Ultra-Wideband Miniaturized Omnidirectional Antennas Via Multi-Mode Three-Dimensional (3-D) Traveling-Wave (TW)

An ultra-wideband dual-band dual-feed cable comprising:

• an assembly of two concentric cables comprising an inner cable and an outer cable, the inner and outer cables sharing a common concentric cylindrical conductor shell, wherein the common concentric cylindrical conductor shell serves as the inner conductor of the outer cable and simultaneously serves as the outer conductor of the inner cable;
• wherein the outer cable covers a frequency band of a lower median frequency and the inner cable covers a frequency band of a higher median frequency;
• wherein each cable has two ends, one end connected to a device, the other end connected to an output terminal for connection to a common output device;
• and
• wherein the inner cable is connected to a first electrical device on one end and to a coaxial output terminal on the other end to convey a high-frequency output to the common output device, and the outer cable is connected to a second electrical device on one end and to the common output device on the other end to convey a low-frequency output to the common output device through a printed circuit board.