As we all know, SYV aluminum foil shielded and copper braided shielded coaxial cable is a broadband transmission line with the characteristics of low loss and high isolation. A coaxial cable consists of two concentric cylindrical conductors separated by a dielectric spacer. Capacitance and inductance distributed along the coaxial line create distributed impedance, or characteristic impedance, throughout the structure.

Coaxial cables have some important frequency-dependent properties that define their application potential - skin depth and cutoff frequency. Skin depth describes what happens to higher frequency signals propagating along a coaxial line. The higher the frequency, the more the electrons tend to move towards the conductor surface of the coaxial line. The skin effect results in increased attenuation and dielectric heating, causing more resistive losses along the coaxial line. To reduce losses due to the skin effect, larger diameter coaxial cables can be used.
Obviously, improving the performance of SYV aluminum foil shielded and copper braided shielded coaxial cable is a more attractive solution, but increasing the size of the coaxial cable will reduce the maximum frequency that the coaxial cable can transmit. The coaxial cable cutoff frequency is created when the wavelength magnitude of the EM energy exceeds the transverse electromagnetic (TEM) mode and begins to "bounce" along the coaxial line as the transverse electrical 11 mode (TE11). This new frequency mode presents some problems. Since the new frequency mode travels at a different speed than the TEM mode, there will be reflections and interference with the TEM mode signal traveling through the coaxial cable.
To solve this problem, the size of SYV aluminum foil shielded and copper braided shielded coaxial cable should be reduced and the cutoff frequency should be increased. There are now coaxial cables and coaxial connectors that can reach millimeter wave frequencies. It is worth noting that reducing the physical size to accommodate higher frequencies increases the loss of the SYV aluminum foil shielded and copper braided shielded coaxial cable and reduces the power handling capability. Another challenge in fabricating these extremely small components is the tight control of mechanical tolerances to reduce significant electrical defects and impedance variations along the line. For cables with relatively high sensitivity, this can be expensive to achieve.