Our coaxial and twinaxial cables are designed to meet specific RF industry specifications, and are available in 84 coax and 2 twinax versions. With Xundiancable, you can choose coaxial cable with impedances of 50 Ohms, 52 Ohms, 53 Ohms, 75 Ohms, 93 Ohms, or 95 Ohms, and twinax cable with impedances of 100 Ohms or 78 Ohms. It is possible to purchase coaxial cables with double shielding, single shielding, or triple shielding. From the deepest, broadest inventory of microwave and RF components available in our ISO 9001:2015 certified manufacturing facility, we ship RF cables in coax and twinax on the same day. In addition to exceptional customer service, our technical support team is available to assist our customers.
What is RF coaxial cable
The three elements of RF coax are an outer conductor, a center conductor, and an insulating spacer between the two conductors. Coaxial cables transmit electrical signals through a center conductor, generally a single solid copper wire.
An insulation layer surrounds the solid copper wire, which is surrounded by a woven metal braid. Cables are often protected by an insulating layer, also known as an outer jacket. Coax eliminates virtually all electrical and magnetic leakage by design. With minimal leakage outside the braid, these fields are restricted to the dielectric.
Structure of coaxial cables
Due to the shielding inside the cable, electric and magnetic fields outside the cable do not interfere with signals inside it. As a result of this characteristic, coax is particularly suitable for transmitting electrical signals that do not tolerate interference from stronger external electrical signals or may cause interference from co-site signals.
Central conductor: silver plated copper wire or tinned copper wire is generally used. The silver plated on the surface ensures long-term high-frequency transmission performance and high temperature resistance.
Medium: generally, soluble polytetrafluoroethylene (PFA), polytetrafluoroethylene propylene (FEP) and high-density polyethylene (HDPE) are used as insulation materials with low dielectric constant, good high-frequency performance, good bending performance and high temperature resistance.
Outer conductor: generally, silver plated copper wire or tinned copper wire is used for weaving, which is characterized by softness, convenient processing and high temperature resistance, and also meets the needs of crimping and welding during connector installation.
Jacket: generally, soluble polytetrafluoroethylene (PFA), polytetrafluoroethylene propylene (FEP) and polyethylene (PE) are used, which are characterized by high temperature resistance, friction resistance, aging resistance, salt fog resistance, good flexibility and bending resistance, especially suitable for installation in narrow and complex spaces.
Applications of coaxial cables
In radio frequency transmission, coaxial cables are primarily used for tight impedance and RFI/EMI control. This is particularly significant when signal loss and interference are detrimental to overall system performance in RF and microwave applications with 50- and 75-ohm impedances. Cable assemblies that are electrically stable are a common requirement in the Military/Aerospace market.
Here is a list of the most critical performance aspects of coaxial assemblies.
Dielectric:
An insulating material between the inner and outer conductors of a coaxial cable that conducts electricity poorly. This category includes materials such as polytetrafluoroethylene (PTFE), ethylenetetrafluoroethylene (ETFE), and fluorethylenepropylene (FEP).
Frequency:
Energy in the form of a wave; measured in Hz (Hertz). Microwave and RF frequencies range from high frequencies (HF) 3-30 MHz, ultra-high frequencies (UHF) 3-3GHz, super high frequencies (SHF) 3-30GHz, to extreme frequencies (EHF) 30-300GHz.
VSWR:
It is a ratio that indicates how efficiently RF is transmitted from a source to a load through a transmission line. As frequency increases, the ratio values increase.
Impedance:
Measurement of resistance to current flow, in Ohms.
Insertion Loss:
It is measured in decibels (dB); as frequency increases, it increases.
Bend Radius:
Minimum radius of a bend that does not impact electrical performance; measured to the inside curve. Dielectric can stretch when coax is bent beyond specifications, forcing the center conductor off center. The conductor-shield relationship changes, resulting in a change in impedance, which results in higher Voltage Standing Wave Ratios (VSWR). With increased insertion loss, impacts can also be seen.
Shielding:
Conducting shield made of foil or braid. Shielding and shielding effectiveness of coax vary. Several factors determine how much shielding is needed: conductor diameter, bend radius, and electrical requirements.