LADDER LINE Meaning and
Definition
-
Ladder line, also known as open-wire line, refers to a type of transmission line used in radio frequency (RF) systems. It consists of parallel conductors, usually made of wire or flat metal strips, separated by insulating material to maintain a consistent separation. The term "ladder line" derives from the pattern created by the parallel conductors, resembling the rungs of a ladder.
This type of transmission line is commonly utilized in antenna systems for its low-loss characteristics. By evenly spacing the conductors and utilizing an insulating medium, ladder line minimizes the energy lost in the form of heat and radiation, resulting in a more efficient signal transfer.
Ladder line is particularly useful in balanced antenna systems, where it serves as the feedline for transmitting and receiving signals between the antenna and the transmitter or receiver. Due to its balanced design, ladder line helps reduce and eliminate common mode currents and minimize radio frequency interference (RFI). This makes it beneficial for applications in amateur radios, shortwave radios, and other RF equipment where interference rejection and signal integrity are paramount.
It is worth noting that ladder line is different from coaxial cable, which consists of a single center conductor surrounded by insulation and a metallic outer conductor or shield. While coaxial cable has its advantages, such as improved shielding from external interference, ladder line is often preferred in specific applications that demand optimal signal transmission and interference rejection.
Etymology of LADDER LINE
The word "ladder line" is a combination of two components: "ladder" and "line".
The term "ladder" originally comes from the Old English word "hlæder", which referred to a device or structure with rungs or steps. The word was derived from the Proto-Germanic word "hlaidri", meaning "rung" or "ladder".
In the context of electrical circuits and radio frequency transmission, "line" generally refers to a conductor or transmission line used to carry signals. The word "line" itself has roots in Old English and Old French, ultimately originating from the Latin word "linea", meaning "linen thread" or "string".
Therefore, when combined, "ladder line" describes a specific type of transmission line consisting of two parallel conductors connected by rungs, resembling the structure of a ladder.
