10 Features of Semi-Rigid Cable Assemblies

Semi-rigid cable assemblies are specialized cables designed for high-frequency applications, such as in RF (radio frequency) and microwave communications. They are characterized by a combination of flexibility and mechanical stability, making them suitable for various applications. Here are some key features of semi-rigid cable assemblies:

1. Independent microwave components
Semi-rigid cable is a type of microwave assembly. Therefore, the specifications are as important as that of the coupler, bridges, and amplifiers. These cables can be long-lasting if properly connected to other system components.

2. Broadband coverage
Semi-rigid cable assemblies support data transmissions of up to 65GHz. The cables can support an even higher frequency of 110 GHz if using a cable terminated with 1.0mm connectors.

Semi-rigid coaxial cables are available in various diameter sizes between 0.034 to 0.250 inches. The most popular sizes are 0.141 and 0.086. In addition, the 0.047 has become more popular in support of higher frequencies using more miniature form adapters.

0.141 inches semi-rigid coax transmission ending with high-frequency SMAs or 2.92mm supports a frequency of up to 27Ghz. At the same time, 0.086 inches transmission ending with 1.85mm will support up to a frequency of 65GHz.

3. Shaping and maintaining shape
As the name suggests, these cables are sturdy enough to hold their shape and are flexible enough to bend using hands. So, manufacturers can form these cables into precise shapes to fit into the system’s design. But it’s best to use special tools to avoid damaging the outer pipe wall when bending.

A point to note, once you bend these cables, the shape can’t change again. Ignoring this factor will only affect the electrical functions of the semi-rigid cables. After all, the shape change can damage the outer wall of the cable.

4. Phase stability
Due to changes in temperatures, the properties of materials will change, so it is vital to use phase-stable cables in most critical systems. Materials used to manufacture these cables are of high quality. Therefore, they are electrically stable as compared to flexible coax.

Additionally, systems need phase-length control, especially antenna systems. During manufacturing, the cable lengths are slightly longer to give room for future adjustments. However, with semi-rigid cables, you don’t need that; you can always bend the cable to suit your needs and match it in its final bend configuration.

5. Low passive intermodulation (PIM)
Manufacturers use non-ferrous materials such as copper to make semi-rigid cables. When aligned with proper connectors, the copper tube semi-rigid coax has a perfect PIM performance, which makes it ideal for modern multi-frequency wireless communications systems such as DAS (Distributed Antenna System).

6. Deliver Maximum Power Transfer
Semi-rigid cables deliver maximum power transfer through impedance control. The characteristic impedance is the result of the center and dielectric diameters along with the dielectric constant of the insulator.

7. High isolation 
Semi-rigid cables can have isolation up to 100 dB.

8. Low Loss Performance 
These cables are typically constructed from high-quality dielectric materials, which help reduce signal loss, making them ideal for high-frequency applications.

9. Compact Size
The semi-rigid construction allows for smaller diameter cables, enabling tighter packaging in applications where space is a premium.

10. Environmental Resistance
Many semi-rigid cables feature durable jackets and materials that can resist environmental factors, including temperature extremes, moisture, and chemical exposure.

Applications of Semi-Rigid Coax Cable Assemblies:

• Defense electronics
• Test and measurements instrumentation
• Military and aerospace
• Telecommunications

Semi-rigid cable assemblies are coaxial transmission lines that consist of a metal tube with a metal wire conductor running down the center. The primary function of a cable assembly is to transfer electrical signals or power from one point to another.