• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.38A no.10
• /
• pp.885-892
• /
• 2013

The main advantage of ESPAR antenna is that ESPAR antenna requires only a single RF chain for reduction of transceiver's hardware complexity, as compared to conventional MIMO system. In conventional MIMO system, each data symbol is mapped to each antenna. But, each data symbol is mapped to each orthogonal basis pattern in ESPAR antenna system. In this paper, we design beamspace MIMO system using ESPAR antenna with single RF chain for MIMO system of low-complexity and low power consumption. And then, we analyze performance of beamspace MIMO according to each PSK modulation. Performance of beamspace MIMO system is similar to performance of conventional MIMO system. As a result of analyzing the performance of beamspace MIMO system using higher-order PSK modulation. we can confirm that performance characteristic of beamspace MIMO system with low complexity and low power consumption is similar to digital communication of signal domain.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.52 no.2
• /
• pp.7-17
• /
• 2015

In this paper, we propose a single antenna SSD(simultaneous single band duplex) system using turbo equalizer. The proposed system communicates simultaneously on single band. That is the proposed system is full-duplex system. The proposed system uses balanced feed network circuit to improve isolation in single antenna structure. Also, the proposed system uses RF(radio frequency) cancellation and digital cancellation to cancel self-interference. Additionally, the proposed system uses turbo equalizer to equalize ISI(inter-symbol interference) by harsh multipath fading and to collect bit errors by residual self-interference signals. By using turbo equalizer, the proposed system guarantees QoS(quality of service). In this paper, we uses Simulink simulation program to analyze performance of the proposed system. The simulation results confirm that proposed system can communicate simultaneously by using balanced feed network, RF cancellation, digital cancellation and turbo equalizer in harsh multipath channel on single band.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.12 no.6
• /
• pp.919-930
• /
• 2001

This paper presents a wideband technique of impedance and axial-ratio bandwidth which uses the stacked planar array structure through optimum design of sub-polarization generating sections and parasitic patch. So, the effect of the dual-resonance characteristic can contribute to the bandwidth expansion of single fed planar array antenna using circular polarization which doesn\`t hire previous bandwidth expansion technique. The antenna can be used as a dual-band antenna by adjusting the resonance frequencies as well, and then the antenna is designed and fabricated in the frequency band of domestic satellite-TV service. This antenna has the performance of 9.7 % impedance bandwidth and 24 dBi of antenna gain. And it has also 2.8 % and 1.4 % of 3 dB Axial-ratio bandwidth at 11.4 GHz and 11.8 GHz respectively.

• Journal of Advanced Navigation Technology
• /
• v.14 no.1
• /
• pp.11-19
• /
• 2010

In this paper, H-plane filtering-horn antenna operating at millimeter frequency band is proposed with embedded filter and three-layered dielectric lens for frequency selection and maintenance of main beam direction, respectively. The waveguide-typed filter and H-plane sectoral horn antenna are replaced with considerably size-reduced PCB substrate-typed filtering antenna using via fences and several posts. The waveguide-typed filter and H-plane sectoral horn antenna were designed in air-filled waveguide and then combined into size-reduced PCB substrate. For the control of the thickness of dielectric lens, single and multi dielectric lens have been employed. As a result of antenna gain, 8 and 13.5 dBi have been obtained at 41.5 GHz, respectively, from the simulations of single and multi-lens antennas.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.29 no.7C
• /
• pp.907-914
• /
• 2004

In this paper, we propose an application of the receiver antenna switching to an conventional adaptive modulation system and derived the optimal antenna switching threshold of the system to maximize the average transmission bit rate and analyzed its performance. Also, we compare the performances of the presented scheme with those of an adaptive modulation using the antenna selection diversity and the one with a single antenna in terms of the average number of bits per symbol and the probability of no transmission. Performance comparison results show that the proposed system has an SNR gain of 1.4 dB over the adaptive modulation using a single antenna when the average number of bits per a symbol is two and yields an SNR gain of 6 dB for maintaining the probability of no transmission at the level of 0.1.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.11 no.3
• /
• pp.379-387
• /
• 2000

In this paper, to transmit and receive the differently polarized wideband signals simultaneously with a single antenna system, the wideband, dual-frequency and dual-polarized(WDFDP) microstrip array antenna is proposed and designed. This antenna operates simultaneously at 14.25 GHz and 12.50 GHz. To extend to two dimensional array, microstrip feed line and coaxial probe through via-hole are used. The experimental results show that the proposed WDFDP microstrip antenna can be used in the compact portable terminals with a single antenna system and the characteristic of the resonators in this antenna produces a greatly enhanced bandwidth.

• Journal of electromagnetic engineering and science
• /
• v.1 no.1
• /
• pp.67-72
• /
• 2001

In this paper, the plano-convex lens antenna fed by a single patch is studied for a microwave remote-traffic monitoring sensor with constraints of small size and low cost. Measurement of an AUT (Antenna Under Test) involves the considerations of a triangular groove for matched layer and metallic shielding effects. A formulation for extracting the parameters of a piano-convex lens antenna, based on geometrical optics, is introduced using Fermat`s principle of the equi-phased ray condition. Teflon ($\varepsilon_{{\gamma}}$/ =2.0) is chosen as a material of a plano-convex lens antenna for adjustment of aberrations on the lens surfaces automatically. A fabricated plano-convex lens shows 3-dB beamwidth of 7.5 degree and side-lobe level of -29 dB with an aperture distribution of the parabolic-squared taper on pedestal. This lens supports easier integration with the planar microwave circuits by using a microstrip single patch as a primary feeder of the lens antenna.feeder of the lens antenna.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.16 no.6
• /
• pp.1075-1080
• /
• 2021

In this paper, we designed a 24.4GHz 2-channel TX and 4-channel RX patch array antenna mounted on a short-range vehicle radar system to simultaneously measure the range and speed of a single object within a single measurement cycle. The antenna was designed and fabricated using Rogers' RO4350B(ε_r=3.48, 0.5T) board. Through measurement, it was confirmed that the design specifications of antenna gain (> 10dBi or more) and radiation pattern (Elevation HPBW > 10deg.) were satisfied at 24.4 GHz frequency.

• ETRI Journal
• /
• v.23 no.1
• /
• pp.33-38
• /
• 2001

A numerical simulation and an experimental implementation of T-shaped microstrip-fed printed slot array antenna are presented in this paper. The proposed antenna with relative permittivity 4.3 and thickness 1.0mm is analyzed by the finite-difference time-domain (FDTD) method. The dependence of design parameters on the bandwidth characteristics is investigated. The measured bandwidth of twin-slot array antenna is from 1.37 GHz to 2.388 GHz, which is approximately 53.9 % for return loss less than or equal to -10 dB. The bandwidth of twin-slot is about 1.06 % larger than that of single-slot antenna. The measured results are in good agreement with the FDTD results.

• Proceedings of the IEEK Conference
• /
• 1998.06a
• /
• pp.145-148
• /
• 1998

In this paper, a microstrip antenna is designed using a rectangular patch. To find characteristics of the antenna, computer simulations of the rectangular single microstrip patch antenna are performed with changing width. And we compared the result of computer simulation with the experimental value. Through the results, we found that the 3-D FDTD method is an effective method for designing microstrip patch antenna. According to simulation the resonant point has been found it in the frequency received from GPS satellite. It is thought that make it match by adjusting the feedpoint.