RadioLink Networks FAQ

  • What is RLN's unique technology?
  • < >The first part of RLN's technology to receive patent protection is "Aligned duplex antennae with high isolation". The US patent is 7,286,096, available from USPTO and FreePatentsOnline.

    Abstract

    Integrating dual antennae into a single rigid assembly guarantees parallel alignment between the antennae and provides higher isolation with lower insertion loss than duplexing methods can achieve through a single antenna. The resulting higher performance at lower cost can benefit two-way communication systems using time division duplexing, frequency division duplexing, or polarization division duplexing; or combinations of these methods.

    RLN's patent was granted unusually quickly, only 15 months from the final application to the Notice of Allowance. Moreover, all 20 claims were granted without a single office action.

     

  • What are the advantages of RLN's "Aligned duplex antennae with high isolation"?
  • < >Because RLN antennas are offset fed, the feedhorn and its support don't obstruct the beams. Our aperture efficiency is 0.75, versus 0.55 for a conventional center-fed parabolic dish. Because one antenna section is used for transmission while another antenna section is used for reception, there is no transmit/receive diplexer with its inherent signal losses (0.9.dB and 2.5.dB for K-band). RLN's higher aperture efficiency and the lack of diplexer losses offset the antenna gain being reduced because each antenna section is only part of the total area.Because each of the duplex antennas has half the area, its beam angle is 50% wider than that of the equivalently sized single parabolic dish. Our higher aperture efficiency and lack of the diplexer compensates for the reduced antenna gain. To have a wider beam at equivalent gain is an advantage at higher frequencies where the beam widths shrink below 1 degree. It is difficult to make a mounting so rigid that high winds don't interrupt service when they bend it by that small amount.Transmit-to-receive interference is no longer limited by the diplexer isolation, but by feedhorn off-axis response, free-space loss, and diffraction over the ridge between adjacent antenna sections. Conservative calculations predict large isolations:
       64.cm*32.cm   96.cm*48.cm   127.cm*64.cm 
    15.GHz: 67.7.dB 72.6.dB 76.2.dB
    18.GHz: 69.9.dB 74.9.dB 78.5.dB
    23.GHz: 72.9.dB 78.0.dB 81.6.dB
    26.GHz: 74.4.dB 79.5.dB 83.2.dB
    38.GHz: 79.2.dB 84.4.dB 88.0.dB
    Modification of the ridge promises additional isolation.Because the transmit/receive isolation is frequency independent, the same frequency band can be used for transmit and receive, doubling the bandwidth available from a given segment of spectrum.Because there is no diplexer, the input amplifier and power amplifier can be placed directly at the feedhorns, eliminating the need for waveguide.With electronics at the feedhorns, both polarizations can be received from or transmitted to each feedhorn using simple launchers. Because the transmit and receive beams are not coaxial, backscatter is severely attenuated.Can RLN's technology be used for mesh networking?
  • Point-to-point backhaul links do form a network, but with lower branching factors than is usually implied by "mesh networking".

    The highly directional antennas used by a point-to-point link span distances orders of magnitude farther than can be acheived by omnidirectional antennas with the same transmitter power at the same frequencies. Adding redundant point-to-point connections requires additional directional antennas and equipment at both nodes; it is sometimes done, but is usually not cost effective.

     

  • Can RLN's technology be used MIMO?
  • Yes; it is covered by claim 16 of the patent.