1. Definition
A semirigid coaxial cable is a type of coaxial cable with a fixed internal structure and a relatively rigid shape, though it can be slightly bent. It consists of a central conductor, an insulating layer, and an outer conductor, usually made of metal tubing (such as copper or aluminum) and shaped cylindrically. Compared with flexible coaxial cables, semirigid coaxial cables have less flexibility but provide more stable electrical performance.
2. Materials
The main materials of semirigid coaxial cables include:
1. Inner Conductor
Usually made of copper (solid copper or silverplated copper) to ensure low resistance and good conductivity.
Can be solid or silverplated solid to improve corrosion resistance and highfrequency performance.
2. Dielectric Insulator
Commonly made of polytetrafluoroethylene (PTFE/Teflon) or foamed PTFE, providing low dielectric loss and high insulation strength.
The thickness of the insulator determines the characteristic impedance, typically 50Ω or 75Ω.
3. Outer Conductor
Usually copper tubing, aluminum tubing, or copperclad steel tubing, giving the semirigid structure.
Surface may be tin or silverplated to improve corrosion resistance and solderability.
4. Outer Jacket (Optional)
Some semirigid coaxial cables include a PTFE or polyethylene jacket for extra mechanical protection and abrasion resistance.
3. Features
Stable Electrical Performance: Fixed internal structure ensures consistent characteristic impedance and signal transmission.
Low Loss: Minimal signal loss at high frequencies, suitable for microwave and RF applications.
SemiRigid: Slightly bendable while maintaining preset shapes, convenient for tightspace routing.
High Temperature and Chemical Resistance: Materials ensure reliable operation in harsh environments.
Customizable: Can be precisely bent and cut to achieve specific shapes.
4. Applications
Semirigid coaxial cables are widely used in highfrequency and highprecision applications, including:
1. RF and Microwave Circuits
Antenna feeds, waveguide connections, internal interconnects in RF modules.
2. Satellite Communication and Radar Systems
Lowloss, highly stable signal transmission for highfrequency signals.
3. Aerospace and Military Equipment
Aircraft, missiles, radar, and electronic warfare devices.
4. Precision Test Instruments
Highfrequency connections in signal generators, oscilloscopes, vector network analyzers.
5. Medical Equipment
Stable RF signal transmission in imaging and RF therapy devices.
