Therefore, we attempted to gather energy using a parasitic radiator directly from the main antennas of base stations and repeaters, which radiate RF signals.
The parasitic radiator couples the RF power, which mostly does not contribute to the main performance of the main radiator, as the harvested signal is radiated out of a 3-dB beam width of the main radiator.
Figure 1(b) shows the two-turn loop structure of the parasitic radiator in detail as designed with a dielectric substrate, which is not shown in the figure to clarify the loop structure.
The parasitic radiator is designed with FR4 substrate ([[epsilon].
Figure 3 shows the performance variation of the main radiator according to the height of the parasitic radiator in the simulation.
As shown in Figure 4(b), the main radiator has a port named Port 1, and the parasitic radiator is fed by Port 2 into one end of the loop.
The measured reflection coefficient of the main and the parasitic radiator according to the height of the parasitic radiator is presented in Figure 5.
The coupling coefficient improves as the height of the parasitic radiator increases, and the coupling coefficient is about -12 dB when [h.
For the next step, the horn connected to the signal generator was exchanged with the main radiator without the parasitic radiator.
This antenna is designed to gather RF energy using a parasitic radiator from the main radiator of a variety of wireless transmitters (or transceivers) as used in the Korean WCDMA service.
The fabricated main radiator without the parasitic radiator has a gain of 8.