Zeroth-order Resonant Antenna Research Articles

버섯 형태를 갖는 광대역 ENG 영차 공진 안테나

본 논문에서는 microstrip line에서 광대역 특성을 갖는 ENG(Epsilon Negative) ZOR(Zeroth-Order Resonant) 안테나를 설계, 제작, 측정 및 비교, 분석하였다. 제안된 안테나는 mushroom 구조를 이용하여 설계하였고, 영차 공진 단일 셀의 공진 주파수는 12 GHz이다. 안테나 크기는 <TEX>$7.65{\times}1.31{\times}2.37\;mm$</TEX>(or <TEX>$0.306{\times}0.053{\times}0.095\;{\lambda}_0$</TEX> at 9.2 GHz)이다. 설계 방법은 방사 손실을 고려한 전송 이론 모델링을 바탕으로 설계하였다. 정합을 위한 결합 커패시터를 사용해서 안테나 공진 주파수가 9.2 GHz로 낮아졌으며, 이 주파수에서 측정된 대역폭은 1,831 MHz(20.0%)이며, 최대 이득은 7.1 dBi이다. This Letter presents a wideband ENG(Epsilon Negative) ZOR(Zeroth-Order Resonant) antenna designed on a microstrip line. It has a mushroom structure and its size is only <TEX>$7.65{\times}1.31{\times}2.37\;mm$</TEX>(or <TEX>$0.306{\times}0.053{\times}0.095\;{\lambda}_0$</TEX> at 12 GHz) owing to zeroth-order resonance. The design procedures with closed form solutions are provided using transmission line theory considering radiation loss. The measured antenna bandwidth is about 20.0 % at 9.2 GHz and antenna gain is 7.1 dBi despite the compact size.

A compact multiband antenna based on CRLH‐TL ZOR for wireless mobile system

AbstractA compact multiband antenna using a composite right/left‐handed transmission line (CRLH‐TL) zeroth‐order resonator (ZOR) for global system for mobile communications (GSM900/1800/1900, 880‐960/1710‐1880/1850‐1990 MHz), wideband code division multiple access (WCDMA, 1920–2170 MHz), and wireless broadband (WiBro, 2.3–2.4 GHz) operations is presented. The proposed antenna having a total volume of 35 mm × 5 mm × 3 mm comprises a lower band ZOR antenna part and an upper band ZOR antenna part. The zeroth‐order resonant properties are described and analyzed using dispersion diagrams based on the CRLH‐TL ZOR theory and the full‐wave simulation. The radiation patterns are the same as the omnidirectional characteristics and the maximum gains are 1.64, 2.47, and 3.32 dBi at 0.92, 1.88, and 2.2 GHz, respectively. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2852–2855, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24799

Wideband one-unit-cell ENG zeroth-order resonant antenna

A wideband epsilon negative (ENG) zeroth-order resonant antenna designed on a microstrip line is presented. It has a mushroom structure and its size is only 0.040λ0×0.235λ0×0.073λ0 at 9.2 GHz owing to zeroth-order resonance. The design procedures with closed-form solutions are provided using transmission line theory. The measured (simulated) antenna bandwidth is about 20.0% (13.0%) and antenna gain is 7.1 dBi (7.2 dBi), at 9.2 GHz, despite the compact size.

Metamaterial-based compact zeroth-order resonant antenna

A metamaterial-based compact one-unit-cell antenna realised on a microstrip line is presented. The size of the proposed antenna is only 6×13.5 mm (or 0.05×0.13λ0) at 2.7 GHz owing to zeroth-order resonance. The design procedures with closed-form solutions are provided using transmission line theory considering radiation loss. The measured antenna bandwidth is 15 MHz and total gain is 1.22 dBi.

Miniaturised zeroth-order antenna on spiral slotted ground plane

Presented is a novel miniaturised zeroth-order resonator antenna on a spiral slotted ground plane. The zeroth resonance property enables the resonant frequency to be independent of the antenna dimension. In addition, the slot on the ground plane makes it feasible to further reduce the overall size. The spiral shape of the slot is properly designed in order not to degrade the radiation efficiency while minimising the antenna size. The proposed idea is explained in terms of circuit parameters and experimentally demonstrated at 2.3 GHz.

A Compact Multiband Antenna Based on DNG ZOR for Wireless Mobile System

A compact multiband antenna using a double-negative (DNG) zeroth-order resonator (ZOR) for global system for mobile communications (GSM850/1800/1900, 824894/17101880/18501990 MHz), wideband code division multiple access (WCDMA, 19202170 MHz), and wireless broadband (WiBro, 2.32.4 GHz) operations is presented. The proposed antenna having a total volume of 40 times 6 times 3 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> comprises a lower-band ZOR antenna part and an upper-band ZOR antenna part. The zeroth-order resonant properties are analyzed by magnitude and phase distributions of the surface magnetic field using near-field scanning system. The performance of the antenna is verified by experimental data obtained from fabrication and measurement. The antenna offers omnidirectional radiation patterns and measured radiation efficiencies exceeding about 53% and 41% for lower and upper bands, respectively.

확장된 대역폭을 갖는 소형 Epsilon Negative ZOR 안테나

본 논문에서는 확장된 대역폭을 갖는 소형 epsilon negative(ENG) zeroth-order resonance(ZOR) 안테나를 제안하였다. 대역폭을 유지하고 ENG ZOR 안테나의 면적을 줄이기 위해서 안테나 패치 위에 패턴을 새겼고 meandered via를 삽입함으로써 매우 큰 병렬 인덕턴스를 발생시켰다. 동일한 면적, 공진 주파수에서 동작하는 ENG ZOR 안테나에 직선 via 대신 meandered via를 삽입하게 되면 유효 유전율의 분포의 기울기가 공진 주파수 근방에서 더 낮아지고 따라서 대역폭은 넓어진다. 결과적으로 제안한 meandered via를 가진 ENG ZOR 안테나는 직선 via를 가진 나선 구조 ENG ZOR 안테나와 동일한 면적을 가짐에도 불구하고 1.38배의 대역폭을 가지고 있는 것을 확인하였다. 또한, meandered via를 가진 ENG ZOR 안테나는 일반적인 mushroom ZOR 안테나보다 64 %의 면적감소를 보였다. 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.

Magneto-Dielectric Material을 이용한 소형 Composite Right/Left-Handed Transmission Line Metamaterial 안테나

본 논문에서는 magneto-dielectric material을 이용하여 CRLH-TL 안테나를 소형화 시키는 방법을 제안하였다. 제안된 안테나는 patch와 via를 이용하여 구현한 mushroom 구조의 CRLH-TL 안테나에 SRR을 이용한 magneto-dielectric material을 장하한 구조이다. 시뮬레이션을 통해 SRR의 동작 특성을 살펴보았고, SRR을 이용하여 기판의 투자율 값을 증가시킬 수 있음을 확인하였다. 또한, magneto-dielectric material을 이용함으로써 CRLH-TL 안테나의 공진 주파수를 감소시킬 수 있음을 확인하였다. -1차 공진 모드에서 7.13 %, 0차 공진 모드에서 23.9 %의 주파수 감소 효과를 얻을 수 있었다. 0차 공진 모드에서 동작하는 안테나를 제작하여 반사 손실과 방사 패턴을 살펴보았다. 제작된 안테나의 동작 주파수는 1.888 GHz이며, 측정된 대역폭은 0.48 %이고, 이득은 0.534 dBi, 효율은 51.7 %이다. A CRLH-TL based compact metamaterial antenna on a magneto-dielectric material is proposed. The proposed antenna is composed of two patches and vias, which is loaded by a magneto-dielectric material constructed by SRRs. The characteristic of SRRs is studied, and the size reduction of the antenna by using the magneto-dielectric material is confirmed. The simulated resonant frequency of the antenna has showed a decrease of 7.13 % at - 1st-order resonant mode, and 23.9 % at zeroth-order resonant mode. A zeroth-order resonant antenna is fabricated and measured, which has a resonant frequency of 1.888 GHz, a bandwidth of 0.48 %, a gain of 0.534 dBi, and an efficiency of 51.7 %.

Epsilon Negative Zeroth-Order Resonator Antenna

It is confirmed that zeroth-order resonance appears in the epsilon negative (ENG) meta-structured transmission line (MTL) as well as in the conventional double negative (DNG) MTL. The zeroth-order resonant characteristics are described using dispersion relation of ENG MTL based on Bloch and Floquet theory. Appling the novel concept of the ENG zeroth-order resonator (ZOR), an ENG ZOR antenna is proposed. The radiation characteristics of the ZOR antennas using the DNG and ENG MTL are simulated and measured, and are proven to be the same.

Zeroth Order Resonance Loop Antenna

A new type of low-profile omnidirectional antenna is proposed in this paper. The proposed antenna has the conceptual configuration of the horizontal magnetic loop current on perfect electric conductor plane, which has been realized by the zeroth-order resonator (ZOR) antenna using mushroom structure. The mushroom structure as a transmission line has negative, zero, and positive propagation constant depending on its operation frequency since mushroom structure is artificial composite right-left handed transmission line. Zeroth-order resonance, of which frequency is independent of physical length, is naturally presented. In particular, mushroom ZOR antenna generates a uniform vertical electric field against ground plane, so that it omnidirectionally radiates in a horizontal plane. Operation frequency, absolute gain, and gain variations for omnidirectional radiation of the designed prototype are 7.9 GHz, 2.6dBi, less than 1.5 dBi, respectively