With the increasing demand for high-speed transmission and high-density wiring such as big data, data centers, AI artificial intelligence and computing centers, 5G, etc., the application of MTP cable has been doubling in recent years. The quality of MPO fiber jumpers determines the stability and sustainability of the entire data center network. Therefore, how to choose good quality MTP patch cable is crucial.
What are the main characteristics of good quality MPO MTP patch cable, and how should they be measured? Below we will introduce to you the selection guide for MTP patch cable.
1. Insertion Loss
Definition: Insertion loss is the power loss when the optical signal passes through the patch cord, unit in dB.
Standard: The insertion loss of high-quality MTP patch cable should be≤0.5dB (multi-mode) or ≤0.7dB (single-mode), the lower the better. For single-mode and multi-mode MTP MPO fiber patch cable with low insertion loss (high quality), the insertion loss is generally required to be < 0.35 dB. It can be shipped only 100% qualified by insertion loss and return loss tester.
Influencing factors: fiber core alignment accuracy, end surface polishing quality, connector tolerance, etc.
When we select MPO MTP cable, we can choose suppliers that provide insertion loss test reports.
2. Return Loss
Definition: Return loss is the loss of optical signals reflected back to the light source, reflecting the end surface reflection performance.
Standard: Single-mode fiber patch cords usually require ≥50dB (APC end face) or ≥30dB (UPC end face), the higher the better. It can be shipped only 100% qualified after test.
Impact: High return loss reduces the interference of signal reflections on the light source.
3. Core alignment accuracy
- Criticality: MPO cable assembly contain multiple fiber cores (such as 12-core, 24-core), and it is necessary to ensure that all fiber cores are accurately connected.
- Standard: Use high-precision guide pins (PIN) and molds to avoid deviation (preferably within ±1μm). Yingda uses SENKO and USCONEC original guide pins, or domestic FSG or three-circle high-quality guide pins to ensure that all products are of the highest quality.
- Impact: Poor alignment can lead to increased insertion loss or signal crosstalk.
4. End surface quality and polishing process
End face type:
- UPC (blue): Curved polish, lower return loss.
- APC (green): polished at an angle of 8°, with higher return loss and suitable for high-speed networks.
Inspection items: The end surface must be free of scratches, dents, and contamination.
In order to ensure that fiber optic connectors have qualified or higher performance, the International Electrotechnical Commission (IEC) developed the IEC 61300-3-35 standard to define whether the connector end face is qualified.
The end face of the MTP MTP cable connector is divided into four areas: core area, cladding area, rubber edge area and ferrule surface. It has requirements for scratches and imperfections in every area inside the joint. Scratches represent permanent linear surface features. Imperfections include all detectable nonlinear features on the fiber, including particles, other debris, pits, chips, edge chips, etc. The cleaner the end face, the better the signal quality the jumper will transmit.
After all MTP connectors have undergone 4 passes of high-precision grinding, each fiber will be inspected one by one with the most advanced end-face detector to ensure that all products are Class A fiber end-faces.
5. Connector material and durability
Shell material: High-quality MPO connectors are made of metal or high-strength engineering plastics (such as PPS), which are resistant to plugging and deformation.
Number of plugs and pulls: Industrial grade jumpers can support ≥500 plugs and pulls (some can reach more than 1,000 times).
6. Fiber type and bandwidth
Multimode fiber (OM3/OM4/OM5): supports short-distance high-speed transmission (such as 40/100G/400G/800G) and needs to match the laser-optimized bandwidth.
Single-mode fiber (OS2): suitable for long-distance, high-bandwidth scenarios with lower loss.
7. Crosstalk
Definition: Crosstalk is the signal interference from adjacent cores in multi-core fiber.
Optimization measures: Use ribbon fibers to be tightly arranged and designed to resist bending, or use low crosstalk MPO fiber (such as MTP® brand fiber).
8. Environmental adaptability
Temperature range: Industrial grade MPO fiber patch cable should support -40℃~+85℃ operating temperature.
Tensile strength: The sheath needs to withstand a certain tensile force (such as ≥100N) to avoid construction damage.
9. Optical cable jacket / sheath material
Sheath material: flame retardant LSZH) , flexible PVC or OFNR. If there are higher requirements for the installation environment, such as suspended ceilings and raised floors, it is best to choose MTP fiber optic cable with higher flame retardant levels, which will not easily burn or smoke in the event of a fire.
When purchasing MTP MPO optical cable, you can check the flame retardant rating directly on the sheath, and then choose the appropriate MPO MTP trunk cable based on the actual applicable environment of the fiber jumper’s sheath and flame retardant grade.
Bending radius: The minimum bending radius (such as ≥30mm) must be met to avoid macro-bending loss.
10. Branding and Certification
Certification standards: Passed TIA/EIA-604, IEC 61754-7 and other international certifications.
Brand reliability: All Yingda’s MPO connectors are from well-known brands such as US Conec, Senko, and Corning. Domestic MPO connectors are from FSG and Three-circle. Optical fiber and cables are from well-known international and domestic manufacturers, with superior workmanship and quality assurance.
How to check the quality of MTP fiber termination?
During MTP’s mass production process, all products go through dozens of production processes and are strictly implemented in accordance with ISO standards. Shipment can only be made after 100% qualification, and the main tests include the following aspects:
- OTDR test: analyze the entire loss and reflection events.
- Insertion loss tester: accurately measure insertion loss and return loss.
- End face detector: Check the end face cleanliness and scratches.
- Polarity test: Make sure the Tx/Rx channel is correct (such as Type A/B/C polarity).
Conclusion
The core of high-quality MTP patch cable are low loss, high alignment accuracy, and strong durability. It is necessary to choose a matching model according to the application scenario (data center, 5G, high-definition video, etc.). When purchasing, it is recommended to give priority to certified brand products and undergo strict acceptance testing.
