Avoid Pitfalls When Choosing High-Frequency Signal Cables: How to Prevent Signal Interference and Transmission Delay?Demystifying PD Charging Principles and Proprietary Protocols in One Article

Avoid Pitfalls When Choosing High-Frequency Signal Cables: How to Prevent Signal Interference and Transmission Delay?

I. Disassembly of Key Indicators: Shielding Performance and Transmission Rate, the Core Determinants of Signal Quality

• Shielding Performance: High-frequency signal cables need to isolate external electromagnetic interference through a shielding layer. Common shielding structures include “aluminum foil + braided mesh” and “double-layer braided mesh”. Tests show that high-frequency signal cables using “aluminum foil + 90% coverage braided mesh” have an anti-interference capability more than 60% stronger than those with a single-layer aluminum foil shield. In an environment close to a router (with an electromagnetic radiation value of approximately 30dBμV/m), the signal attenuation rate can be controlled within 5%. However, cables with no shielding or low-coverage shielding may have a signal attenuation rate exceeding 20%, resulting in data transmission stuttering.

• Transmission Rate: It needs to match the actual requirements of the equipment, and there are significant differences in the rate of high-frequency signal cables of different specifications. Taking the common HDMI cable as an example, the HDMI 2.1 version of the high-frequency signal cable can achieve a transmission rate of 48Gbps and support 8K/60Hz video output; the HDMI 2.0 version has a rate of 18Gbps and only supports 4K/60Hz. Tests show that when an HDMI 2.0 cable is used to connect an 8K TV to play 8K videos, there will be 3-5 frame drops per second, while the HDMI 2.1 cable can achieve smooth transmission with a delay of ≤1ms.

• Industry Standards: Choose products that comply with international specifications. For instance, high-frequency signal cables of USB 3.2 Gen2x2 need to meet the USB-IF certification, and their transmission rate and anti-interference performance have undergone official testing. Inferior uncertified cables that claim to “support a rate of 10Gbps” may only have an actual tested rate of 3-4Gbps, which cannot meet the equipment’s needs.

II. Scenario-Based Selection: Gaming, Office, Audio-Visual, Cable Adaptation Requires Attention

• Gaming Scenario: Prioritize high-frequency signal cables with low latency and high shielding performance. For example, a DP cable used to connect a game console to a monitor should be of DP 1.4 or higher version, with a transmission rate of ≥32.4Gbps and a shielding layer coverage of ≥95%. Tests indicate that when using a DP cable that meets the requirements to play shooting games, the operation delay is ≤2ms, which is 60% shorter than that of an ordinary DP cable (with a delay of 5-8ms), avoiding operational errors caused by delay. At the same time, high shielding performance can prevent electromagnetic interference from devices such as keyboards and mice, reducing game screen frame skipping.

• Office Scenario: Emphasize stability and compatibility. For example, an HDMI cable used to connect a laptop to a projector should be of HDMI 2.0 or higher version to meet the 4K/30Hz office presentation needs. Tests show that a standard-compliant HDMI cable has a signal interruption frequency of ≤1 time during 8 hours of continuous office projection; while an inferior HDMI cable may have 3-4 signal losses, affecting meeting efficiency. In addition, the USB-C high-frequency signal cables commonly used in office scenarios need to support “full functionality” (data + charging + video transmission) to avoid the inability to read external hard drives due to incomplete cable functions.

• Audio-Visual Scenario: Focus on signal fidelity. For example, audio signal cables (RCA cables, XLR cables) used to connect audio systems should use oxygen-free copper conductors and have a double-layer braided mesh shielding layer. Tests show that audio signal cables with oxygen-free copper conductors have a 30% lower signal loss than those with ordinary copper conductors. When playing lossless music, the restoration degree of high-frequency details is increased by 25%. If inferior audio cables are used, there will be muddy bass and distorted treble, affecting the audio-visual experience.

III. Quality Judgment Skills: From Appearance to Actual Testing, Avoiding Inferior Cable Traps

• Appearance Details: The outer skin of high-quality high-frequency signal cables is made of bend-resistant PVC or TPE material, with a uniform thickness (≥1.5mm) and no cracks after being repeatedly bent by hand 500 times. The plugs adopt gold-plating or nickel-plating technology, with a gold-plating thickness of ≥5μm, ensuring smooth insertion and removal and tight contact without a loose feeling. Tests show that high-frequency signal cables with gold-plated plugs have a plug-in life of ≥1000 times, while plugs with a nickel-plating thickness of less than 3μm will have poor contact after 300 plug-ins.

• Identification Check: Regular products will clearly mark the specification parameters, such as “HDMI 2.1 48Gbps” and “USB 3.2 Gen2x2 10Gbps”, and have brand logos and certification marks (such as HDMI Forum certification, USB-IF certification). Cables with no identification or vague identification are likely to be falsely marked products. Tests found that an unmarked cable claiming to be “HDMI 2.1” actually has a rate of only 20Gbps, which cannot support 8K transmission.

• Actual Testing and Verification: The judgment can be made based on equipment feedback. For example, if a high-frequency signal cable connecting a computer to a monitor has screen flickering or fails to reach the required resolution, it may be due to insufficient cable rate or poor shielding performance. Professional tools (such as cable testers) can also be used. Tests show that the impedance deviation of high-quality high-frequency signal cables is ≤10%, while that of inferior cables may exceed 30%, which is prone to signal reflection and delay.

IV. Interference Avoidance: Usage and Installation Details to Reduce Signal Loss

• Wiring Method: Avoid laying high-frequency signal cables in parallel with high-voltage lines (such as 220V power cables), and the distance between them should be ≥30cm. Tests show that when the distance is 10cm, the signal attenuation rate of the high-frequency signal cable affected by high-voltage interference is 15%; when the distance is more than 30cm, the attenuation rate can be reduced to within 3%. At the same time, avoid excessive bending of the cable (the bending radius should be ≥5 times the diameter of the cable). Excessive bending will damage the shielding layer and conductor, resulting in a 20%-30% decrease in transmission rate.

• Length Selection: Choose the appropriate length according to needs. The longer the transmission distance of the high-frequency signal cable, the greater the signal attenuation. Tests show that a 10-meter-long HDMI 2.1 cable has an attenuation rate of approximately 8% when transmitting 8K signals; a 20-meter-long cable of the same specification has an attenuation rate increased to 18% and needs to be equipped with a signal amplifier to work normally. Therefore, if the distance between devices in a home audio-visual room is 3 meters, a cable with a length of 3-5 meters is sufficient, and there is no need to pursue an overly long specification.

• Interface Protection: Avoid frequent plugging and unplugging during use. When plugging and unplugging, hold the plug instead of the cable itself to prevent the connection between the cable and the plug from breaking. When not in use for a long time, cover the interface with a protective cap to prevent dust from entering and affecting contact. Tests show that for high-frequency signal cables with good interface protection, the incidence of poor contact after 1 year is ≤5%, while that of unprotected cables reaches 25%.