• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2003.06a
• /
• pp.1647-1650
• /
• 2003

The Objective of this work was to design Surface Antenna Structure (SAS) and investigate fatigue behavior of SAS that was asymmetric sandwich structure. This term, SAS, indicates that structural surface becomes antenna. Constituent materials were selected considering electrical properties, dielectric constant and tangent loss as well as mechanical properties. For the antenna performance, SSFIP elements inserted into structural layers were designed for satellite communication at a resonant frequency of 12.5 GHz and final demonstration article was 16${\times}$8 array antenna. From electrical measurements, it was shown that antenna performances were in good agreement with design requirements. In cyclic 4-point bending, flexure behavior was investigated by static and fatigue test. Fatigue lift curve of SAS was obtained. The fatigue load was determined experimentally at a 0.75(1.875kN) load level. SAS concept is the first serious attempt at integration for both antenna and composite engineers and promises innovative future communication technology.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2003.06a
• /
• pp.802-805
• /
• 2003

Structural surface becomes an antenna. The integration of antennas into structural body panels is a new high payoff technology. It emerged from the need to improve structural efficiency and antenna performance. In this paper, we developed new design concept for the structural surface which transmits and receives the electromagnetic signals, and it is termed Surface-Antenna-Structure (SAS). Design procedure was presented including structure design. material selection and design of antenna elements, which was processed according to the communication with KORSAT satellite at Ku-Band (12.25-12.75 GHz). The final demonstration article was 350$\times$200$\times$7.5mm flat antenna panel. Experimental results for antenna performances were in good agreements with design requirements. Also structural analysis was performed with SAS. estimating stress distributions under simply supported condition with Laminated Plate Theories and Wavier Solutions. The SAS concept can be extended to give a useful guide to manufacturers of structural body panels as well as antenna designers. promising innovative future communication technology.

• Proceedings of the Korean Society For Composite Materials Conference
• /
• 2003.04a
• /
• pp.108-111
• /
• 2003

The Objective of this work was to design Surface Antenna Structure (SAS) and investigate fatigue behavior of SAS that was asymmetric sandwich structure. This term, SAS, indicates that structural surface becomes antenna. Constituent materials were selected considering electrical properties, dielectric constant and tangent loss as well as mechanical properties. For the antenna performance, SSFIP elements inserted into structural layers were designed for satellite communication at a resonant frequency of 12.5 GHz and final demonstration article was $16\;{\times}\;8$ array antenna. From electrical measurements, it was shown that antenna performances were in good agreement with design requirements. In cyclic 4-point bending, flexure behavior was investigated by static and fatigue test. Fatigue life curve of SAS was obtained. The fatigue load was determined experimentally at a 0.75(1.875kN) load level. SAS concept is the first serious attempt at integration for both antenna and composite engineers and promises innovative future communication technology.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.13 no.5
• /
• pp.860-867
• /
• 2009

In this paper, we designed the array antenna for FMCW radar in X - band frequency, and we chose stacked structure for improvement of narrow bandwidth. The array antenna is implemented on the circuit board which is relative permittivity 2.33 and the stacked patchs are designed on the circuit board which is relative permittivity 4.6. A Foam which has a similar permittivity of air is added to keep the particular gap between array antenna and the stacked patch. The result of array antenna has characteristics that a half-power beam width is $10.6^{\circ}$ and antenna gain is 18.70 dBi and bandwidth is 1.25GHz at the design frequency of 9GHz. The result of the array antenna with the stacked structure has that the half power beam width is $15.17^{\circ}$ and the antenna gain is 15.85dBi and bandwidth is 2GHz. It is needed to improve the antenna gain as keeping bandwidth in same level.

• Proceedings of KOSOMES biannual meeting
• /
• 2007.11a
• /
• pp.211-214
• /
• 2007

In this paper, we have designed microstrip antenna if 800[MHz] band It will be able to integrate TRS(Trunked Radio System), GSM(Global System for Mobile telecommunication) band including the CDMA(Code Division Multiple Access) band we designed repeater and a base station antenna which is possible at the ship and marine of safety. It is improves a narrow bandwidth problem of microstrip antenna. It had U-shaped feeding structure at a rectangular patch And ground or feeding structure used between dielectric constant(${\varepsilon}_T$ = 2.1), patch or feeding structure used between dielectric constant(${\varepsilon}_T$ =1). So it used a duplex resonance effect Designed frequency bandwith(V5WR 2:1) if the antenna showed good characteristic of $780[MHz]{\sim}1.83[GHz]$ to 2.61[GHz]. Also the E-plan and H-plan all profit 9.4[dBi] above, the 3[dB] beam width showed the characteristic over the E-plan and H-plan $60^{\circ}$ to be improved.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.42 no.3 s.333
• /
• pp.33-38
• /
• 2005

In this paper, we have designed and fabricated a hybrid ring coupler to prove the fabrication possibility of various passive components, applying millimeter wave using newly proposed transmission lines, i.e. BAMLs. The characteristics of the fabricated hybrid ing coupler were a the S31(coupling) of 3.58 dB, the S21(thru) of 3.31 dB at the 60 GHz center frequency, the S11(return loss) over 16.17 dB, S41(isolation) over 55 dB at 61 GHz, and the phase difference between port 2 and port 3 of $180{\pm}loat$ 60GHz. In order to reduce the size of hybrid ring coupler, we designed the hybrid ring coupler which inserts a slow wave structure. With this structure, we were able to reduce the hybrid ring coupler by $33\%$ area.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.49 no.1
• /
• pp.68-72
• /
• 2012

In this paper, highly linear power amplifier using bandpass filter based on metamaterial and Composite Right- / Left-Handed (CRLH) structure is proposed. The proposed bandpass filter consist of the series capacitor, series microstrip line and the parallel inductor, parallel microstrip line. The insertion loss is minimized at operation frequency and the $2^{nd}$ harmonic is suppressed by the bandpass filter using the CRLH structure. And we improved the Adjacent Channel Leakage Ratio (ACLR) using the characteristic of the proposed bandpass filter. At 2.14 GHz, we have obtained the output power of 38.83 dBm, the $2^{nd}$ harmonic of .61.33 dBc, the $3^{rd}$ IMD of .54.67 dBc, and ACLR of .51.33 dBc at 5 MHz offset, -56.50 dBc at 10 MHz offset, respectively.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.15 no.2
• /
• pp.111-118
• /
• 2016

This paper presents an X-band (9.375 GHz) $1{\times}2$ array microstrip antenna which is capable of active beam compensation for installation of an unmanned aerial vehicle (UAV). First of all, a basic $1{\times}2$ array microstrip antenna incorporated with wilkinson power divider was designed and performance of the array antenna was verified. Next, to verify beam steering performance of the designed array microstrip antenna, we fabricated a phase shifter, and the wilkinson power divider as module structure and measured characteristics of beam steering according to phase shifting. The main lobe is 0.6 dBi at $0^{\circ}$, and the side lobe decreased 18.8 dB. The reliable radiation pattern was achieved. Finally, an active beam steering microstrip array antenna attached with the phase shifter and the power divider on the back side of the antenna was designed and fabricated to install wing of UAV for compactness. The maximum gain is 0.1 dBi. Therefore, we obtained a basic antenna technology for compensating beam error according to wing deformation of an UAV installed array antennas.

• Journal of Navigation and Port Research
• /
• v.31 no.5 s.121
• /
• pp.415-420
• /
• 2007

In this paper, we have designed and fabricated a new type of bandpass-filter that used rectangular ring and interdigital capacitive feeding-structure. The filter is applied the modified rectangular ring and interdigital capacitive feeding-structure in patch, which reduce rho size of filter and IEEE 802. 11 correspond to wireless LAN domain(2.45GHz and 5.2GHz) for operating. As a result, the design and fabrication process of the filter become simple and the size of it is reduced more than 60% compared with RF filter are available conventional PEMBF(Parallel Edge-coupled Microstrip Bandpass Filter) of accounted circuit by minimum stage, measurement result of fabricated filter, center frequence is down 2.408GHz and 5.075GHz. input return loss is -39.169dB at 2.408GHz, -40.922dB at 5.075GHz. insertion loss is -0.437dB at 2.408GHz, -1.669dB at 5.075GHz.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.14 no.5
• /
• pp.513-520
• /
• 2003

In this paper, a novel design concept of frequency doubler using feedforward technique and DGS microstrip line is proposed. The feedforward loop plays a role of fundamental frequency suppression and DGS microstrip line suppresses over the 3rd order harmonic components. By using this new concept, the high suppression for the undesired signals could be achieved easily. The proposed technique is experimentally demonstrated in 1.87 GHz-to-3.74 GHz frequency doubler. The output power of -3 dBm at the frequency of 3.74 GHz(2f$\_$0/) is measured with 42.9 dB suppression of the fundamental frequency signal(f$\_$0/), 20.2 dB suppression of the 3rd harmonic signal(3f$\_$0/) and B9.7 dB suppression of the 4th harmonic signal(4f$\_$0/). The conversion loss of -2.34 dB ∼ -5.8 dB at the bandwidth of 100 MHz, the phase noise of -97.51 dB/Hz(＠10 kHz) were measured.