Bent Monopole Antenna Research Articles

Design of Controlled Radiation Pattern Antenna Using Bent Monopole Antenna Array for Anti-Jamming Application

Design of Controlled Radiation Pattern Antenna Using Bent Monopole Antenna Array for Anti-Jamming Application

A Simple Frequency- and Polarization-Reconfigurable Bent Monopole Antenna Based on Liquid Metal

In this letter, a frequency- and polarization-reconfigurable bent monopole antenna using liquid metal is proposed. The proposed antenna is designed to operate at continuously tunable frequencies and switch between left-handed circular polarization (LHCP) and right-handed circular polarization (RHCP) states. The frequency reconfigurability is achieved by controlling the length of the liquid metal to change the electrical length of the antenna. The circularly polarization can be achieved by injecting from the inlet, and excited by orthogonal horizontal radiation as well as vertical radiation. 3 dB axial ratio bandwidth of 37.5%(3.12–4.63 GHz) in LHCP state and 48.8% (3.07–5.05 GHz) in RHCP state can be achieved. The whole antenna is characterized by continuous tunability, reconfigurable frequency and polarization, and wide tunable bandwidth. The measured results of constructed prototypes are in close agreement with the simulation results, and its feasibility is fully proved.

Machine Learning Technique to Improve an Impedance Matching Characteristic of a Bent Monopole Antenna

We designed the wire monopole antenna bent at three points by applying a machine learning technique to achieve a good impedance matching characteristic. After performing the deep neural network (DNN)-based training, we validated our machine learning model by evaluating mean squared error and R-squared score. Considering the mean squared error of about zero and R-squared score of about one, the performance prediction by the resulting machine learning model showed a high accuracy compared with that by the numerical electromagnetic simulation. Finally, we interpreted the operating principle of the antennas with a good impedance matching characteristic by analyzing equivalent circuits corresponding to their structures. The accomplished works in this research provide us with the possibility to use the machine learning technique in the antenna design.

A miniature tri-band RFID reader antenna with high gain for portable devices

This paper presents a miniature monopole reader antenna for tri-band radio frequency identification (RFID) portable devices. The proposed antenna operates at the main RFID frequencies and can alleviate and compensate for the shortcomings of a single-band antenna. An additional rectangular stub couples with the bent monopole antenna, allowing the latter to resonate at the RFID bands at 902–928 MHz, 2.4–2.48 GHz, and 5.725–5.875 GHz. By bending the feedline, the dimensions of the miniature antenna are reduced to 115.5 × 20 × 1.6 mm3, facilitating its integration into portable devices. The measured bandwidths(return loss < −10 dB) of the proposed antenna are 677, 580, and 250 MHz in the three operating bands, 883–1560 MHz, 2.31–2.89 GHz, and 5.65–5.9 GHz, respectively, with high-gain characteristics. An experimental study of a fabricated prototype of the optimized antenna is performed, and the results verify its good performance.

무인항공기에 장착된 UHF 모노폴 안테나의 최적 위치 및 형상

본 논문에는 무인항공기에 장착된 UHF 안테나의 최적 위치 및 형상이 다양한 위치에서 EM 시뮬레이션을 통하여 분석되어져 있다. EM 시뮬레이션을 위하여 FEKO를 이용하였다. 시뮬레이션의 복잡도를 줄이고 분석시간과 메모리 이용도를 최소화 하기 위하여 비행체의 복합체 구조를 레이돔 구조를 제외하고 PEC 모델로 간략화 하였다. 시뮬레이션은 무인항공기의 날개와 Ventral Fin 위치에서 수행되어 졌고, 안테나 형상은 모노폴, 다이폴, 굴곡형 모노폴 안테나들을 이용하였다. 모노폴 안테나가 비행체 날개에 장착될 경우, 오른쪽 날개와 왼쪽 날개에 각각 장착되어지기 위하여 두 개의 안테나가 필요하고, 이 두 개의 안테나들은 가시선 데이터링크 지상 안테나에 대한 무인항공기 날개 방향에 따라 전환되어져야 한다. 모노폴 안테나가 Ventral Fin에 장착될 경우, 가시선 데이터링크 지상 안테나에 대한 무인항공기 날개 방향에 상관없이 하나의 안테나로 운용 가능하다. 또한, 안테나 이득도 비행체에 의한 Blockage 감소로 개선되어진다. 안테나 이득은 굴곡형 모노폴 안테나를 이용하여 더욱 더 개선되어 진다. 결론적으로 무인항공기에 장착된 UHF 안테나의 최적 위치 및 형상은 굴곡형 모노폴 안테나를 Ventral Fin 아래에 장착하는 것이다.

DUAL-LAYER EBG STRUCTURES FOR LOW-PROFILE ``BENT'' MONOPOLE ANTENNAS

We propose in this paper the design, realization and experimental characterization of a low-proflle metamaterial \bent monopole antenna with a total height of 0.027‚0 and a fractional bandwidth of 24.4% around 1.3GHz. The metamaterial (MTM) structure is a dual-layer mushroom-like electromagnetic band gap (DL- EBG) conceived and optimized to improve the antenna's operating bandwidth. Moreover, a \Sabre-Type antenna composed by two identical \bent monopole metamaterial antennas placed on both sides of a composite thin slab material has been simulated and realized. The \sabre antenna provides a vertically polarization and omnidirectional radiation patterns in the elevation plane while its radiation patterns are almost directional in the azimuth plane. A maximum gain of 8.7dB is obtained by measurement at 1.45GHz. A remarkable agreement is obtained between the measured and the simulated results.

Stub‐loaded bent monopole antenna with independent frequency tuning capability for compact wireless USB dongles

AbstractIn this article, compact monopole antenna with independent resonant frequency tuning capability is proposed.The antenna radiating patch consists of a simple, bent monopole element and an open stub. The bent monopole acts as a main radiator in 2.5 GHz band, whereas the open stub serves in 5.5 GHz band. A prototype of the proposed antenna was fabricated, and the reflection and radiation characteristics were measured to validate the antenna performances. Measured impedance bandwidths (VSWR < 2) exhibits dual‐broadband resonances, which are 2.08–3.02 GHz (lower band) and 5.13–6.15 GHz (upper band), corresponding to 36.9 and 18.1%, respectively. Therefore, VSWR bandwidth of the proposed design covers not only the WiBro, WiMAX, Bluetooth, 2.4 GHz WLAN, S‐DMB, but also the 5.2/5.8 GHz WLAN services. The peak gain was 5.76 dBi. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2548–2552, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27159