80GRC020MSLSTE QUESTIONS AND CLARIFICATIONS.pdf

80GRC020MSLSTE

RFP QUESTIONS & ANSWERS

Page 3 – Section 1.1 – NASA Statement - The second chamber, referred to as the Compact Range, has an interior clear space of 32'-5"L x 13'-2"W x 12'-0"H.

Q1. The 32'-5" length information conflicts with the drawings provided and information provided during the Industry day. The 16FT distance requirement for the direct FF requires the chamber length to be maximum space available of 44’6”. What is the length of the compact range interior clear space?

A1.The clear inside dimensions of the CATR (Room 134) are 44’-9”L x 13’-2”W x 13’-0”H before application of anechoic absorbers. The Statement of Work is hereby amended accordingly.

Page 20 – CATR Measurement Requirements – NASA Statement - The CATR shall be capable of measuring antennas and radar cross section (RCS) per requirements in Table 2 over an operational frequency range of 1 GHz to 110 GHz. The far-field antenna pattern shall have a dynamic range ≥ 90 dB.

Q2. Is the RCS capability required over 1 to 110GHz, or is it limited to Ka band as discussed during the Industry day?

A2. RCS measurements shall operate in the compact range configuration and related frequency range of the CATR as described in the Statement of Work.

HNF Measurement Requirements

Q3. What AUT gain (or size) should be assumed for the FF dynamic range ≥ 90 dB requirement?

A3. FF dynamic range requirement should be met for AUT sizes within the range of ~1-m up to 10-m.

Q4. Is there a requirement to issue array beam steering commands, or just triggering/handshake to update array state? If issuing commands is a requirement, what command format is required and what is the I/O interface?

A4. Triggering/Handshake protocols is acceptable. However, at a minimum, measured data files shall then include marker information to separate pattern measurements in post processing.

Q5. What is the maximum number of array states expected during a single data scan acquisition?

A5. Assume nominal support of 100 array states during a single scan.

Q6. What is the maximum array amplitude taper and/or T/R module attenuation range? Is this needed to determine the required nearfield measurement DR (in addition to the supplied element amplitude and phase accuracies)?

A6. We anticipate up to 32 dB amplitude taper and attenuation range.

Q7. Is 10 m the maximum antenna size that should be assumed for requirement (2) above for entire operating frequency range?

A7. Yes

Q8. Clarification requested. This is CW peak power into the AUT port required for AUT transmit operation?

A8. Yes

Q9. Clarification requested. It is acceptable to support simultaneous dual polarization measurements (in addition to multi-port AUT measurements) at both the AUT and probe using either multiple mixers and/or RF switches.

A9. Simultaneous dual polarization measurement requirements shall meet the requirements of the Statement of Work (see Measurement Requirement 7(b)).

Operations/Control Requirements:

Q10. Please clarify automatic position calibration (automatic position correction?) and what axes are to be included in this calibration.

A10. Automatic position calibration refers to real-time dynamic compensation of positioning errors (e.g. from thermal effects) of the probe relative to the AUT using and external [optical] measurement system. All axes that contribute to error shall be corrected in real-time during measurements.

Q11. Please clarify required accuracy for the measurement of the probe-to-AUT separation distance and expected minimum and maximum separation distances.

A11. Probe positioning accuracy (in all three orthogonal dimensions) with respect to the AUT coordinate system shall be within 25 µm rms. Minimum and maximum separation distances shall be dictated by relevant driving requirements (HNF Measurement Requirements 1-4) in Statement of Work, minimum near field measurement requirements, and proposer’s final design.

Q12. Please elaborate on “AUT Systems”. Does this include AUT electrical power supply and/or RF power?

A12. Regarding Operations/Control Requirement (7), power to AUT system refers to RF power.

Q13. What is expected information for “receiver status” using portable control unit?

A13. Expected information shall include receive signal strength and frequency at minimum.

Q14. What is maximum weight for third third-party hardware to be attached to scanner probe?

Would the probe be removed in this scenario?

A14. Maximum weight for third-party hardware shall be up to 10 kg. In this scenario, probe would be removed.

Q15. Is simultaneous axes control required to support “unique” probe and AUT motion control?

A15. Yes, as well as to support real-time automatic position calibration (see A10).

Software Requirements

Q16. Will external triggers be used for: frequency sweep? Frequency change? Beam state change? Pulse measurement synchronization with array?

A16. External triggers will be necessary for interfacing and coordinating with active antennas (e.g. frequency changes, beam state changes, RF power enable).

Q17. Does software need to support other third-party VNAs in addition to what is to be delivered with the system?

A17. Software should be compatible with 3rd party VNAs, but support for specific 3rd party VNAs is not required out of the box.

Q18. Please elaborate on what is required for automatic range calibration.

A18. Automatic range calibration refers to a means to automatically quantify and suppress range multi-path effects in the measurement of antennas. Proposers can refer to techniques such as Mathematical Absorber Reflection Suppression (MARS) for Near/Far Field Ranges and quiet zone field mapping for (quasi-) Far Field Ranges.

Q19. What is the maximum number of frequencies (in addition to array states) required within a single data scan acquisition?

A19. Antenna frequency and array states can each be on the order of 100 states, however it is expected that total number of states per scan will be optimized based on time and data volume requirements.

Deliverables Requirements

Q20. Please clarify minimum of (8) frequencies. Is this (1) frequency for each of the (8) specified frequency band?

A20. Yes, this requirement refers to a minimum of 1 frequency per identified frequency band.

Q21. Will the scanner and AUT positionings systems be located on their own isolation pad (i.e.

separate from the building/chamber structure)?

A21. The HNF and CATR are individually constructed with isolated 10-inch thick concrete floor slabs.

CATR System

Q22. Please clarify minimum of (8) frequencies. Is this (1) frequency for each of the (8) specified frequency band?

A22. Yes, this requirement refers to a minimum of 1 frequency per identified frequency band.

Q23. Is there a requirement to issue array beam steering commands, or just triggering/handshake to update array state? If issuing commands is a requirement, what command format is required and what is the I/O interface?

A23. Triggering/Handshake protocols is acceptable. However, at a minimum, measured data files shall then include marker information to separate pattern measurements in post processing.

Q24. What is the maximum number of array states expected during a single data scan acquisition?

A24. Assume nominal support of 100 array states during a single scan.

Q25. Clarification requested. This is CW peak power into the AUT port required for AUT transmit operation?

A25. Yes.

Q26. Clarification requested. It is acceptable to support simultaneous dual polarization measurements (in addition to multi-port AUT measurements) at both the AUT and probe using either multiple mixers and/or RF switches.

A26. Simultaneous dual polarization measurement requirements shall meet the requirements of the Statement of Work (see Measurement Requirement 7(b)).

Operations/Control Requirements

Q27. What is maximum weight for third third-party hardware to be attached to probe assembly?

Would the probe and/or the AUT be removed in this scenario?

A27. Maximum weight for third-party hardware shall be up to 10 kg. In this scenario, probe would be removed.

Q28. Is simultaneous axes control required to support “unique” probe and AUT motion control?

A28. Yes.

Additional Overarching Requirements

Q29. Is there a maximum RF power handling requirement for the absorber material?

A29. Refer to maximum EIRP requirements in Statement of Work.

Q30. Need clarification on what is required to coordinate measurements between the HNF & CATR systems. Is this synchronized triggering of the measurement systems? Shared RF signals?

Pulsed RF synchronization & control?

A30. It is expected that a means to establish a common time reference between both the HNF and CATR measurement systems will be available for synchronized motion. Furthermore, a means to provide coupled RF output ports should be available to transfer RF signals between both rooms.

Q31. Are there any drawings available or details on DUT? We will need design and details from OATI in order to budget with proper absorber size and quantities.

A31. The Device Under Test (DUT) will be unique for each measurement and will vary in size from ~1-m to up to 10-m in aperture size. As such, no additional drawings or details exist for DUTs.

Q32. Are there specific power requirements for absorber? The scope of work calls out supporting 60 dBW and we want to make sure that high power absorber is applied where necessary.

A32. Proposals shall provide for a peak field intensity at the absorber of ~1.5kW/m2 in the direction of maximum radiation for both the HNF and CATR. The Statement of Work suggests that pulsed measurements may be used if there is concerns with absorber power limitations.