• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.20 no.12
• /
• pp.1316-1324
• /
• 2009

In this paper, cross-aperture coupled microstrip circular polarization antenna is proposed for 5.8 GHz WLAN(Wireless Local Area Network). A single antenna consists of square patch and slots are located in series feed line with $\lambda_g$/4 phase different which make current direction maximum and minimum repeatedly to generate RHCP(Right Handed Circularly Polarization). We are proposed new structure that removed the section which intersected at a right angle and were composed to four separated slots. The proposed cross slots reduce back lobe of radiation pattern and improve antenna gain. Impedance bandwidth of the manufactured $2\times2$ array antenna is from 5.67 to 5.95 GHz and the maximum radiation gain is 10.59 dBi.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.18 no.10
• /
• pp.1150-1156
• /
• 2007

In this paper, two novel subsurface antennas for remote management of underground facilities using PCS and cellular wireless network are proposed. The proposed subsurface antenna is a dual band circular patch which is inserted and molded for the protection of the antenna into a metal such as a manhole cover. The antenna is designed considering the resonant frequency shift of the antenna due to the insertion and molding. The measured return loss and receiving power of the fabricated antenna comparison with a dipole shows that two proposed subsurface antenna can be used for remote management of underground facilities using PCS and cellular systems.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.19 no.8
• /
• pp.920-926
• /
• 2008

In this paper, small epsilon negative(ENG) zeroth-order resonance(ZOR) antenna with improved bandwidth is presented. To reduce the size of ENG ZOR antenna without narrowing bandwidth, large shunt inductance is introduced by adding patterns on patch and meandered via. The effective permittivity of meandered via is less dependent of frequency than that of straight via in same size. Thus, ENG ZOR antenna with meandered via has broader bandwidth. As a result, the bandwidth of ENG ZOR antenna with meandered via is 1.38 times as broad as that of spiral ENG ZOR antenna with straight via. On the other hand, the area of ENG ZOR antenna is reduced by 64 % compared with that of conventional mushroom ZOR antenna.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.11 no.10
• /
• pp.3880-3884
• /
• 2010

In this paper, circularly polarized micro-strip GPS antenna has been designed and fabricated. In order to improve of frequency properties, patch size, corner truncated size and feed positions were simulated using HFSS simulation program. Micro-strip GPS antenna was fabricated on the FR4 substrate of dielectric constant 4.4. The fabricated GPS antenna has that center frequency is 1.575GHz and insertion loss is -34.50dB.

• Journal of information and communication convergence engineering
• /
• v.14 no.3
• /
• pp.184-190
• /
• 2016

We present experimental demonstrations of electromagnetic bandgap (EBG) structures for the wideband suppression of radiated emissions from a power bus in high-speed printed circuit boards (PCBs). In most of the PCB designs, a parallel plate waveguide (PPW) structure is employed for a power bus. This structure significantly produces the wideband-radiated emissions resulting from parallel plate modes. To suppress the parallel plate modes in the wideband frequency range, the power buses based on the electromagnetic bandgap structure with a defected ground structure (DGS) are presented. DGSs are applied to a metal plane that is connected to a rectangular EBG patch by using a via structure. The use of the DGS increases the characteristic impedance value of a unit cell, thereby substantially improving the suppression bandwidth of the radiated emissions. It is experimentally demonstrated that the DGS-EBG structure significantly mitigates the radiated emissions over the frequency range of 0.5 GHz to 2 GHz as compared to the PPW.

• Journal of Advanced Marine Engineering and Technology
• /
• v.31 no.7
• /
• pp.857-862
• /
• 2007

A novel compact ultra wideband(UWB) antenna for UWB application is proposed in this paper. The proposed antenna with $22mm{\times}26mm{\times}1.6mm$ covers the entire UWB bandwidth and has band notch characteristic for the frequency band of $5.15{\sim}5.825GHz$ limited by WLAN. The antenna has a concaved ground plane and staircase shape patch to achieve the wide bandwidth, and has an U shape slot with $\lambda/4$ length to notch the band. The return loss and group delay of the proposed antenna are measured.

• Journal of Advanced Navigation Technology
• /
• v.6 no.2
• /
• pp.113-118
• /
• 2002

In this paper, an internal GPS antenna for mobile phones is designed and fabricated. For the miniaturization of the antenna, high permittivity dielectric substrate((${\varepsilon}_r$=90) and small ground plane ($13mm{\times}13mm$) are used. To increase the receive gain, the antenna is composed with LNA(Low Noise Amplifier). Results of the manufactured antenna($13mm{\times}13mm{\times}8mm$) show that the maximum antenna gain is about 12 dBi, the axial ratio is less than 3 dB, and the current consumption of LNA is less than 4 mA.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.14 no.5
• /
• pp.542-548
• /
• 1989

Rectangular microstrip antenna array using Chebyscheff polynomial is designed. The required relative currents in the rectangular microstrip array antenna are 1:2:2:1. The input admittance and returen loss of array antenna are calculated from transmission line model circuit include feed line. The calculated resonant frequency valused are in good agreement with measured values. Also, the sharp beam scanning characteristic of perfect electronic method is presented.

• Journal of the Korean Institute of Navigation
• /
• v.23 no.2
• /
• pp.61-66
• /
• 1999

It is being more and more difficult to suppress emissions from electronic products using PCB(Printed Circuit Board) to the limit. Therefore, the exact evaluation of the emission from PCB has been more important to reduce the required time and the cost at the design phase of the products, especially on board ship's equipments. This research has evaluated the emission radiated from PCB based on the theoretical approach of SDA(Spectral Domain Analysis), which is available to analyze microwave stripline, coplanar line, patch antenna, etc. According to the theoretical results, it has been clearly shown that the emission radiated from PCB is reduced as the thickness of PCB is thinner, the permittivity of PCB is higher, the length of stripline is shorter, and the frequency is lower.

• KIEE International Transactions on Electrophysics and Applications
• /
• v.4C no.6
• /
• pp.306-309
• /
• 2004

This paper presents a new active antenna consisting of a microstrip patch for the passive radiator, a mixer for frequency conversion, a voltage controlled oscillator (VCO) and a phase detector for phase control. The microwave signal frequency has been converted into intermediate frequency (IF) on the antenna elements by the mixer. The active antenna consists of two ports, the IF port has a transmitted IF signal via power combined to the baseband and the dc control port is under the control of the phase-detector. The input voltage of the VCO is controlled by the phase detector. The scan range of the array is determined by the phase detector and the VCO and is obtained between 30$^{\circ}$ and - 30$^{\circ}$