| dc.description.abstract | Electronic devices use a small DC (Direct Current) sources such as batteries with a limited lifetime. It is encouraging
to produce new ideas and technologies that can be used from external sources which we commonly refer to as energy harvesters.
Rectenna is a device that can be used to harvest electromagnetic waves, an antenna as a wave catcher and integrated with a
rectifier or rectifier in the form of media to convert AC (alternating current) to DC voltage. Rectifiers consist of parallel series
arrays between capacitors and diodes. High frequency and low level according to the special type of schotkky diode. Receiver
antennas require large gain, one of which is a directional type antenna, which is a helical antenna spiral axial mode with a ground
plane. To get a voltage greater than the input voltage, it is necessary to use Cockroft-Walton voltage multiplier rectifier which
can create high voltage at low currents at a low cost. The proposed design and fabricated axial helix mode antennas have
parameter values that have met the standard of working an antenna in general. The results of fabrication have GSM working
frequency at 1900 MHz with return loss parameters of -20.3 dB and VSWR of 1.22. In designing the rectenna an antenna is
needed that can work on GSM frequencies so that the frequency of 1900 MHz can be used on this device. While the analysis of
the results of testing the DC voltage output of the two circuits shows different results, in general, the rectifier with matching
impedance circuit produces a higher voltage than the rectifier without matching impedance. The output voltage is 85.3 mV with a
distance of 100 m, 79.1 mV with a distance of 200 m, and 22.7 mV at a distance of 300 m, the rest of the rectenna cannot receive
enough power level to be converted into DC voltage. The rectenna developing is very dependent on the effectiveness of power
transfer from the antenna to the rectifier so that it also needs a topology matching type L matching impedance. The L matching
impedance circuit produces a better DC voltage than without using a matching circuit. The results test prove that electromagnetic
waves can be converted to DC with a value reaching +85.3 mV. | en_US |
