• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.41 no.7
• /
• pp.81-88
• /
• 2004

In case of mechanical down tilting, a horizontal pattern is distorted and beam width widens whenincreasing tilt angle, which causes an expansion of hand off region and burden base station equipment. In contrast, electrical down tilting has advantage that horizontal HPBW is kept constant with down tilting. In this paper, based on a phased array technology, dual polarized base station antenna with electrical down tilting was developed at 800MHz band. The antenna has down tilting range of 0$^{\circ}$ to 14$^{\circ}$, and 15㏈i gain. We use stacked microstrip patch as a radiated element and apply balanced feed technique to improve isolation between ports and discrimination of cross polarization. The effect of electrical down tilting was verified by field test.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.27 no.7
• /
• pp.612-619
• /
• 2016

In this paper, a dual band electrical beam tilting array antenna with bi-directional directivity is designed. Radiating element operates at dual-resonance frequencies and is designed as planar dipole using PCB. In order to tilt the main beam, the phase delay line is designed by use of only the phase shifting line of a $50\Omega$ microstrip line for broadband. The designed antenna has tilting angle of $0^{\circ}$ to ${\pm}8^{\circ}$. For validation of the designed antenna specification, the array antenna is fabricated and the performances are measured. Comparison between theory and experiment shows good agreement.

• Journal of Advanced Navigation Technology
• /
• v.25 no.5
• /
• pp.384-389
• /
• 2021

An optimal ground station (GS) antenna pattern design method for network-based UAV command and control communication systems considering complexity and performance is presented. The GS antenna consists of multiple side sectors and one upward sector. The antenna gain for each vertical/horizontal angle of the GS antenna according to the change of antenna design parameters such as the number of sectors, horizontal and vertical beam-width, and tilt-angle is modeled, and the effect of the parameter changes on the signal-to-noise ratio (SNR) distribution in the virtual three-dimensional space is analyzed. It is observed that the tilt-angle of the side sectors has the greatest effect on the performance, and the longer the distance between GSs, the higher the maximum altitude and the smaller the number of side sectors, the tilt-angle should be lower. In addition, it is observed that the wider vertical beam-width of the side sector is advantageous in maximizing the lowest SNR, but narrow vertical beam-width is advantageous in maximizing the average SNR.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.47 no.7
• /
• pp.29-35
• /
• 2010

The cooperative transmission between sectors in next generation communications standards, e.g., 3GPP LTE-Advanced and IEEE 802.16m, has become an important research issue. Hence methods to decide the optimal antenna tilting angle in cooperative transmission between sectors are needed. This paper proposes methods to decide the optimal antenna tilting angle in cases of non-cooperative and cooperative transmissions between sectors. The proposed methods use an objective function that maximizes the cell average log rate or the cell average rate for users distributed uniformly within the radius of the sector. Also, the objective function which maximizes the cell average rate determined by adaptive modulation and coding (AMC) used in actual cellular systems is considered. When the cell average rate becomes the objective function, the system rate efficiency increases significantly for both cooperative and non-cooperative transmission. When the cell average log rate and the AMC rate become the objective functions, an optimal antenna tilting decision method which effectively increases the efficiency of cell boundary users is discussed.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.14 no.2
• /
• pp.202-208
• /
• 2003

In this paper, we proposed a microstrip patch array antenna for DBS reception which had high gain and high tilted angle through mutual coupling driver patch to parasitic patch in H-plane edge and broadside direction in different layers. It was designed and fabricated in 16$\times$8 array by using low cost polyester based copper-clad laminate and foam instead of high cost dielectric substrate. It had gain of 22.9 dBi, beamwidth of 4.6$^{\circ}$, and tilted angle from broadside direction of 43.9$^{\circ}$.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.12 no.5
• /
• pp.705-712
• /
• 2001

In this paper, a new type of aperture coupled microstrip patch antenna with tilted-beam based on the principal of the dipole yagi antenna is proposed and investigated experimentally. Its configuration is composed by 3 types of patches; reflector, driver, and director. Tilted beam patterns are effected by many parameters as those of dipole yagi antenna; sizes of the patches, gaps between the patches, characteristics of the substrates, feeding method and etc. Therefore, in this paper, the effects of varying design parameters of this antenna are studied with a goal of enhancing the gain and tilting the beams. A microtrip patch antenna with tilted beam based on performance trade-offs is designed and fabricated. Measured and simulated results for return loss and radiation patterns are presented. It has 45$^{\circ}$ tilted beam and very close to simulation beam pattern at resonant frequency, 2.58 GHz.

• Journal of Advanced Navigation Technology
• /
• v.7 no.2
• /
• pp.101-107
• /
• 2003

In this study, we provide a single element log-periodic antenna that the feeding networks and array structures are aperture coupled and series dipole array type. We made the antenna for direct receiving the Moogoongwha satellite broadcasting signal. The transmission power was able to feed the patch dipole in series due to lay perpendicularly 8 series patch dipole on tapered slot. The patch dipole radiation pattern which fed in series power, make the main beam direction up $37^{\circ}{\sim}42^{\circ}$ within the BS/CS bandwidth. The main beam gain was measured 9.31~11.03 dBi. Using 32 elements to array the elements properly, we acquire $4{\times}8$ array structure on limited PCB board. As a result, it has been found that the new planar DBS antenna structure have high gain over 10dBi and acceptable elevation angle over 42 degree, and we can apply this result to commercial DBS reception antenna manufacturing.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.14 no.10
• /
• pp.1071-1078
• /
• 2003

In this paper, the planar, compact, and broadband phased array antenna system for IMT-2000 applications has been investigated. Two methods far designing a low-cost and low-complex beam-farming network are proposed. First, a new compact and broadband phase shifter with continuously controlled phase bits is designed by using parallel coupled lines. Second, its equivalent phase delay line is suggested to be capable of replacing the complex phase shifter with a reference phase bit on a phased array antenna. For the purpose of achieving the broadband system, in addition to the broadband phase shifter, a wide-slot antenna with a ground reflector is utilized as an element antenna. Therefore, the phased array antenna system has achieved compact size, broad bandwidth, and wide steering angle, although it has low complexity and low fabrication cost. The 3${\times}$1 phased array antenna system has a compact size of 1.6 λ${\times}$ l.6 λ, which is the sufficient ground plane of the wide-slot antenna. Experimental results present that the S$\_$11/ has less than 15 dB within the band and its radiation patterns on an E-plane have the capability of steering an antenna beam from -29$^{\circ}$to +30$^{\circ}$.