Five "knowledge points" about semi-rigid cables(1)

The most basic form of semi-rigid cable assembly is a coaxial transmission line composed of a metal tube. Among them, the metal tube used is generally a copper tube forming an outer conductor, and a metal wire conductor is provided along the center line of the copper tube. The central wire conductor is supported by the dielectric material so that it can be kept on the same central axis as the outer conductor.

The following are the 5 most important points about semi-rigid cables:

1. Independent microwave components

The first thing that needs to be clearly understood is that the semi-rigid cable assembly itself is a type of key microwave assembly, and it is extremely important to realize this. This means that the specifications of semi-rigid cables are as important as the specifications of any couplers, bridges, and even amplifiers. If made properly, the cable can successfully play a predictable and stable effect in connecting other components of the system. As long as you study any good link budget analysis, you can find that at a given frequency, electrical parameters including attenuation and voltage standing wave ratio play a vital role in the transmission and reception of RF signals. . Comparing the semi-rigid cable and the standard RG cable, it can be found that when the space is suitable and the heat cycle and other required tests are carefully checked, when a semi-rigid cable assembly is installed with a soldered connector, every connector is installed. The time required can be as long as an hour or more; in contrast, crimp-type RF connectors for flexible (non-semi-rigid) coaxial cables can be installed in one minute or less.

2. Broadband coverage

Semi-rigid cable assemblies usually support radio frequency signal transmission within 65 GHz. In addition, although not commonly used, cable assemblies terminated with 1.0mm connectors can achieve high frequency applications up to 110 GHz. Semi-rigid coaxial cables vary in size, ranging from 0.020 inches to 0.250 inches in diameter. Among Pasternack's products, 0.141-inch and 0.086-inch cables are the most commonly used models. At the same time, 0.047-inch diameter cables with smaller connectors are becoming more and more popular with users because they can support higher frequencies. The 0.141-inch diameter semi-rigid coaxial cable is terminated with high-frequency SMA or 2.92mm connectors, and the application conditions can usually be as high as 27GHz. Although 0.086 inch diameter semi-rigid coaxial cable is often used with SMA connectors, when it is terminated by a 1.85 mm connector, the operating frequency can reach up to 65 GHz.

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1. Five "knowledge points" about semi-rigid cables(2)

2. Five "knowledge points" about semi-rigid cables(3)