Abstract: An electromagnetic transmission and reception system comprises a transmitter section and a receiver section. The transmitter section has a first signal source, a second signal source at a lower frequency than the first signal source, and means for generating from the first and second signal sources a plurality of signals with fixed frequency spacing derived from the second signal source frequency. One or more pairs of the plurality of signals are selected, and for the or each pair, the signals of the pair are combined to derive an output signal having a frequency derived from the difference between the frequencies of the signals of the pair. The receiver section combines a received signal, which comprises a received version of the output signal, with a local oscillator signal for frequency down-conversion of the received signal. This local oscillator signal is generated by the transmitter section.

Abstract: A fiber wrap and a method of rotating the fiber wrap without twisting a data cable are disclosed. The fiber wrap includes a sun gear, a sun cylinder coupled to the sun gear, a planetary gear in contact with the sun gear, a planetary cylinder coupled to the planetary gear, an outer housing in contact with the planetary gear, and a data cable coupled to the sun cylinder, the planetary cylinder, and the outer housing. The maximum bend radius of the data cable is determined by the equation: 2 ? ?? ? ? DGD ? c ? wherein ? is optical wavelength and ? ? ? DGD = 0.5 ? C s ? ( r R 2 ) 2 ? ? ? ? L c - 0.5 ? C s ? ( r R 1 ) 2 ? ? ? ? L c wherein Cs is the stress-optics coefficient, c is the speed of light, R1 is the bend radius at the end of the wrap motion, R2 is the bend radius at the start of the wrap motion, r is the radii of the sun cylinder and the planetary cylinder, and ? ? ? L = 10 360 ? 2 ? ? ? ? R 2 .

Abstract: A fiber wrap and a method of rotating the fiber wrap without twisting a data cable are disclosed. The fiber wrap includes a sun gear, a sun cylinder coupled to the sun gear, a planetary gear in contact with the sun gear, a planetary cylinder coupled to the planetary gear, an outer housing in contact with the planetary gear, and a data cable coupled to the sun cylinder, the planetary cylinder, and the outer housing. The maximum bend radius of the data cable is determined by the equation: 2 ? ?? ? ? DGD ? c ? wherein ? is optical wavelength and ? ? ? DGD = 0.5 ? C s ? ( r R 2 ) 2 ? ? ? ? L c - 0.5 ? C s ? ( r R 1 ) 2 ? ? ? ? L c wherein Cs is the stress-optics coefficient, c is the speed of light, R1 is the bend radius at the end of the wrap motion, R2 is the bend radius at the start of the wrap motion, r is the radii of the sun cylinder and the planetary cylinder, and ? ? ? L = 10 360 ? 2 ? ? ? ? R 2 .

Abstract: A fiber wrap and a method of rotating the fiber wrap without twisting a data cable are disclosed. The fiber wrap includes a sun gear, a sun cylinder coupled to the sun gear, a planetary gear in contact with the sun gear, a planetary cylinder coupled to the planetary gear, an outer housing in contact with the planetary gear, and a data cable coupled to the sun cylinder, the planetary cylinder, and the outer housing. The maximum bend radius of the data cable is determined by the equation: 2 ? ?? ? ? D ? ? G ? ? D ? c ? wherein ? is optical wavelength and ? ? ? D ? ? G ? ? D = 0.5 ? C s ? ( r R 2 ) 2 ? ? ? ? L c - 0.

Abstract: A fiber wrap and a method of rotating the fiber wrap without twisting a data cable are disclosed. The fiber wrap includes a sun gear, a sun cylinder coupled to the sun gear, a planetary gear in contact with the sun gear, a planetary cylinder coupled to the planetary gear, an outer housing in contact with the planetary gear, and a data cable coupled to the sun cylinder, the planetary cylinder, and the outer housing. The maximum bend radius of the data cable is determined by the equation: 2 ? ?? ? ? D ? ? G ? ? D ? c ? wherein ? is optical wavelength and ? ? ? D ? ? G ? ? D = 0.5 ? C s ? ( r R 2 ) 2 ? ? ? ? L c - 0.

Abstract: An electromagnetic transmission and reception system comprises a transmitter section and a receiver section. The transmitter section has a first signal source, a second signal source at a lower frequency than the first signal source, and means for generating from the first and second signal sources a plurality of signals with fixed frequency spacing derived from the second signal source frequency. One or more pairs of the plurality of signals are selected, and for the or each pair, the signals of the pair are combined to derive an output signal having a frequency derived from the difference between the frequencies of the signals of the pair. The receiver section combines a received signal, which comprises a received version of the output signal, with a local oscillator signal for frequency down-conversion of the received signal. This local oscillator signal is generated by the transmitter section.