Dual-band Reconfigurable Antenna Research Articles

A Four Slot Dual Feed and Dual Band Reconfigurable Antenna for Fixed Satellite Service Applications

A dual feed and dual-band reconfigurable antenna is designed, analyzed, and prototyped in this work for fixed satellite service communication applications. The designed model occupies the compact dimension of 24X21X1.2 mm on FR4 substrate and provides an input impedance of 50 ohms at both ports. The proposed model offers additional circular polarization characteristics at both the resonating bands. The PIN diode-based switching conditions, and the frequency reconfigurability analysis in both simulation and measurement are almost match. The combination of dual-band resonance, frequency reconfigurable nature, and compact dimension makes this model an attractive candidate in the specified field with considerable gain (8.5 dB) and efficiency (80%).

Frequency reconfigurable key-shape antenna for LTE applications

ABSTRACT This paper presents a compact dual-band reconfigurable antenna. This antenna covers the Long-Term Evolution (LTE) bands 1.9 GHz, 2.4 GHz, and 3 GHz. The reconfigurability was achieved with two PIN-diodes which provided four switching states. Both frequency and radiation characteristics have consistent results. The antenna gain was evaluated at every switching state. Results from the simulation and measurements have good agreement.

A Compact, Passive Frequency-Hopping Harmonic Sensor Based on a Microfluidic Reconfigurable Dual-Band Antenna

We propose here a fully-passive wireless liquid sensor using a harmonic transponder, which comprises a dual-band microstrip antenna reconfigured by different types of liquids injected in a fluidic cavity. Different from traditional radio-frequency (RF) backscatter sensors, the proposed harmonic-transponder sensor (or harmonic sensor) receives frequency-hopped RF monotones and backscatters their second harmonics, with the peak frequency shifted by dielectric properties of liquid mixtures. This microstrip antenna has a hybrid-feed structure, of which an outer split-ring patch exhibits a narrow-band TM310 mode at the fundamental frequency ( ${f}_{0}$ ) and an inner elliptical patch displays a wideband resonance centered at the second-harmonic frequency ( $2{f}_{0}$ ), achieved with hybridization of TM $_{e110}$ and TM $_{o110}$ modes. In particular, the outer split-ring patch is loaded with a fluidic channel system to tune the resonance frequency of the TM $_{3}10$ mode ( ${f}_{0}$ ). We demonstrate that the type of liquid mixture filling in the fluidic cavity can be clearly perceived by reading the peak received signal strength indicator (RSSI) in the spectrum of second harmonics. Our results show the potential for deploying this passive wireless sensor in noisy environments that include clutters, multiple reflections, jamming, and crosstalks.

Realization of Dual-Band Pattern Diversity With a CRLH-TL-Inspired Reconfigurable Metamaterial

A reconfigurable dual-band antenna with pattern diversity is proposed. By switching the dispersion curve of a composite right-/left-handed transmission-line-inspired structure, the antenna is able to realize both a broadside pattern and an omnidirectional pattern in both the 2.4835–2.5 GHz industrial scientific medical band and the 3.4–3.5 GHz WiMAX band. Despite its complex reconfigurability, only one feeding port is used. A small dual-frequency separation ratio is reached, which makes the antenna suitable for low-frequency range wireless communication systems. A prototype is fabricated and the measured results agree well with the simulated ones.

Designing and Optimization of Frequency and Beam Steering Reconfigurable MPA Antenna

In this paper single band antenna is converted to dual band reconfigurable antenna. The converted antenna is reconfigurable in both dual band frequency agility (with central frequencies 912 MHz and 1102 MHz) and radiation pattern. The direction of the main lobe is being varied in both E and H planes with the change in the switches’ states. The Antenna’s re-configurability in frequency is obtained with the use of two copper tapes acting as switches between the four copper annealed patches which are embedded on FR4 substrate. There is no need to change the material or dimension of the antenna to turn it into reconfigurable but the antenna is showing the reconfigurable properties only by changing the internal structure of the antenna using the switches. The antenna is fed by coaxial cable which is connected with SMA connector. The dimension of the designed antenna is 100 mm × 100 mm × 33.4 mm. The reconfigured antenna is optimized to get maximum directivity 1.687 dBi in H Plane at angel 0owhen the area of substrate is 90 mm ×90mm and the area of patch is 43.2 mm × 43.2 mm. The CST MW studio is used for design of antenna and simulating the results. The structure and dimensions of the antenna’s components paly important role in antenna design and improving the antennas’ parameters the future work is recommended to use diode switches in place of copper tapes to make an antenna reconfigurable.

Electrically Small Dual-Band Reconfigurable Complementary Split-Ring Resonator (CSRR)-Loaded Eighth-Mode Substrate Integrated Waveguide (EMSIW) Antenna

In this paper, we propose a novel electrically small dual-band reconfigurable antenna. By using a compact eighth-mode substrate integrated waveguide (EMSIW) structure, we designed a compact antenna. This antenna is capable of dual-band operation by additionally loading an electrically small complementary split-ring resonator (CSRR) structure. The EMSIW and CSRR structures are designed for satisfactory operations at bandwidths of 1.575 GHz [global positioning system (GPS)] and 2.4 GHz [wireless local area network (WLAN)], respectively. We load the CSRR with a varactor diode to achieve a narrow bandwidth and to enable the resonant frequency to continuously vary from 2.4 GHz to 2.5 GHz. Thus, we realize a channel selection function, which is used according to WLAN standards. Irrespective of the variation in the varactor diode voltage, the resonant frequency of the EMSIW is not varied, such that the antenna maintains a constant frequency at the GPS bandwidth even at different voltages. Consequently, as the DC bias voltage varies from 11.4 V to 30 V, the resonant frequency at the WLAN bandwidth continuously varies between 2.38 GHz and 2.5 GHz. We observe that the simulated and measured s-parameter values and radiation patterns are in good agreement with each other.

An Efficient Approach for Optimizing Frequency Reconfigurable Pixel Antennas Using Genetic Algorithms

In this paper we describe a method for optimizing frequency reconfigurable pixel antennas. The method utilizes a multi-objective function that is efficiently computed by using only one full electromagnetic simulation in the entire genetic algorithm optimization process. Minimization of the number of switches in the design is also attempted. The method is demonstrated using an antenna structure consisting of a rectangular grid of pixels adjacent to a ground plane and using RF MEMS switches for achieving the reconfigurability. The effects of the RF MEMS switches on the antenna performance as well as the control feed lines for them are also addressed. We provide both simulation and experimental results for a reconfigurable dual-band antenna that reconfigures the bands 820-1140 and 1720-1900 MHz to the bands 860-1160 and 1890-2300 MHz with dimensions of 39 mm × 24 mm on a ground plane of 40 mm × 65 mm with one switch only. The results demonstrate that reconfigurable antennas can be designed effectively with a minimum number of switches using an efficient optimization method.

이중 대역 주파수 가변 1/8차 소형 기판집적형 도파관 안테나

새로운 주파수 가변 이중 대역 안테나를 제안한다. 기존의 기판집적형 도파관(SIW: Substrate-Integrated Waveguide)에 비하여 1/8 크기를 갖는, 전기적으로 작은 1/8차 기판집적형 도파관(EMSIW: Eighth-Mode Substrate-Integrated Waveguide) 공진기 구조를 이용하여 전기적으로 작은 크기의 안테나를 설계하였다. 설계한 EMSIW 안테나 표면에 상보적 분할 링 공진기(CSRR: Complementary Split Ring Resonator) 구조를 추가적으로 탑재하여 이중 대역에서 동작할 수 있게 하였다. EMSIW와 CSRR 구조는 각각 1.575 GHz(GPS), 2.4 GHz 대역(WLAN) 주파수 대역을 만족시킬 수 있어 이중 공진 특성을 만족하였다. 기본적으로 CSRR은 대역폭이 좁기 때문에 Varactor 다이오드를 탑재시켜 주파수를 2.4 GHz에서 2.5 GHz까지 연속적으로 가변할 수 있게 하였다. 그에 따라 WLAN 표준에서 사용하고 있는 채널 선택 기능 또한 구현할 수 있다. Varactor 다이오드에 따라 EMSIW의 공진은 독립적으로 고정되어 GPS 주파수 수신을 안정적으로 유지할 수 있도록 설계하였다. 결과적으로 DC 바이어스 전압을 11.4 V에서 30 V로 변경함에 따라 GPS 대역 주파수는 고정되어 있고, WLAN 대역의 공진 주파수가 2.38 GHz에서 2.5 GHz까지 연속적으로 변화한다. 시뮬레이션, 측정값 사이에 반사 손실, 방사 패턴 특성이 잘 일치함을 관찰할 수 있었다. In this paper, we propose a new frequency reconfigurable dual-band antenna. By using an electronically compact eighth-mode substrate-integrated-waveguide(EMSIW) resonator, we have designed a compact antenna, which performs dual-band movement by additionally loading a complementary split ring resonator(CSRR) structure. The EMSIW and CSRR structures are designed to satisfy the bandwidths of 1.575 GHz(GPS) and 2.4 GHz(WLAN), respectively. We load the CSRR with a varactor diode to allow a narrow bandwidth and to enable the resonance frequency to continuously vary from 2.4 GHz to 2.5 GHz. Thus, we realize a channel selection function that is used in the WLAN standards. Irrespective of how a varactor diode moves, the EMSIW independently resonates so that the antenna maintains a fixed frequency of the GPS bandwidth even at different voltages. Consequently, as the DC bias voltage changes from 11.4 V to 30 V, the resonance frequency of the WLAN bandwidth continuously changes between 2.38 GHz and 2.5 GHz, when the DC bias voltage changes from 11.4 V to 30 V. We observe that the simulated and the measured S-parameter values and radiation patterns are in good agreement with each other.

Dual-band reconfigurable antenna for base-station applications

A novel reconfigurable antenna for dual-band operation is proposed. This antenna is composed of two square patches for lower frequency (patch 1) and upper frequency (patch 2), patch 2 being embedded in the centre cavity of patch 1. Frequency control can be realised using a switching circuit placed in the backside of the radiators without any switching components and capacitor variable components such as varactors, thus the proposed antenna can overcome the structural fragility of general reconfigurable antennas and operate in wideband with high gain characteristic (23% bandwidth with 8.4 dBi gain for band 1 and 12.1% with 9.0 dBi for band 2). Using the electrical and structural characteristics, the proposed antenna can be applied in base-station antennas providing multiple communication services.

MEMS based reconfigurable dual band antenna

AbstractIn this study, a novel MEMS technology based reconfigurable dual band monopole antenna implementing RF‐MEMS switch is proposed for satellite communications applications. The prototyped Dual band antenna is designed, fabricated, and tested. The proposed antenna is fabricated on Quartz and high receptivity silicon (HRS) using an ideal MEMS switch. The antenna structure consists of two elements—one element couples weakly to other element in OFF state while in ON state it couples strongly. This electromagnetic coupling, through a MEMS switch, gives rise to reconfigurable dual band antenna. The measured VSWR < 2 at 3.7–4.2 GHz frequency band when the switch is OFF, while in the ON state's VSWR < 2 at 5.9–6.4 GHz frequency band. The measured VSWR and radiation patterns indicate the suitability of this antenna for satellite applications. The fabricated switch exhibits an isolation of more than 40 dB while its insertion loss is <0.3 dB in the frequency range of interest. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1570–1575, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23426

Reconfigurable dual-band antenna with high frequency ratio (1.6:1) using MEMS switches

A reconfigurable patch antenna integrated by using RF-mircoelectromechanical system (MEMS) switches is presented. The proposed antenna radiates a right-hand circularly polarised wave at the selected dual frequencies (4.8 and 7.6 GHz) with a high frequency ratio (1.6:1). The switches are incorporated into the diagonally fed square patch for controlling the operation frequencies. The proposed antenna satisfies the 3 dB axial ratio criterion and has gain between 5–6 dBi at both operating frequencies.

Dual‐band reconfigurable antenna for wireless communications

AbstractA novel planar‐reconfigurable dipole antenna on ungrounded dielectric slab with parasitic reflector which has dual‐band and steerable endfire pattern characteristics, is proposed. A prototype is fabricated and both simulated and measured results validate the advantages of this antenna. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 40: 503–505, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20016