Updated on February 8, 2019 by Emma Unander

Questions and Answers

Earlier Q&A’s sessions: For Antenna Unit, see Tender 1 details, First Stage Receiver Unit, see Tender 2 details and for Sub-Array Transmitter Unit, see Tender 3 details

— 2018-12-20: Start of E3DS1 PSCU questions and answers phase —

Question 161: The budget indicated in the Call for Expression of Interest was 30 MSEK. Is this a maximum value which cannot be overpassed? Does it include item 1 (R&D phase + first article) and item 2 (228PSCU) or also options?
Answer 161: Mentioned 30MSEK is an estimation of the procurement including item 1 and item 2. Is not a maximum value. Options aren’t included int this number.

Question 162: If some of the required documents are already delivered in EOL, do we need to send them again?
Answer 162: We like to receive a full package of required documents. Please add copy of also previously delivered documents in to your tendering files.

Question 163: Document “App4 Requirements answer template for E3DS1 PSCU”: Isn’t a specific Technical Proposal needed besides Table 3.1 Technical Requirements?
Answer 163: Technical Proposal is not required but we highly recommend to include one so that we can verify that proposal is acceptable.

Question 163: Document “App4 Requirements answer template for E3DS1 PSCU” : Delivery Dates says: Second contract phase, procurement Object 1 :  End of 2019 Is this correct?
Answer 163: No, this is wrong. Correct delivery shall be Summer 2020 as it’s in the Call for EOL.

Question 164: As far as I understood, PSCU do not generate the pulse (“Waveform details are calculated external to the PSCUs […] and shall be saved to the memory of the PSCU”, extracted from Technical Specification, p. 8). Where is the pulse shape coming from? What amount of memory is needed to store pulse shapes? 
Answer 164: Correct, vermiformes (pulses) are pre-calculated in the Site cluster and then downloaded in to all PSCUs. Our requirement for the memory is 1 GB but bigger is an advantage. Pulses can all be different length from 0.3 to 3000 us.

Question 165: Testing:

  • What testing is needed (inspection, functional, temperature, vibrations, EMC, radiation…)
  • Is the testing of the First article more thorough than the that of the series?
  • What are the lifetime ambient conditions?
  • Are we supposed to propose a testing plan?

Answer 165: We expect that all devices are tested before delivery. Addition to performance measurements also variations over operational temperature range from 15 to 40 degC ambient air. Also we require EMC tests to be done. First article will be tested with amplifiers in EISCAT site by EISCAT personnel but suppliers are welcome to follow the tests. PSCUs will be installed in to subarray containers which are equipped with climate control devices to keep temperature between 15 and 40 degC. Testing description will be required when project starts.

Question 166: Reliability: what is the desired lifetime of the PSCU? Are maintenance stops planned?
Answer 166: Required lifetime for electronics is 15 years. Radar will not be operated continuously and there will be regular technical stops for upgrading and services. However, sites are unmanned and in remote locations so reliable operation is expected.

Question 167: What is the Phase & Amplitude imbalance between outputs?
Answer 167: Phase balance between any channels with in one PSCU shall be smaller than 5 degree (standard deviation) and between any PSCU units smaller than 10 degree. (Requirement SS_PSCU_20).

Amplitude error has not been mentioned and it shall be added to the Technical Specification. Amplitude error between any channels shall be better than 1 dB.

Question 168: Are there 8 differently phased signals (2 equal signals, one per polarization) or 16 differently phased signals?
Answer 168: There should be 16 differently phased outputs. Polarization is calculated in advance to the phase value.

Question 169: How many I&Q levels are there? What is the rate level?
Answer 169: In the requirement SS_PSCU_11, it’s mentioned that input data stream shall be 52 MSPS and 16 bit for both I and Q. No other rates are required.

Question 170: Is there any preferred architecture for the PSCU (MTCA, PCI,…)?
Answer 170: No preferred architecture.

Question 171: SS_PSCU_06 states that UDP will be used for the command stream but there are only high level descriptions (SS_PSCU_07 & SS_PSCU_09) of what type of information the event stream data will contain. Is there a more detailed description of the event stream protocol available? Or is it up to us to define the protocol? In the latter case there is need for more detailed system level descriptions regarding the communications within the system.
Answer 171: It’s up to supplier to design the protocol but EISCAT likes to be involved closely in this process. Each PSCU is connected to the Site computer cluster through WR compatible 1GbE network as it’s mentioned in the Technical Specification. Cluster software will be developed same time as radar hardware and can adapt to different protocols. Protocol design has to start from PSCU as that is the most critical to ensure the required communication speed.

Question 172: Is there a definition for the spectrum mask?
Answer 172: The spectrum mask is calculated to the waveform already in the Site Computer before downloaded to the PSCUs.

Question 173: Should filtering be done in the PSCU or is that handled in the power transmitter unit?
Answer 173: PSCU shall not do any filtering. Spectrum masking is done in waveform and harmonics rejection in SSPA unit.

Question 174: SS_PSCU_20 and SS_PSCU_21 states that phase errors should be within “[X] degrees standard deviation”. Does this imply that the phase errors between channels and units can be ±X degrees in 6 8,2% of measures? Otherwise can you please clarify the requirement?
Answer 174: Yes, this is correct. Better sentence is ‘phase variation between channels’ which will be changed to the next Technical Specification.

Question 175: We would normally not recommend BNC connectors for this type of design where frequent unit replacement does not seem to be a requirement. Is BNC connectors a hard requirement or can we suggest a more suitable connector?
Answer 175: Other end of the cable at the SSPA is already decided to be BNC, so naturally also PSCU should be. Installation time of many hundreds unit shall taken in to account and then BNC is more suitable than SMA. But we are open to all suggestions.

Question 176: Will EISCAT have some system simulation resources that we can access instead of designing/procuring our own? For example generating command streams, timing information, etc.
Answer 176: EISCAT is willing to develop some simulators and work together for testing but main responsibility shall be suppliers.

Question 177: Can you provide a system description regarding cooling? Preferred flow directions, air volumes, pressure levels, fans in rack or in the units etc.
Answer 177: Because High Power Amplifiers in the same rack, there will be enough cooling power for PSCU. Fans in the unit and airflow front to back is preferred but we are open for other solutions. We will add description of the environment to the next version of the Technical Specification.

Question 178: What is the requirement in the stability of the amplitude?
Answer 178: 1 dB between any output at any time.

Question 179: What is the maximum delay respect to the non-delayed waveform? Are all the delay multiple of a minimum delay?
Answer 179: This is misunderstanding of the concept. There is no delay, only UTC (or TAI) time to start process and carrier phase adjustment.

Question 180: Is there any need for spares?
Answer 180: Yes, details will be negotiated during the contract negotiation phase.

Question 181: Wanted to know if EISCAT can attribute the extra 432 and 660 to a contractor different from item 1 (R&D + first article) and item 2 (228 units), and also if EISCAT can transfer the design of item 1 and item 2 to this new contractor. In other terms, whose is the industrial property of the design?
Answer 182: No, contract with options will be made with one signale contractor. EISCAT does not have any requirements for industrial property of the design. However, property rights shall be clearly mentioned in the offer.

Question 183: What is expected phase resolution in the command (SS_PSCU_17).
Answer 183: No exact requirement but it shall be better than 5 deg. For example 8 bit value over 360 deg would be perfect.

Question 184: Should the RF-connectors be placed on the front or rear of the unit?
Answer 184: We would prefer front panel for connectors.

Question 185: What is the baseband signal bandwidth; and can other sampling rates than 52MSPS that is adequate for this bandwidth be selected?
Answer 185: Actual baseband signal is 6 MHz wide but for other reasons like nonlinearity correction and spectral shaping we like to have 52 MSPS. It is also same as we used for receiver and may give some advantages for analyzing.

Question 186: Shall a transceiver be fitted in the control interface SFP slot, or do your provide this? If the former is true; which variety of 1Gb ethernet
shall be selected?

Answer 186: We will provide the White Rabbit compatible SFP transceivers. Correct model will be chosen during the development phase.

— 2019-01-31: End of E3DS1 PSCU tendering specifications dialoque period —

Page updated: 2019-02-04 (Q&A no 186)

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