RG-59

Abstract: A catheter shaft carries a coaxial cable, the terminal end of which contains a dipole antenna with opposing first and second helical elements. The first and second helical elements originate from a common connection to an outer conductor of the coaxial cable. The first and second helical elements are formed by winding flat wire around an outer insulator of the coaxial cable near a terminal end of the coaxial cable. A variable, controllable impedance is connected between an inner conductor of the coaxial cable and a point on the second helical element where the resistive component of the antenna's impedance matches the characteristic impedance of the coaxial cable. The impedance match minimizes reflective losses of the antenna, thereby maximizing power transferred to the antenna. The antenna has an effective electrical length which is equal to one-half the wavelength of the radiation emitted, independent of the physical length of the antenna. The antenna also has a radiation length which can be adjusted by varying the number in pitch and turns of the flat wire and the location of the impedance matching point.

Abstract: A coupling system for transferring a RF signal to and from a high-voltage cable (302) of a power distribution system is described. In one embodiment the coupling system uses a lightning arrester (314) as an element for coupling a RF signal from a RF modem (420) to and from the high-voltage cable. An impedance element of the coupling system is a section of a grounding cable (309) modified with one or more ferrite cores (430) as a means for adjusting the value of the impedance.

Abstract: In an information terminal, a coaxial cable connected a radio-circuit-board, which is often placed at a front section of a case, to an external antenna terminal or an antenna placed at a rear section of the case The terminal having a simple structure prevents a clock signal from leaking to the coaxial cable from a CPU, so that an S/N ratio in receiving can be improved A cable-groove recessed from a bottom to inside is provided The coaxial cable between the radio circuit board and the external antenna terminal or the antenna runs through the cable groove, which is covered with a lid Thus, a clock signal of the CPU can be shielded by the conductive case

Abstract: An earphone antenna includes an earphone cable having first signal lines; a shielded cable including a coaxial cable, a second signal line for audio signals and a grounding wire, the coaxial cable having a central conductor passing high frequency signals surrounded by an insulator and further surrounded by a first shield wire, the coaxial cable, the second signal line, and the grounding wire collectively being surrounded by a second shield wire; a multipin connector arranged on one end of the shielded cable an adapted to electrically connect the shielded cable to a radio apparatus; and a connection block interconnecting the other end of the shielded cable and the earphone cable. The connection block includes a balun for carrying out impedance and balanced/unbalanced mode transformation, and an audio signal transmission path formed by connecting the second signal line and the grounding wire, respectively, to the pair of first signal lines via a high frequency choke exhibiting low impedance for audio signals and high impedance for high frequency signals. By connecting the central conductor of the coaxial cable and the first shield wire to an unbalanced part of the balun, connecting the pair of first signal lines to one end of a balanced part of the balun via a capacitor exhibiting high impedance for audio signals and low impedance for high frequency signals, and connecting the other end of the balanced part of the balun to the second shield wire, a dipole antenna is formed by the earphone cable and the second shield wire.