Rigid coaxial cable
Rigid coaxial cables are a group of coaxial cables , which by a rigid ( English rigid metallic tubes are in) outer conductor or inner conductor in the form. The German term "Festmantel-Koaxialkabel" is rarely used. The advantage of rigid coaxial cables is that the leakage radiation and the attenuation , especially at higher frequencies in the GHz range, are lower than with conventional coaxial cables. As a result, greater powers can be transmitted and higher shielding attenuation can be achieved. The disadvantage is the complex processing due to the rigidity, and the area of application is limited to applications where no mechanical mobility of the coaxial cable is necessary.
species
Semi-Rigid Coaxial Cable
Semi-rigid coaxial cables are mainly used in the frequency range from a few GHz to a few 10 GHz. The shape of the cable can be determined by bending it on appropriate bending gauges as part of the cable assembly, after which a change in shape is generally no longer possible. As a rule, the cable is designed without external insulation.
Typical diameters are in the range from 1.5 to 5 mm. The dielectric is practically always made of Teflon . The outer conductor can, for example, be soldered directly to the corresponding SMA connectors , as shown in the adjacent figure. In the case of thicker cables, the inner conductor also takes on the role of a plug pin in SMA connectors. The surface of the cable can be tinned, even with aluminum outer conductors.
Use in high-frequency technology, for example, for transmitters with transmitting powers of up to a few 100 W.
An example of a semi-rigid coaxial cable is the RG402 / U with the following data:
| parameter | value |
|---|---|
| Impedance | 50 Ω |
| outer diameter | 3.6 mm |
| Inner conductor | Wire, 19 AWG |
Rigid-Line coaxial cable
Rigid-Line coaxial cables consist of fixed, unchangeable elements such as straight pieces of cable, angle elements, clamping elements and plugs. In contrast to the semi-rigid coaxial cables, they cannot be bent into shape; both the inner conductor and the outer conductor each consist of a metal tube. The area in between is no longer completely filled with the dielectric like Teflon - instead, spacers in the form of Teflon disks are used at fixed intervals, the remaining area of the dielectric consists of air.
Rigid-Line coaxial cables are designed for the transmission of high HF powers up to the range over 100 kW and are therefore preferably used in the area of the output stages of radio transmitters , for example .
Rigid-Line coaxial cables are used with the following usual dimensions:
| Outer conductor | Inner conductor | |||
|---|---|---|---|---|
| size | outer diameter | Inside diameter | outer diameter | Inside diameter |
| 7/8 " | 22.2 mm | 20 mm | 8.7 mm | 7.4 mm |
| 1 5/8 " | 41.3 mm | 38.8 mm | 16.9 mm | 15.0 mm |
| 3 1/8 " | 79.4 mm | 76.9 mm | 33.4 mm | 42.6 mm |
| 4 1/2 " | 106 mm | 103 mm | 44.8 mm | 42.8 mm |
| 6 1/8 " | 155.6 mm | 151.9 mm | 66.0 mm | 64.0 mm |
Web links
- Rigid-Line coaxial cable , technical information, requested on June 17, 2011, engl.