• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.41 no.4
• /
• pp.41-47
• /
• 2004

In this paper, we analyze the microwave characteristics of traveling-wave electro-absorption modulator (TW-EAM) considering the microwave feedline and the impedance mismatch. The TW-EAM is analyzed by using the equivalent circuit model. The capacitance and the inductance of the equivalent circuit are evaluated by using 3-dimensional finite difference time domain (FDTD) method, while the microwave feedline is analyzed by momentum method. In a viewpoint of microwave characteristics, we present the effect of the structure and the length of microwave feedline.

• Proceedings of the IEEK Conference
• /
• 2003.07a
• /
• pp.302-305
• /
• 2003

In this paper, a feedline which is a shape of a fork is designed to improve a bandwidth of the microstrip slot antenna. To determine design parameters of the feedline, the characteristics of the microstrip slot antenna is analyzed by changing design parameters of the feedline. The microstrip slot antenna with the feedline of a shape of a fork has a wide band, from 1.7 GHz to 6.1 GHz for VSWR $\leq$2.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.41 no.8
• /
• pp.87-92
• /
• 2004

In this paper, a microstrip slot antenna with a fork-shaped feedline is designed and fabricated. To obtain a broadband characteristic of a wide slot antenna a feedline is transformed into a shape of a fork, and a size of the slot and offset - length is varied. As the characteristics of the slot antenna as the function of design parameters are analyzed, a broadband microstrip slot antenna is designed. The microstrip slot antenna with a fork-shaped feedline is fabricated and its measured bandwidth is from 1.65 GHz to 6.20 GHz for VSWR$\leq$2.

• Journal of the Institute of Electronics Engineers of Korea TE
• /
• v.37 no.2
• /
• pp.69-74
• /
• 2000

The bandwidth of microstrip slot antenna with T-shaped feed line was a wider than one of the conventional feeding structure. When the slot antenna with bi-directional radiator wants to radiate only one direction, the reflector must be set up seperately. But this antenna doesn't need set up reflector. And then we proposed to a new method of a directional slot radiator with a cross-shaped feedline including the reflector using 2-layers dielectric materials. It is calculated waves and electric field distribution in the time domain by using FDTD method. We also are calculated return loss, VSWR, input impedance, and radiation pattern in the frequency domain by Fourier transforming the time domain results, respectively. It was found that the bandwidth of this antenna changes as length($\I_s$) and width($\W_s$) of slot, length of the horizontal feedline($\I_d$), length of the vertical feedline($\I_u$) and offset sensitively. After optimizing the parameters of design, the maximum bandwidth was measured as 1,850MHz at the center frequency 2.5 GHz.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.14 no.8
• /
• pp.878-883
• /
• 2003

New feeding structures using linearly and exponentially tapered lines to planar microstrip resonators are proposed. These can overcome the design problems from coupling losses and impedance mismatching by increasing the coupling efficiency. The variation of its feeding angle is evaluated for the insertion loss and bandwidth and the feedline length is optimized at ${\lambda}_g$/2. The ring resonators and patches fed by the tapered line have been designed and implemented. The experimental results show that the insertion loss is enhanced by about 7 dB. Both rings and antennas are better matched, without disturbing the single-mode resonance or distorting their radiation pattern

• Proceedings of the Korean Nuclear Society Conference
• /
• 1999.05a
• /
• pp.186-186
• /
• 1999

• Journal of electromagnetic engineering and science
• /
• v.10 no.3
• /
• pp.150-157
• /
• 2010

We proposed a $4{\times}8$ array antenna with aperture-coupled patch antenna elements. The antenna was designed for 60 GHz operation and fabrication on the low-temperature cofired ceramic(LTCC) substrate($\varepsilon_r$=5.8). The feedline with the stub was designed to enhance the radiating element bandwidth and the transition characteristics between the waveguide (WG) and microstrip line(MSL). Through the optimization of the antenna and feedline geometry, the antenna gain and the performance of the 10 dB bandwidth were 20.2 dBi and 13 % up, respectively. The measured results agreed with the simulated ones.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.38 no.1
• /
• pp.27-33
• /
• 2001

This article describes an observation that the aperture coupling mechanisms in the aperture coupled microstrip antenna can be divided into two categories, cavity and parasitic types, depending on the separation between the microstrip patch and the ground plane. The similar phenomenon was observed in the relatively simple gap coupled microstrip antenna. The specific characteristics between two coupling mechanisms is discussed.

• Proceedings of the IEEK Conference
• /
• 2000.07a
• /
• pp.183-186
• /
• 2000

We analyzed the cross-shaped microstripline-fed slot antenna with the reflector using FDTD(Finite-Difference Time-Domain) method in this paper. The proposed antenna uses RR Duroid-5880 substrate(relative permittivity 2.2 and height(1.578 mm) of dielectrics), and compares the optimized results of other kind substrates. The maximum bandwidth of the proposed antenna is from 1.91 GHz to 5.21 GHz, which is approximately 1.437 octave for the VSWR $\leq$ 2. It was found that the bandwidth of the antenna depend highly on the length of the horizontal and vertical feedline as well as the offset position of the feedline. The experimented data for the VSWR and the radiation pattern of the antenna are also represented.

• Proceedings of the Korean Nuclear Society Conference
• /
• 2003.05a
• /
• pp.174.1-174.1
• /
• 2003