Separate excitation of the characteristic waves in the ionosphere results in two orthogonal propagation channels on the same frequency, which may be used in diversity and multiple-input, multiple-output (MIMO) systems. In this article, a method to measure the isolation between these paths is proposed and demonstrated in a near vertical incidence skywave (NVIS) experiment at a frequency of 7 MHz over a 105-km distance. Characteristic wave isolation exceeding 25 dB is measured during "Happy Hour": the interval when the propagation path just opens or closes and only the extraordinary wave propagates.
|Number of pages||12|
|Journal||IEEE Antennas and Propagation Magazine|
|Publication status||Published - 1 Jun 2015|
- Dipole antennas
- Antenna measurements
- Frequency measurement
- Radio transmitters