Ka-band antenna development for LMCS applications

Local multi-point communication services, LMCS, is targeted for operation around 28 GHz with an initial bandwidth of 1 GHz. Different service scenarios are under investigation, and a preliminary multi-cell configuration assumes four transmitters per site alternating between vertical and horizontal polarizations. The beam widths will, of course, depend on the cell configuration and for the above four sector case will be 90 degrees, limiting the antenna gain. The receiver antenna, at subscriber site, should therefore have higher gains, to compensate for the path loss and attenuations due to foliage, humidity, and multiple reflections. The latter also causes multipath interference, that must be eliminated or reduced to improve the coverage. A convenient approach will be to use narrow beam receiver antennas to block the multipath signals. This, in turn, again results in higher gain receiver antennas. In principle, therefore, the subscriber antennas are expected to be high gain and simultaneously low cost to increase the subscription rate.