Analysis of the mystery of RF Test Cable

RF Test Cable is a standing item in the RF and microwave industries. This is because such RF Test Cable connections are required for all critical equipment, from smartphones and laptops used in everyday life to radars and Global Positioning Systems (GPS) in the military and aerospace fields. However, maintaining adequate signal integrity while passing signals from one device to another is a challenging task for nearly every application. Implementing complex dynamic signal paths requires a highly flexible platform that can be used in a variety of environments and applications.

The most basic RF Test Cable structure includes a center conductor, a cylindrical symmetrical conductive shield, and an air-like medium that separates the two. This "cylinder-in-cylinder" conductor structure enables electromagnetic signals below the maximum cut-off frequency to generate transverse electromagnetic waves (or electromagnetic waves with perpendicular magnetic and electrical components) in the separation area between the two conductors.      

For signals beyond the cutoff frequency, non-perpendicular transverse electric and transverse magnetic waveguide modes can also be generated due to their extremely small wavelengths. These two additionally generated waveguide modes can lead to degradation of signal integrity and signal performance. In general, the larger the diameter of the RF Test Cable, the lower the cutoff frequency. In addition, the power that the RF Test Cable can withstand increases with size. Due to the high sensitivity of the above-mentioned transverse electromagnetic waves in the RF Test Cable, all geometric components of the cable must be consistent throughout the transmission line. Otherwise, there will be many problems with signal reflection reduction and phase change. “Engineers must raise the importance of RF Test Cables to the same level as other microwave devices. Engineers often spend tens of thousands of dollars for precision amplifiers, filters, or other devices that make a difference to system performance for design purposes. high impact device”

"When the RF Test Cable is used unreasonably, the system performance will be greatly affected", ZOMWAVE believes that the function of the RF Test Cable is like a PVC pipe, at best, it transfers the signal from one place to another. In fact, choosing or arranging an RF Test Cable without consideration will have a very detrimental effect on performance. This is why performance parameters such as Voltage Standing Wave Ratio (VSWR), Insertion Loss, and Phase Length are all so important, and why customers pursue such parameters when purchasing high-end RF Test Cables.