• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.20 no.2
• /
• pp.245-252
• /
• 2016

In this paper, the design of a double-dipole quasi-Yagi antenna (DDQYA) with a gain over 7 dBi at 1.70-2.70 GHz band is studied. The proposed DDQYA consists of two strip dipoles with different lengths and a ground reflector, which are connected trough a coplanar stripline. The length of the second dipole is adjusted to increase the gain in the low frequency band, whereas a rectangular patch director is appended to the DDQYA to enhance the gain in the middle and high frequency band. The effects of the length of the second dipole, and the length and width of the director on the antenna performance are analyzed, and final design parameters to obtain a gain over 7 dBi are obtained. A prototype of the proposed DDQYA is fabricated on an FR4 substrate, and the experimental results show that the antenna has a frequency band of 1.60-2.86 GHz for a VSWR < 2, and measured gain ranges 7.2-7.6 dBi at 1.70-2.70 GHz band.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.49 no.6
• /
• pp.63-70
• /
• 2012

This paper discussed on the directive gain improvement method of the U-type ultra wide-band(UWB) planar patch antenna model with CPW feeding. For directive gain improvement, the U-type printed patch antenna model with CPW feeding is reconstructed as a microstrip structure by adding a reflection plane with aperture slot. The reflection coefficient of the reconstructed antenna is less than -6.5 dB(VSWR < 3.3) to the characteristic impedance of $50.08{\Omega}$ and showed the directive radiation patterns with the directive gain of 7.5 dBi ~ 10.1 dBi, the front-back ratio of 17.8 dB ~ 28.7 dB and the range of -3dB radiation angle over ${\pm}30^{\circ}$ to the main beam direction of ${\theta}=0^{\circ}$.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.21 no.2
• /
• pp.252-258
• /
• 2017

In this paper, the bandwidth and gain enhancement of a double-dipole quasi-Yagi antenna (DDQYA) using a modified balun and two directors is studied. The proposed DDQYA consists of two strip dipoles with different lengths, a ground reflector, which are connected through a coplanar strip line, and two directors. The modified balun is used to increase the bandwidth, whereas two directors are appended to the DDQYA to enhance the gain in the middle and high frequency band. The effects of the length and width of the first director on the antenna performance are analyzed, and final design parameters to obtain a gain over 7 dBi at 1.60-2.90 GHz band are obtained. A prototype of the proposed DDQYA is fabricated on an FR4 substrate, and the experimental results show that the antenna has a frequency band of 1.57-3.00 GHz for a VSWR < 2, and measured gain ranges 7.1-7.8 dBi at 1.60-2.90 GHz band.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.14 no.3
• /
• pp.304-311
• /
• 2003

In this paper, we present the 2.4 ㎓ and 5 ㎓ dual band antenna fur access point of WLAN(Wireless Local Area Network). The proposed antenna must have equal gains in both frequency bands to accept two services. We proposed using collinear array to compensate gain difference for two different frequency bands. Simulation results using 3D simulation program, CST MWS(Microwave Studio), for dual band antenna with collinear away show that the maximum gain is about 4.7 dBi at 2.4 ㎓, 5.2 dBi at 5.7 ㎓. We got additional gain of about 2.1 ㏈ with collinear array for 2.4 ㎓ in measurement. Measured results for the dual band antenna with collinear array show applicable performances for access point of wireless LAN.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.13 no.2
• /
• pp.341-348
• /
• 2018

A WLAN dual band dipole antenna with parasitic elements and a reflector is presented for high gain operation. The parasitic elements are used for practical application and high gain operation of the radiation pattern at the WLAN dual band. The proposed antenna consists of three layers, and has dimensions of $74mm{\times}40 mm{\times}31.4mm$. From the experimental results, the achieved impedance bandwidths were 1035 MHz (2.031-3.066 GHz) and 1119 MHz (5.008-6.127 GHz), respectively. The measured maximum gain at each WLAN band was 6.69 dBi and 7.81 dBi, respectively.

• Journal of Advanced Navigation Technology
• /
• v.27 no.4
• /
• pp.447-452
• /
• 2023

In this paper, gain enhancement of a double dipole quasi-Yagi antenna using a meanderline array structure was studied. A 4×1 meanderline array structure consisting of a meanderline conductor- shaped unit cell is located above the second dipole of the double dipole quasi-Yagi antenna. It was designed to have gain over 7 dBi in the frequency range between 1.70 and 2.70 GHz in order to compare the performance with the case using a conventional strip director. As a result of comparison, the average gain of the double dipole quasi-yagi antenna with the proposed meander line array structure was larger compared to the case with the conventional strip director. A double dipole quasi-Yagi antenna using the proposed meanderline array structure was fabricated on an FR4 substrate and its characteristics were compared with the simulation results. Experiment results show that the frequency band for a VSWR less than 2 was 1.55-2.82 GHz, and the frequency band for gain over 7 dBi was measured to be 1.54-2.83 GHz. The frequency bandwidth with gain over 7 dBi increased, and average gain also slightly increased, compared to the conventional case using a strip director.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.21 no.10
• /
• pp.1855-1861
• /
• 2017

In this paper, the gain enhancement of an SDPA using a director and two parasitic patches is studied. The modified balun is used to increase the bandwidth, whereas the director and two parasitic patches are appended to the SDPA to enhance the gain in the middle and high frequency bands. The effects of the distance between the director and parasitic patches on the antenna performance are analyzed, and the SDPA with a gain over 7 dBi at 1.54-2.99 GHz band is designed. The proposed SDPA is fabricated on an FR4 substrate with a dimension of $90mm(L){\times}135mm(W)$ in order to validate its performance. The fabricated antenna shows a frequency band of 1.56-3.10 GHz for a VSWR < 2, and it is confirmed by measurement that gain maintains over 7 dBi in the frequency range of 1.54-3.00 GHz.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2015.05a
• /
• pp.471-472
• /
• 2015

In this paper, a design method for enhancing the gain of a series-fed dipole pair (SDP) antenna using mutiple directors is studied. Strip-type directors are located above the second dipole of the SDP antenna, and the variations of the input VSWR bandwidth and gain depending on the length of the second dipole and the number of directors are analyzed. The antenna is optimized to obtain gain > 8 dBi in the frequency range of 1.7-2.7 GHz, which has three directors in the optimum design. The optimized antenna is designed on an FR4 substrate with a dimension of 86.2 mm by 152.3 mm, and it has frequency bands of 1.67-2.79 GHz for a VSWR < 2 and 1.69-2.72 GHz for a gain > 8 dBi.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
• /
• v.14 no.2
• /
• pp.75-82
• /
• 2003

이동체 탑재형 안테나는 설치 장소의 특성상 소형화와 경량화가 필수적인 요소이다. 그러므로 이동체 탑재형 안테나의 경우 반사판형 안테나보다 마이크로스트립 어레이 안테나가 널리 쓰이고 있다. 본 고에서는 마이크로 스트립 슬롯 어레이 안테나를 설계하였다. 만족스러운 고 이득을 얻을 수 있으며 동시에 패치 소자의 개수를 줄이기 위해 패치 단일 소자가 가급적 고 이득을 낼 수 있는 구조로 설계하였다. 본 고에서 설계한 슬롯 안테나는 기생슬롯을 가진 H 자형 타입의 소자이다. 설계는 제작상의 오차를 고려하여, 운용 주파수 11.7~12.75 GHz에서 VSWR 1.8:1 이하를 목표로 하였다. 제작된 안테나의 측정결과는 11.7~12.75 GHz대역에 걸쳐 VSWR < 1.8의 만족한 결과를 보이고, 단일 소자의 시뮬레이션 이득 결과는 10 dBi를 보였으며 $4\times4$ 어레이를 했을 경우 이득은 22 dBi의 값을 보였다. 제작되어진 안테나는 추후 급전 네트웍의 최적화를 통해 상호 간섭(Mutual Coupling)을 최소화하여 효율을 최대화한다면 직접 위성 서비스를 수신하기 위한 초소형 안테나로 활용될 수 있을 것으로 기대된다.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.8 no.9
• /
• pp.1285-1291
• /
• 2013

In this paper, a double circular ring monopole antenna for wideband applications is designed and fabricated. The proposed antenna is based on a planar monopole design, and composed of double circular ring of radiating patches and ground plane to obtain the wideband characteristics. To get the optimized parameters, we used the simulator, Ansoft's High Frequency Structure Simulator(HFSS) and found the parameters that effect antenna characteristics. Using the obtained parameters, the proposed antenna is fabricated. The fabricated antenna is measured at the operating frequencies, and the return loss coefficient, gain, and radiation patterns are determined. The results of measurement, -10dB impedance bandwidth, measured return loss is 4,530 MHz(2,510-7,040 MHz) and antenna peak and average gains for the frequencies are obtained 0.71~3.38 dBi, -3.85~0.3 dBi, respectively. In case of radiation patterns, the proposed antenna displays nearly omnidirectional radiation characteristics in the E-plane, and monopole-like radiation pattern characteristics in the H-plane.