Element-Level Digital Communications Array
PROGRAM: PEO Integrated Warfare Systems (IWS) 6.0 Command & Control (C2)
technology within this topic is restricted under the International Traffic in
Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and
import of defense-related material and services, including export of sensitive
technical data, or the Export Administration Regulation (EAR), 15 CFR Parts
730-774, which controls dual use items. Offerors must disclose any proposed use
of foreign nationals (FNs), their country(ies) of origin, the type of visa or
work permit possessed, and the statement of work (SOW) tasks intended for
accomplishment by the FN(s) in accordance with section 3.5 of the Announcement.
Offerors are advised foreign nationals proposed to perform on this topic may be
restricted due to the technical data under US Export Control Laws.
Develop a digital, C-Band Transmit (Tx) and Receive (Rx) array antenna that
transmits and receives multiple spatially and spectrally diverse narrowband
Expanded mission areas and the implementation of additional data routing
resulting from future warfighting capabilities place more demand on data
distribution services in the form of higher data bandwidths and reduced
latencies. These demands require improvements in Radio Frequency (RF) spectrum
utilization and advances in antenna technologies. Digital array antenna
technology promises to enable these improvements by dramatically increasing
operational flexibility. Digital arrays are not off the shelf available; but
rather, industry contractors develop digital arrays in response to acquisition
efforts. The commercial development of multi-beam 5G networks will focus on
small picocells. Lower power levels and reduced linearity challenge leave a
significant gap preventing commercial technology from being useful in Navy
applications. Defense Advanced Research Projects Agency (DARPA) efforts have
made digital arrays a more off the shelf technology. Notable among these is the
Arrays at Commercial Time Scales (ACT) and Millimeter-wave Digital Arrays
(MIDAS) program. These programs focus on the transceiver and beamforming
functionality of the array as opposed to the aperture. However, this technology
is still not off the shelf and integration work would be required to meet the
digital array needs even using this technology. The Navy must overcome some
technology risks with a critical one being the development of digital array
technology that can operate at the necessary bandwidths and frequencies while
in complex RF environments.
The Navy seeks to expand and refine the battlespace by improving and expanding
tactical network functionality. Increased data throughput is needed to enable
the flow of more data and support of new mission areas. Decreased latency is
needed to enable new and compressed kill chains against advancing threats as
well as larger networks. Increased network throughput and decreased latency
will be attained by developing 4-channel Transmit (Tx) and Receive (Rx)
capability for digital communications arrays. The level of improvement in the
fielded system will depend on the topology, size, and operation of the
network. For large, half-duplex (i.e., cannot transmit and receive
simultaneously) networks of four-beam nodes having all nodes connected along a
line, the level of throughput improvement will approach a factor of 2. For
large, half-duplex networks of four-beam nodes having topologies where all the
nodes are connected to each other, the throughput improvement will approach a
factor of 4. For other networks, the improvement will be somewhere in between.
Of course, the fielded system may have a different number of beams per node.
Four was chosen based on engineering judgement as a compromise between
complexity, technical challenge, and capability improvement.
The Navy needs a digital communications array to realize simultaneous,
multichannel Tx and Rx capability. The digital communications array is a key
enabler for higher data throughputs and reduced latency needed to engage
evolving threats and enabling significant improvement in utilization of
spectrum. This must be done while pushing the boundaries of signal integrity,
dynamic range, isolation of signals and resistance to interference to maximize
link performance. No technology currently meets all these requirements.
An innovative digital antenna subarray architecture is sought to attain the
previously stated requirements. More specific antenna system goals include a 1
x 4 linear configuration and element level signal generation and digitization.
Beam steering in azimuth should be ±60º. The subarray should transmit and
receive 4 simultaneous beams in half duplex mode. The operational bandwidth is
C-band (4 GHz to 8 GHz). Compared to the operational bandwidth, the
instantaneous bandwidth is relatively narrow. The element level Equivalent
Isotropic Radiated Power (EIRP) should be 0 dBW over the scan volume. The
output Error Vector Magnitude (EVM) should be less than 3%. The antenna should
be able to receive an incident signal with incident power density measured at
the free-space-to-antenna interface ranging from -134 dBW to -53 dBW and output
a digital signal with 20 dB signal to interference plus noise ratio. The goal
for the spur free dynamic range is 80 dB. 32 dBm is the goal for the input
third order intercept. The polarization should be selectable, with four
options. These options should be horizontal, vertical, right hand circular and
left hand circular. The polarization loss factor should be less than 0.25 dB.
The antenna will be capable of null steering with a null depth goal of 80 dB
relative to the mainlobe.
The subarray must be capable of processing 4 narrowband signals located
arbitrarily within a contiguous operational bandwidth within C-band. The design
should permit any two 1 x 4 subarrays to be connected in any configuration and
beam-steered. A two-dimensional array must be capable of having its beam
steered in both dimensions. The design should permit connecting 1 x 4 or 4 x 1
subarrays into a contiguous rectangular array of arbitrary size. For example,
three 1 x 4 subarrays must be able to be configured to form a 1 x 12 and then
reconfigured to form a 3 x 4; without re-flashing firmware. Moreover, both
configurations must demonstrate vertical, horizontal, right-hand circular, and
left-hand circular polarizations while attaining 0.25 dB of polarization loss
factor for each of these four polarizations. The design should include built-in
testing to indicate failures that occur. The interface to the digital array on
the transceiver side will use a standard format to send digits of data, such as
Ethernet. Beam steering commands sent to the array will contain azimuth and
elevation angles relative to the array face, frequency and Tx or Rx
Testing, evaluation, and demonstration should include configuring and measuring
antenna patterns for a 1 x 12 and 3 x 4 array using the same three (3) 1 x 4
subarrays. Moreover, vertical, horizontal, right-hand circular, and left-hand
circular polarizations should be demonstrated. Validation of the prototype
will be through comparison of model predictions to measured performance. The
location for the demonstration may occur at the small business’s facility or at
a Government-identified location.
Work produced in Phase II may become classified. Note: The prospective
contractor(s) must be U.S. Owned and Operated with no Foreign Influence as
defined by DOD 5220.22-M, National Industrial Security Program Operating
Manual, unless acceptable mitigating procedures can and have been be
implemented and approved by the Defense Security Service (DSS). The selected
contractor and/or subcontractor must be able to acquire and maintain a secret
level facility and Personnel Security Clearances, in order to perform on
advanced phases of this contract as set forth by DSS and NAVSEA in order to
gain access to classified information pertaining to the national defense of the
United States and its allies; this will be an inherent requirement. The
selected company will be required to safeguard classified material IAW DoD
5220.22-M during the advance phases of this contract.
Define and develop a concept for a digital C-Band Tx and Rx array antenna.
Demonstrate that the concept can feasibly meet the Navy requirements as
provided in the Description. Establish feasibility by a combination of initial
analysis and modeling. The Phase I Option, if exercised, will include the
initial design specifications and capabilities description to build a prototype
in Phase II.
Develop and deliver a prototype digital C-Band Tx and Rx array antenna that
demonstrates the performance parameters outlined in the Description. Conduct
prototype testing, evaluation, and demonstration (at the small business’s
facility or at a Government-identified location). Provide an interface control
document guide for developing the signal and control interface for the array.
Include configuring and measuring antenna patterns for a 1 x 12 and 3 x 4 array
using the same three (3) 1 x 4 subarrays in the demonstration plus vertical,
horizontal, right-hand circular, and left-hand circular polarizations. Validate
the prototype through comparison of model predictions to measured performance.
It is probable that the work under this effort will be classified under Phase
II (see Description section for details).
DUAL USE APPLICATIONS: Support the Navy in transitioning the technology for
Navy use. Further refine the prototype for evaluation to determine its
effectiveness and reliability in an operationally relevant environment. Support
the Navy in the system integration and qualification testing for the technology
through platform integration and test events to transition the technology into
PEO IWS 6 applications for simultaneous communications links to improve and
expand tactical network functionality.
Digital, high-performance antennas will have direct application to private
sector industries that involve directional communications between many small
nodes over large areas. These applications include transportation, air traffic
control, and communication industries.
Roger, McAllister, John, Lightbody, Gaye and Yi, Ying. “FPGA-based
Implementation of Signal Processing Systems. 2nd ed.” John Wiley & Sons,
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Robert J. “Phased Array Antenna Handbook. 2nd ed.” Artech House, Inc.: Norwood,
MA, 2005. https://pdfs.semanticscholar.org/2a93/5a6beae90d9f30e1cf1ef5c17b168456e1b0.pdf
Qizheng. “RF System Design of Transceivers for Wireless Communication.”
Springer Science+Business Media, LLC.: New York, NY, 2005. https://pdfs.semanticscholar.org/d836/c0f72a23aa543826975e4bcf71564c051963.pdf
Digital Array; Communications Array; Multichannel Tx and Rx; Digital Antenna
Subarray Architecture; Narrowband Signals; Digital Antenna Subarray