Fundamentals of Coaxial Cables

The coaxial line is a shielded and non-dispersive structure, and the main mode of the guided wave in the coaxial line is the TEM wave, but it can also transmit the TE mode and the TM mode. The cutoff frequency is zero, and the corresponding cutoff wavelength tends to infinity. . It is a two-conductor transmission line composed of two coaxial inner and outer conductors and a dielectric in the middle. Generally, the outer conductor of the coaxial line is grounded, and the electromagnetic field is limited between the inner and outer conductors, so the coaxial line has basically no radiation loss and is almost immune to external signal interference. Its operating frequency band is wider than that of two-wire transmission lines, and can be used in bands larger than centimeter waves.