Abstract :
What is the correct polarization loss, when calculating the transmission between two antennas whose gains are measured with respect to circular polarization, such as, from a ground station to a satellite? Previously published charts made assumptions, which do not quite fit this situation. We need to revisit this problem, and be made aware of the assumptions behind these charts, so that we obtain the right answer. In general, the previous charts over-estimate the loss. All these charts are correct when used in the proper situation. As a part of this discussion, the author also covers methods of measuring the gain of circularly polarized antennas. A new nomograph calculates the polarization efficiency to be used in a link budget, when the gain of the antennas have been measured with respect to a pure-polarization incident wave. A comparison is made to previous nomographs, and the assumptions made in deriving them
Keywords :
antenna testing; electromagnetic wave polarisation; gain measurement; losses; satellite antennas; satellite ground stations; antennas; charts; circular polarization; circularly polarized antenna; ground station; link budget; measured circular-polarization gain; polarization efficiency; polarization loss; pure-polarization incident wave; satellite; transmission; Antenna measurements; Antennas and propagation; Gain measurement; Loss measurement; Performance gain; Phase measurement; Polarization; Power measurement; Rotation measurement; Transmitting antennas;
