Earticle

본 논문은 X-Band 애플리케이션에 활용하기 위한 4x4 마이크로스트립 어레이 안테나 최적화 설계와 제작에 대한 연구 결과를 제시하고 있다. 일반적으로 마이크로스트립 패치와 어레이 안테나 설계 파라미터는 기판의 종류와 패치의 사이즈를 조정함으로써 원하는 공진 주파수와 이득을 얻을 수 있다. 이 연구는 X-Band 공진 특성과 이득을 향상시키기 위해 최적의 기판 재료로 설계된 4x4 어레이 안테나 설계와 제작을 통한 특성 측정 결과를 소개하였다. 설계된 안테나의 크기는 10mm(W)x7.4mm(W)x0.79(H)mm 이다. 사용된 유전체 기판은 Rogers RO 4350B(εr=3.54)이며 안테나 급전 방식은 안테나의 사이즈를 줄이기 위해 인셋피드(Inset-fed) 방식이 적용되었다. 제안된 구조의 단일패치와 4x4 어레이 안테나는 설계 중심 주파수 10.3GHz에서 안정된 SWR(<1.5) 특성과 18.5dBi의 이득으로 예측되었다. 시뮬레이션 결과를 바탕으로 안테나가 제작되었고 측정 결과도 시뮬레이션 결과와 유사한 특성을 나타내는 것을 보았다. 본 연구에서 제안된 안테나는 군사, 위성 통신, 생물의학 분야를 포함한 X-Band 애플리케이션에 활용될 수 있다.

This paper details research on the optimized design and fabrication of a 4x4 microstrip array antenna intended for X-Band applications. The study focuses on achieving the desired resonance frequency and gain by modifying the microstrip patch and array antenna parameters, including substrate type and patch size. It presents results from designing and fabricating a 4x4 array antenna with optimum substrate materials to enhance X-Band resonance characteristics and gain. The antenna dimensions are 10mm(W)x7.4mm(L)x 0.79mm(H), with an Rogers RO 4350B dielectric substrate (εr=3.54) and an inset-fed feeding method to minimize antenna size. Both the single patch and 4x4 array antennas demonstrated stable SWR (<1.5) and a gain of 18.5dBi at the target frequency of 10.3GHz in simulations. The fabricated antenna showed performance consistent with simulation results. This antenna design is suitable for X-Band applications, including military, satellite communications, and biomedical fields.

We designed Stepped Impedance Resonator (SIR) bandstop filter (SIRBSF) with hairpin coupling structures which has good performance and it is compact in size and great advantage having an excellent bandstop property. The center frequency of SIRBSF is 5.1 GHz which is the harmonic of the 2.55GHz band. The 3dB band width of the design is 200MHz with the insertion loss (S21) of 35 dB. The application is used for domestic and international fixed and mobile satellite and mobile communication. The overall size is (10 x 20) mm2.

In this paper, a microstrip bandstop filter (BSF) is designed and simulated for X-band wireless communication system. It consists of open stubs (parallel line with T-shaped) coupled with high impedance of stepped impedance resonator (SIR) at 7.5 GHz for X-band system applications. All the stubs are optimized to have the stopband characteristics. The layout pattern is simulated using Sonnet EM tool on Teflon substrate with a dielectric constant of 2.54 and thickness of 0.54 mm. The main features of this work are smaller size, low cost, and controllable bandwidth. The bandwidth can be controlled by adjusting the parallel line open stubs connected with open T-stub. The 3dB bandwidth is achieved as 0.3 GHz at 7.5 GHz with good frequency responses. The overall physical dimension of the designed BSF is 23.62 mm by 8.0 mm excluding reference lines.

In this paper, a symmetric microstrip meander spurline bandstop filter (SMMBF) is designed and simulated for X-band applications. The designed bandstop filter has a bandstop characteristic with higher insertion loss. The operating resonance frequencies of the bandstop filter is 9.2 GHz with insertion loss of less than 28 dB and return losses are below 1 dB. The miniaturized resonator filters consist of symmetric meander spurline with inductive and capacitive characteristics. The capacitive loaded spurline resonator filter provides a band rejection frequency response. The quality factor (Q) of the resonators filter is good for implementing in microwave oscillators too. Implementation of such resonator filter in MMIC technology is also possible due to their inherent capability to integrate into small sizes.

In this paper, a wideband balun of tapered structure using planar microstrip is desigde ad analyzed. The balun structure was fabricated on a Teflon substrate with a thickness of 0.8mm and relative dielectric constant of 2.5. Two back-to back CPW-to-CPS transitions were simulated and optimized using HFSS. A movel plaar balun using tapered structure of microstip to CPW is suggested and designed. The measurement result, the bandwidth for a reflection coefficient better than -10dB of the balun is 2GHz to 8GHz. The planar balun can improved the performance of wide band spiral antenna.

In this paper, microstrip stepped-impedance hairpin resonator (SIR) lowpass filter f.PF) by surface rnicromachining on GaAs substrate is sugsested. This filter has the advantages of compact side, easy fabrication, and sharp cutoff frequency response. The new SIR LPF shows the 3 dB passband of dc to 33 GHz, the insertion loss of 0.82 dB, and the return loss of better than 17 dB up to 25.57 GHz. This filter is useful for many microwave system applications.

본 논문에서는 비행체 탑재용으로 안테나의 소영화를 위해 GPS용 적층형 폴디드 마이크로스트립 패치 안테나를 제안하였다. 기존의 소형화된 마이크로스트립 패치 안테나는 고비유전율의 유전체를 이용한 소형화로 유전체 손실에 의해 대역폭이 작아지고 효율저하가 발생하게 된다. 제안된 안테나는 기존의 단점을 보완하는 소형화를 위해 먼저 Rogers사 TMM 10i(비유전율=9.8, 손실탄젠트=0.002) 유전체를 이용하였고, 다음으로 perturbation 효과를 적용시킨 방사소자를 유전체 표면에 폴디드 구조로 구현하였다. 이렇게 GPS L1대역에서 설계된 안테나의 방사소자 크기는 20.3 mm × 19.93 mm를 가지며, 기본 반파장 마이크로스트립 패치 원편파 안테나보다 94.2% 소형화 특성을 얻었다. 또한 –10 dB 대역폭의 경우 32.3 MHz(2.05%), 3 dB 축비 대역폭의 경우 6.7 MHz(0.43%)로 측정되었다. 방사패턴 측정 결과 최대이득은 x축 편파에서 0.56 dBi, y축 편파에서 1.23 dBi을 얻었다.

In this paper, microstrip antenna using multi-layer and folded structure for GPS application is presented for aircraft loading. Existing microstrip patch antenna used dielectric of high specific inductive capacity to miniaturize that cause smaller bandwidth and decline of efficiency due to dielectric loss. To compensate the existing flaws, Rogers TMM 10i(dielectric constant=9.8, loss tangent=0.002) is used for multi-layer dielectric miniaturization, and we construct folded radiating element on the surface of the dielectric applying perturbation effect. The antenna is designed in the bandwidth of GPS L1 band, and the size of the antenna's radiating element is 20.3 mm × 19.93 mm, and it gets 94.2% miniaturized characteristic of basic λ/2 microstrip patch antenna. Also the measured -10 dB bandwidth is 32.3 MHz(2.05%), 3 dB axial ratio bandwidth is 6.7 MHz(0.43%). Measured radiation patterns was maximum gain of 0.56 dBi at x axis polarization, 1.23 dBi at y axis polarization.