APPENDIX D
Statement of Work
For the purchase and the installation of absorber material in
the Spherical Near-Field chamber AND the refurbishment of
the Compact antenna shielded chamber
1. Background
The Communications Research Centre (CRC) is actively designing antennas, antenna systems,
subsystems and other high frequency antenna systems and associated subsystem components to
support operational and research activities. To assist and to validate new designs a near-field
(NF) system has been setup in an anechoic chamber in building 2F AND a large Compact
antenna chamber for far-field (FF) measurement at 3701 Carling Avenue, Ottawa location. The
NF anechoic chamber is a large free standing aluminum structure with no ceiling and three
operative doors (2 on front wall, 1 on rear wall) housing a Near Field System (NSI) Spherical
scanner. This NF chamber measures 144” x 168” x 146” and is currently lined with 8-18 inch
pyramidal, microwave absorber. This Velcro attached absorber requires replacement due to the
age and electromagnetic performance at frequencies associated with GPS activities, military
tactical communications, SATCOM bands, and radar bands. The measurement performance shall
be of extremely high quality, sufficient to demonstrate device compliance with existing standards
and/or client driven design requirements. The Compact antenna chamber is much larger fully
shielded free standing chamber measuring 30Ft long x 20Ft wide x 20Ft high. This chamber is
lined with high performance 12 inch pyramidal microwave absorber and houses a compact range
reflector, feed tower and multi-axis test positioners. This chamber requires refurbishment to
repair the water damaged shielding panels and microwave absorber panels located on the ceiling
of the chamber. All microwave absorber panels are secured to the shielded panel using a high
strength water based contact adhesive approved for polyurethane foam. A nylon safety netting is
installed used to prevent absorber panels from falling from the ceiling. As well, many strategic
sections of shielding panels are secured to a steel superstructure surrounding the chamber.
2. Objective
This contract is organized into two parts. The first part deals with the replacement of the existing
absorber on the walls and the floor of the NF chamber, and on the NSI NF positioners, towers
with new high performance absorbers facilitating high fidelity measurements from 0.5 GHz to 40
GHz.
The successful contractor will be required to remove the existing absorber and to design,
fabricate, deliver, install, test and warranty the absorber installation, and performance as outline
in the specifications. The existing absorber shall be disposed using standard disposal methods as
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required by local, provincial and national regulations. The design of the new absorber installation
shall be optimized to provide minimum peak to peak amplitude ripple within the antenna test
volume. This requires that the reflected E field be a minimum of -60dB below the desired
transmit signal at 1 GHz. Using the free space attenuation, and absorber reflectivity performance
levels, a -60dB can be achieved using sufficient care. Absorber materials shall be capable of
handling 100mW/cm2 continuously over an eight hour test cycle without damage. A RF
conversion
table
is
available
at
the
following
link:
http://www.compeng.com.au/emc_conversion_tables_field_strength_calculator.aspx. As well all
absorber materials shall have fire retardant additives that reduces the flammability and which
have been tested, and certified by UL.
The second part of this contract involves the refurbishment of the large shielded compact
chamber, also located in 2F. The successful contractor will be required to remove the existing
absorber panels, shielded panels, vents, light fixtures, on the ceiling and to install, test and
warrantee the new microwave absorber panel and shielded panels and the performance as outline
in the specifications. The existing absorber panels and shielded panels, all mounting components
shall be disposed of using standard disposal methods as required by local, provincial and national
regulations. The new absorber panels shall be optimized to provide minimum peak to peak
amplitude ripple within the antenna test volume. Absorber panels shall have reflectivity
performance as shown in Table 4. Absorber materials shall be capable of handling 100mW/cm2
continuously over an eight hour test cycle without damage. A RF conversion table is available at
the
following
link:
http://www.compeng.com.au/emc_conversion_tables_field_strength_calculator.aspx. As well all
absorber materials shall have fire retardant additives that reduce the flammability and which
have been tested, and certified by UL.
3. Specifications
NF Chamber
The physical details of the existing NF chamber (Figure 1) are shown in Table 1. An electronic
CAD file of the existing chamber will be provided in eDrawing format with full measurement
capability. This file can be converted into a STEP file format as required.
The minimum mandatory absorber requirements are listed in Table 2. The absorber length,
configuration and layout shall be selected to provide a -60dB or better reflectivity level in the
quiet zone of the chamber. The quiet zone shall be spherical volume with a diameter equal to a
60 cm minimum.
Walk on blocks shall be provided to gain access to the test positioners and to the probe tower.
The height of blocks shall match with the proposed absorber lengths.
All absorbers panels on the chamber floor shall have a durable, maintenance free. All absorber
panels fitted around the positioners shall be fully painted at the factory. All absorber panels fitted
along the door edge shall be cut at an appropriate angle to facilitate easy opening of the door
without damaging the absorber tips. Aluminum cross braces shall be covered with absorber
panels suitable to reduce their impact on the reflectivity level in the quiet zone. CCT cameras
shall remain in the chamber unless they impact the reflectivity levels.
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The SNF chamber absorber retrofit shall be warranted for a period not less than two years from
the date of completion. This warranty shall include all aspects of the design, fabrication of
absorber and associated installation materials, delivery charges to and from CRC Ottawa, labour
to correct deficiencies, and recertification testing.
Due to the value of the NF chamber, near-field scanner, probe tower, the contractor shall take all
necessary steps to protect the all equipment in the chamber from all damage and the contractor
shall carry liability insurance. The Scientific Authority shall be responsible for arbitrating any
and all disputes. Chamber flooring shall be protected with a minimum 0.5" plywood sheets in
areas where lifting equipment, or scaffolding are being used. All lifting equipment, scaffolding,
shall be certified by CSA and approved for use in the chamber by the Scientific Authority.
Contractor shall ensure all workers conform to all current health and safety regulations, laws, as
applicable.
Figure 1: The SNF chamber
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Table 1: NF Chamber dimensions
Parameter
Value
Overall Chamber Dimensions
144” L x 168” W x 146” H
Primary Door 1, front wall
24” W x 146” H
Secondary Door 2, front wall
71” W x 146” H
Door 3, rear wall
72” W x 146” H
Left wall
144” W x 146” H
Right wall
144” W x 146” H
Rear wall, fixed
96” W x 146” H
Front wall, fixed
72” W x 146” H
Floor
144” L x 168” W
Ceiling
No absorber required
Surfaces
Aluminum
Wall Cross braces, each corner
48” L x 2” W
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Table 2: Absorber Characteristics
Parameter
Value
Absorber configuration
Pyramidal, wedge, twisted, hybrid
Composition
Carbon loaded, polyurethane foam
Min. Reflectivity level, 1GHz,
normal incident angle
-40 dB
Operational frequency range
0.5 GHz to 40 GHz
Maximum reflected signal in quiet
zone, all angles, 1GHz
-60 dB
Minimum continuous power
handling
100mW/cm2
Maximum absorber length
Dependent on quiet zone and L bracket dimensions
Flammability
All absorber material must conform to the following approvals:
NRL Report 8093 (Tests 1, 2, and 3), UL 94-5VA and UL 945VB, UL 94 HBF.
Maximum weight per 24” x 24”
panel
6.2kg
Absorber attachment method
Velcro
Colour
Blue
Operating temperature
-10 to 30 deg. C
Walk on blocks
24” L x 24” W, Height to match absorber length
Special feature #2
Absorber shall be fitted around turntables located on flooring. All
exposed surfaces shall be painted
Special feature #3
Absorber shall be fitted around probe tower. All exposed absorber
surfaces shall be painted.
Special feature #4
Absorber shall be fitted on probe tower as required.
Special feature #5
Absorber sheets shall be used to cover all exposed metal surfaces
within the chamber volume.
Special feature #6
Absorber blocks shall be used in corners of chamber
Special feature #8
All absorber pieces shall bear a serial number on the back of the
absorber that can be easily read.
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Compact chamber
The physical details of the existing Compact chamber (Figure 2) are shown in Table 3
The minimum mandatory absorber requirements are listed in Table 4. The absorber length,
colour, configuration and layout shall match the existing configuration and shall not degrade the
electrical performance of the chamber.
All absorbers on the ceiling shall be secured on to the new shield panel using an approved
contact adhesive and secured with the nylon netting. All new shielded panels, new connector
plates, new fasteners, new vents, new light fixtures, new wiring shall be selected and installed to
provide shielding performance necessary for Mil-STD 461E/F testing and shall be tested as
identified in Table 5. Due to the value of the compact range reflector, feed tower, test
positioners, the contractor shall take all necessary steps to protect the all equipment in the
chamber from all damage and the contractor shall carry liability insurance. The Scientific
Authority shall be responsible for arbitrating any and all disputes. Chamber flooring shall be
protected with a minimum 0.5" plywood sheets in areas where lifting equipment, or scaffolding
are being used. All lifting equipment, scaffolding, shall be certified by CSA and approved for use
in the chamber by the Scientific Authority. Contractor shall ensure all workers conform to all
current health and safety regulations, laws, as applicable.
The compact chamber absorber repair shall be warranted for a period not less than two years
from the date of completion. This warrantee shall include all aspects of the installation,
fabrication of absorber and associated installation materials, shielded panels, vents, light fixtures,
wiring, connector plated, fasteners, adhesives, delivery charges to and from CRC Ottawa, labour
to correct deficiencies, and recertification testing.
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Figure 2: The Compact chamber
Table 3: Compact Chamber dimensions
Parameter
Value
Overall Chamber Dimensions
30 FT L x 20 FT W x 20 FT H
Primary Door 1, front wall
60” W x 72” H
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Table 4: Absorber Characteristics
Parameter
Value
Absorber configuration
Pyramidal, wedge, twisted, hybrid
Composition
Carbon loaded, polyurethane foam
Min. Reflectivity level, 1GHz,
normal incident angle
-35 dB
Operational frequency range
1 GHz to 40 GHz
Minimum continuous power
handling
100mW/cm2
Minimum absorber length
12 inch
Flammability
All absorber material must conform to the following approvals:
NRL Report 8093 (Tests 1, 2, and 3), UL 94-5VA and UL 945VB, UL 94 HBF
Maximum weight per 24” x 24”
panel
5kg
Absorber attachment method
Contact adhesive
Colour
Blue
Operating temperature
-10 to 30 deg. C
Table 5: Compact Chamber Test Requirements
Parameter
Value
MIL-STD 461E/F
Testing shall verify the chamber performance
required to fully meet MIL-STD 461E/F testing
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4. Workflow NF Chamber
The work shall include the following tasks according to the specifications given in Section 3:
 Safe removal and disposal of existing absorber;
 Design the absorber installation for the NF chamber whose characteristics were
specified in Section 3. The design of the new absorber installation shall be optimized
to provide minimum peak to peak amplitude ripple within the antenna test volume.
This requires that the reflected E field be a minimum of -60dB below the desired
transmit signal at 1 GHz;
 Deliver and install the absorbers as outlined in Table 2;
 Test performance of the chamber with the new absorber installation.
5. Deliverable NF Chamber
The retrofit of the NF chamber shall be completed before 27 February 2015. The following items
shall be delivered according to their milestones:
a. Delivery of the absorbers shall be completed by 19 December 2014;
b. Proof of performance test plan shall be submitted to CRC for approval by 19 December
2014;
c. Absorber installation shall be completed by 23 January 2015;
d. Proof of performance shall be completed by 6 February 2015;
e. A detailed final report shall be completed by 20 February 2015, including test setup, test
equipment calibration dates, measurement results, and error analysis. The report shall be
written, reviewed, and endorsed by a registered professional engineer, licensed and
trained for this type of activity.
To summarize, the documents listed in Table 6 shall be provided.
Table 6: Deliverable documents for NF absorber
No
Documents
1
Absorber specifications
2
Absorber layout for chamber showing exact placement of absorber and serial numbers for
each piece of absorber
3
Absorber installation tolerances. There shall be no exposed gaps
4
Installation schedule with milestones
5
Engineering calculations showing expected reflectivity level in quiet zone
6
Proof of performance test plan
7
Final test report
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6. Workflow Compact Chamber
The work shall include the following tasks according to the specifications given in Section 3:
 Safe removal and disposal of existing absorbers and shielded panels, light fixtures,
wiring, fasteners;
 Fabrication of absorber panels and shielded panels;
 Delivery and installation of absorber panels and shielded panels, light fixtures,
conduits, wiring, clamps, new fasteners as required to meet the requirements in Table
4 and 5;
 Test performance of the chamber with the new absorber panels and shielded panels
installed.
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7. Deliverable Compact Chamber
The repair of the compact chamber shall be completed before 27 February 2015. The following
items shall be delivered according to their milestones:
f. Delivery of the absorbers shall be completed by 19 December 2014;
g. Proof of performance test plan shall be submitted to CRC for approval by 19 December
2014;
h. Absorber installation shall be completed by 27 January 2015;
i. Proof of performance shall be completed by 6 February 2015;
j. A detailed final report shall be completed by 20 February 2015, including test setup, test
equipment calibration dates, measurement results, and error analysis. The report shall be
written, reviewed, and endorsed by a registered professional engineer, licensed and
trained for this type of activity.
To summarize, the documents listed in Table 7 shall be provided.
Table 7: Deliverable documents for compact chamber refurblishment
No
Documents
1
Absorber specifications
2
Absorber layout for chamber showing exact placement of absorber and shield panels
3
Absorber installation tolerances. There shall be no exposed gaps
4
Installation schedule with milestones
5
Proof of performance test plan
6
Final test report
8. Language


The Contractor shall communicate in one of the official languages of Canada.
The final report shall be written in English language.
9. Security
As the NF and compact chamber are located on a secure site, all visitors must be cleared by our
site security staff. All contractors holding a valid Canadian citizenship shall submit ID
information 7 working days prior to entering campus. All foreign citizens shall submit a visit
clearance request (VCR) to their embassy 36 to 45 working days prior to entering campus. Please
remember Canadian holidays. All contractors shall adhere to site security protocols, regulations,
and rules.
Contractors may access the site during normal Canadian business hours. No access will be
granted during silent hours or after 6PM.
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Contractors shall park their vehicles in the assign visitor parking area.
10. Scientific Authority
The Scientific Authority (SA) for this contract is David Lee from the Communications Research
Centre – Ottawa, Ottawa, ON, K2H 8S2.
11. Project Schedule
This work will start upon contract award and is to be completed by March 31st, 2015. Milestones
are indicated in Section 5 and 7.
12. Worksite
Contractors shall clean the work area daily and remove all waste material, debris before leaving
the worksite at the end of each work day.
Safety equipment shall be used as required by local, provincial, and nation regulations.
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