with MPAR, but that the targeted window in S band will be able to accommodate the occupancy at all sites. The second risk is whether self-interference will limit the ability of the MPAR to operate asynchronously and adaptively on different antenna faces. This question is addressed by employing a simple bistatic ground clutter model to characterize the interference between adjacent faces. We conclude that some interference is unavoidable, but it would likely only occur during times when a transmit beam is at its maximum off-broadside angle (~2% of the time).
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Summary

This report addressed two technical risks associated with replacing current air traffic and weather surveillance radars with a single type of multifunction phased array radar (MPAR). The first risk is whether radio spectrum usage would increase with the MPAR network and whether the allocated band will have enough spectral space...

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Overlapped digital subarray architecture for multiple beam phased array radar

Author:
Published in:
EuCAP 2011, 5th European Conf. on Antrennas and Propagation, 11-15 April 2011, pp. 3027-3030.

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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Low cost multifunction phased array radar concept

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

Published in:
2010 IEEE Int. Symp. on Phased Array Systems, 12 October 2010, pp. 713-718.

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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Advanced architecture for a low cost multifunction phased array radar

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...

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

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

Published in:
IEEE Antennas and Propagation Society Int. Symp., 2007 Digest, 9-15 June 2007, pp. 1273-6.

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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