Micro Coaxial Cable factory

How to Properly Document Micro Coaxial Cable Test Results

Documenting micro coaxial cable test results accurately is crucial for quality control, troubleshooting, failure analysis, and ensuring reliable performance in your applications. Proper documentation creates a clear record for anyone reviewing the data now or in the future. Here’s a step-by-step guide focusing on what matters most:

Essential Information to Include:

1. ​Header Information:
   • ​Report Title/ID: Clear identifier (e.g., “Micro Coax Test Report – Batch# XYZ123”)
   • ​Date: Date(s) testing was performed.
   • ​Tester Name/ID: Person(s) who performed the tests.
   • ​Location: Where testing was conducted (if relevant).
   • ​Instrumentation Used: List the key test equipment (e.g., “VNA: Keysight N9918A”, “LCR Meter: Fluke PM6306”, “TDR: Tektronix DSA8300”, “Cable Tester: MultiContact CrimpStar IV”).
2. ​Cable Specification & Identification:
   • ​Manufacturer & Part Number: (e.g., “CompanyX – MCX-042-50-SS”)
   • ​Detailed Cable Spec: Impedance (50Ω or 75Ω), core conductor material/gauge (e.g., “26AWG Silver Plated Cu”), dielectric type (e.g., “Foamed PTFE”), shield construction (e.g., “Dual Shield: Braid + Foil”), outer jacket material (e.g., “PVC”), overall diameter (e.g., “1.13mm”).
   • ​Cable Length Being Tested: Specify precisely (e.g., “1.00 meter”).
   • ​Cable Sample Identifier/Lot/Batch Number: Essential for traceability.
   • ​Connector Types: Specify the connectors on each end precisely (e.g., “End A: U.FL (IPX)”, “End B: MMCX”).
   • ​Connector Termination Quality Notes: Any observations during visual inspection before electrical testing.
3. ​Test Setup Details:
   • ​Test Configuration Sketch/Diagram: (Highly Recommended) Even a simple sketch showing:
     • Test equipment inputs/outputs.
     • Cable under test orientation.
     • How connectors interface to fixtures/test ports (e.g., “End A -> VNA Port 1 via SMA(f)-U.FL(m) adapter”). Include model numbers of key adapters/fixtures.
     • If using a reference plane or calibration type.
   • ​Calibration: Record calibration method used (e.g., “SOLT Calibration performed on VNA Ports 1 & 2 to SMA(f) interface plane prior to test”) and date of last calibration.
   • ​Test Parameters: Specific settings on the instruments:
     • VNA/TDR: Start/Stop Frequency, Number of Points (or Resolution), IF Bandwidth, Averaging Factor, Power Level. Especially for TDR: Pulse Rise Time, Acquisition Time.
     • LCR Meter: Test Frequency (e.g., “1 MHz”), Test Signal Level (e.g., “1V RMS”).
     • Continuity Tester: Applied voltage/current limits (if applicable).
   • ​Environmental Conditions: Temperature and Humidity (if controlled or significantly deviating from standard lab conditions).
   • ​Connector Torque: If torque wrenches are used for mating connectors to test ports, note the applied torque (e.g., “U.FL mating: Finger tight only”, “SMA adapter mating: 8 in-lbs”).
4. ​Measured Test Results:
   • ​Test Specification: Clearly state the specification/standard each test relates to (e.g., “Insertion Loss < 0.8 dB @ 6 GHz per MIL-DTL-17” or “DC Resistance < 0.5 Ohms/m per Manufacturer Spec Sheet”).
   • ​Recorded Values: For each test performed:
     • ​Continuity & Shorts: “Pass” (Open between center/shield, continuity along center, shield continuity established) OR detailed description of any failure.
     • ​DC Resistance: Value measured at each conductor (Center Conductor Ω/m or Ω total; Shield Ω/m or Ω total).
     • ​Capacitance (pF/m or pF total): Measured value.
     • ​Insulation Resistance: Value measured (e.g., “> 1000 MΩ @ 500VDC”) and test voltage/duration.
     • ​Insertion Loss/Attenuation: Results at ​specified frequency points, especially maximum operating frequency and critical intermediate points. (e.g., “0.65 dB @ 1 GHz”, “1.05 dB @ 6 GHz”). Plotting is ideal, but tabulate key points.
     • ​Return Loss / VSWR: Results at ​specified frequency points. (e.g., “Return Loss: 18 dB @ 6 GHz” or “VSWR: 1.25:1 @ 6 GHz”).
     • ​Propagation Delay: Measured value (e.g., “4.85 ns/m”).
     • ​Delay Skew (if applicable): Between conductors in a multi-cable assembly.
     • ​Structural Return Loss (SRL) / Impedance Profile: Key observations from TDR trace (e.g., “Impedance average: 51.2Ω”, “Maximum deviation: ±2.5Ω”, location of any significant anomalies).
   • ​Visual Inspection: Note any visible damage (kinks, cuts, jacket nicks, crushed connectors) observed pre/post-testing.
   • ​Bend Radius Test Results: Document the test radius used (per specification), number of flex cycles, Pass/Fail status with failure criteria, and any performance measurement taken after testing (e.g., “Loss after 1000 bends: +0.15dB @ 6GHz vs pre-bend”).
5. ​Conclusion & Review:
   • ​Pass/Fail Status: Clear statement: “All tests passed specifications” or “Failed: Shield DC Resistance exceeded limit – See Test #DCR-S02”.
   • ​Approvals: Space for signatures/dates of test engineer and reviewer.
   • ​Attachment Reference: If plots or detailed data files are generated, reference them clearly here (e.g., “See attached file: MCX-042-Batch_Plots.pdf”).

Formatting Tips for Clarity:

• ​Use Tables: Organize results logically. Have separate tables for Cable Info, Test Setup, and Result Data.
• ​Be Specific: Instead of “Connector”, write “U.FL (IPX)”. Instead of “Low Loss”, write “Insertion Loss = 0.72 dB @ 6 GHz”.
• ​Plot Graphs: Where trends matter (like Loss/RL vs. Frequency), graphs are essential. Ensure axes are clearly labeled. Save plots as images or PDFs linked to the report.
• ​Notes Section: Add a section for any relevant observations not captured elsewhere (e.g., “Minor shield fraying noted at End A during connector visual – did not affect electrical results”).
• ​Electronic & Physical Copies: Store securely. Ensure digital filenames are descriptive and include date/lot number.

Sample Results Table Snippet:

Common Mistakes to Avoid:

• ​Missing Traceability: No cable part number, lot number, or unique sample ID.
• ​Unclear Test Setup: Not documenting adapters, calibration reference plane, or torque makes replication impossible.
• ​Reporting Only “Pass/Fail”: Losing the actual measured values provides no detail for future analysis or trend spotting.
• ​Vague Results: Reporting “Insertion Loss: Good” instead of specific values at specific frequencies.
• ​Missing Frequency Points: Not reporting loss/RL at the cable’s maximum specified operating frequency.
• ​Ignoring Visuals: Failing to document pre-existing physical damage can lead to incorrect failure attribution later.
• ​Ignoring Test Conditions: Not recording temperature/humidity or specific instrument settings can make data hard to interpret or compare later.
• ​No Summary/Conclusion: Forcing the reader to hunt through all data to determine if the cable passed overall requirements.
• ​Disorganized Presentation: Scatter information, making the report hard to follow.