Design of Dual Band, High Gain, Close Spaced Frequency Tunable Antenna
Location
Nessmith-Lane Atrium
Session Format
Poster Presentation
Research Area Topic:
Engineering and Material Sciences - Electrical
Abstract
Much attention has been paid to Frequency-tunable antenna since the use of frequency spectrum increases. Frequency tunable has been achieved using various methods such as changing the geometry shape and etc. Among those, the use of varactor has been proven to be the most convenient and efficient. With the ability to adjust operating band from crowded spectrum to empty one, frequency tunable antenna can improve the transmission/reception. One common application is multiple input-multiple output system (MIMO), which usually requires multiple antennas or digital video broadcasting-handheld (DVB-H) system that requires different frequencies for different channels. Recent research shows that frequency tunable antenna can solve the signal fading issue effectively. Signal fading usually occurs by the back scattering of the propagation and frequency tunable antenna can enhance the signal strength in specific frequency in order to overcome the signal cancellation and establish stable connectivity. In this research, a design of a dual band, electrically small, close spaced frequency tunable antenna is presented.
The antenna consists of two main parts, the top structure and varies values of capacitors at the bottom. Two helical antennas with a common center and each of the helical antenna is fixed at one turn at different heights. These helical antennas are the directors that generates different bands according to their height and lengths. The directors are twisted in at different pitch angles to avoid radiation interference with each other at the respective bands. The driver is folded to match the antenna impedance and minimized the close spacing effect.
The ability of tuning is achieved by using varactor BB640. By applying the varactor onto the directors, different electrical length of the antenna is achieved by changing the voltage that supplied to the varactor. The proposed antenna has a total tunable bandwidth of 19.26% ranging from 1.411 GHz to 1.566 GHz for the first band and 1.576 GHz to 1.710 GHz for second band. High realized gain of at least 7.5 dBi across the whole operating band with peak realized gain of 10 dBi is achieved . The antenna has a dimension of 14.04 mm (0.07) 18.41 mm (0.09) ÌÑ 42.96 mm (0.22).
Presentation Type and Release Option
Presentation (Open Access)
Start Date
4-16-2016 2:45 PM
End Date
4-16-2016 4:00 PM
Recommended Citation
Chen, Jinxi, "Design of Dual Band, High Gain, Close Spaced Frequency Tunable Antenna" (2016). GS4 Georgia Southern Student Scholars Symposium. 98.
https://digitalcommons.georgiasouthern.edu/research_symposium/2016/2016/98
Design of Dual Band, High Gain, Close Spaced Frequency Tunable Antenna
Nessmith-Lane Atrium
Much attention has been paid to Frequency-tunable antenna since the use of frequency spectrum increases. Frequency tunable has been achieved using various methods such as changing the geometry shape and etc. Among those, the use of varactor has been proven to be the most convenient and efficient. With the ability to adjust operating band from crowded spectrum to empty one, frequency tunable antenna can improve the transmission/reception. One common application is multiple input-multiple output system (MIMO), which usually requires multiple antennas or digital video broadcasting-handheld (DVB-H) system that requires different frequencies for different channels. Recent research shows that frequency tunable antenna can solve the signal fading issue effectively. Signal fading usually occurs by the back scattering of the propagation and frequency tunable antenna can enhance the signal strength in specific frequency in order to overcome the signal cancellation and establish stable connectivity. In this research, a design of a dual band, electrically small, close spaced frequency tunable antenna is presented.
The antenna consists of two main parts, the top structure and varies values of capacitors at the bottom. Two helical antennas with a common center and each of the helical antenna is fixed at one turn at different heights. These helical antennas are the directors that generates different bands according to their height and lengths. The directors are twisted in at different pitch angles to avoid radiation interference with each other at the respective bands. The driver is folded to match the antenna impedance and minimized the close spacing effect.
The ability of tuning is achieved by using varactor BB640. By applying the varactor onto the directors, different electrical length of the antenna is achieved by changing the voltage that supplied to the varactor. The proposed antenna has a total tunable bandwidth of 19.26% ranging from 1.411 GHz to 1.566 GHz for the first band and 1.576 GHz to 1.710 GHz for second band. High realized gain of at least 7.5 dBi across the whole operating band with peak realized gain of 10 dBi is achieved . The antenna has a dimension of 14.04 mm (0.07) 18.41 mm (0.09) ÌÑ 42.96 mm (0.22).
