Dual-wideband Antenna Research Articles

Dual-Wideband Antenna with Dual Polarization and Enhanced Front-to-Back Ratio for High-Speed Communication Applications

The proposed antenna introduces a dual-wideband, dual-polarization design, employing Y-shaped bowtie radiators strategically positioned on both sides of an FR-4 substrate. This configuration aims to achieve polarization diversity, a crucial aspect in enhancing the performance and efficiency of wireless networks. To achieve this, improvements were made in radiation characteristics, particularly the front-to-back ratio (FBR), through the incorporation of a ring reflector and director. This led to an impressive average FBR enhancement of 7.38 dB at the lower band (LB), and 4.94 dB at the upper band (UB), respectively. Furthermore, the reflector and director height in relation to the radiator was meticulously adjusted to achieve a low-profile structure of dimensions 0.340λ0 × 0.340λ0 × 0.126λ0 (at 0.698 GHz). The antenna features both horizontally and vertically positioned radiators, each fed by two ports. It demonstrates an extensive overlapping impedance bandwidth (IBW) (S11 < -10dB) of 0.68-0.99 GHz (37.8%), and 1.62-2.99 GHz (61.9%) in the LB and UB for both radiators, with port isolation exceeding 18 dB. Alongside dual polarization and an enhanced FBR, the radiator exhibits a gain beyond 4.8 dBi and a radiation efficiency better than 70%, making it an exceptional choice for applications requiring high-speed wireless communication.

A dual wide-band ingestible antenna design for wireless capsule endoscopy

In this paper, we present a dual wide-band ingestible antenna design for wireless capsule endoscopy (WCE) biotelemetry applications. The design process employs Characteristic Mode Analysis (CMA) and driven modal analysis. The effectiveness of the prototype antenna is afterward assessed through measurements using a tissue-equivalent phantom liquid model. We investigate the effects of antenna implantation depth and capsule shell thickness on its performance, providing insights into practical considerations. The proposed dual-band antenna demonstrates good performance in both the 1.4 GHz Wireless Medical Telemetry Services (WMTS) and 2.45 GHz Industrial, Scientific, and Medical (ISM) bands, exhibiting measured impedance bandwidths of 36% and 22%, respectively. The measured peak realized gains are −22.9 dBi and −25.3 dBi for the WMTS and ISM bands, respectively, with a compact footprint of 78.5 mm2. To ensure health and safety and optimal performance, we evaluate the antenna's specific absorption rate (SAR) and link margin (LM). Additionally, we assess the performance of the proposed antenna in comparison with the state-of-the-art design for capsule antennas in WCE applications.

A Dual-Wideband Cavity-Backed Antenna by Using Waveguide Transition and Short-Ended Groove Loading

A novel scheme is presented to control the frequency response on an open-ended waveguide antenna. A groove is loaded in the waveguide that is used to independently control the frequency response of the antenna without affecting the radiation pattern, and a transition is used to provide additional control. A dual-wideband antenna is taken as an example to verify the effectiveness of the scheme. To demonstrate the idea, an antenna element and its <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2\times2$ </tex-math></inline-formula> array were designed, fabricated, and measured. Reasonable agreement between the measured and simulated results has been observed. The measured 10 dB impedance bandwidths of the lower and upper bands of the proposed element are achieved to be more than 22.2% and 14.2%, respectively, fully covering the 26/28 GHz band (24.25–29.5 GHz) and 39 GHz (37–40 GHz) band.

Modal Analysis, Inverse-Design, and Experimental Validation of Bandwidth-Controllable Suspended Patch Antennas Loaded With Cylindrical Anisotropic Impedance Surfaces

In this article, bandwidth-controllable suspended patch antennas (SPAs) loaded by anisotropic impedance surfaces (AISs) are proposed. A highly efficient yet accurate semianalytical modal expansion method (MEM) is developed for calculating the input impedance and radiation properties of the proposed antenna, which greatly reduces the simulation time and consumed memory compared to a commercial full-wave solver. The MEM is further utilized by coupling it with a genetic algorithm for effectively performing inverse-design, i.e., optimizing AIS-loaded SPAs with different predefined frequency responses. Three proof-of-concept antenna examples are designed, fabricated, and characterized, including an ultrawideband (UWB) antenna, a dual-wideband antenna, and a band-notched UWB antenna. The operating principle is illustrated by investigating the resonant modes of the AIS-loaded SPAs. The measured results of the three antennas exhibit good agreement with theoretical predictions, demonstrating that all three antennas have vertically polarized conical patterns in the E-plane and omnidirectional patterns in the H-plane with a cross polarization of smaller than −15 dB in their respective operational frequency band(s). The good performance demonstrates that the proposed AIS-loaded SPAs are promising candidates for broadband and multiband communications.

A simple dual wideband antenna for indoor application

In this article, a simple dual wideband antenna with a novel feeding structure is designed based on two folded dipoles. Because of the particular antenna structure, the feeding structure of the antenna works as an impedance transformer. Then, four resonance modes are excited to achieve dual wideband performance, which brings a wide impedance bandwidth to the two pairs of dipoles. A prototype of the proposed antenna is fabricated and measured. Results show that the proposed antenna successfully supports the dual wideband operation of 1.4–2.7 GHz (63%) and 3.4–5.2 GHz (41%).

Dual-Band Antenna With Large Beam Steering Angle Incorporating Endfire and Frequency Scanning Modes Using Double-Layer SSPPs Structure

A dual wideband antenna with a large beam steering angle through endfire radiation and frequency scanning radiation in each band is proposed for the first time. The antenna utilizes a double-layer (D-L) spoof surface plasmon polaritons (SSPPs) structure which exhibits stronger field confinement and lower cutoff frequency than the single-layer (S-L) SSPPs structure. The modulated D-L SSPPs structure can excite the space harmonic distributing in the fast-wave region and retains transmission in the slow-wave region. By combing the modulated D-L SSPPs waveguide and the Vivaldi radiator, both the slow-wave radiation (endfire mode) and the fast-wave radiation (frequency scanning mode) can be aroused in the two operating bands. An example antenna is designed and fabricated. In the slow-wave range from 3 to 9 GHz, the antenna works in the endfire mode with the beam direction of 90° and the realized gain varying from 3.55 to 8.24 dBi. Within the fast waveband from 13 to 34 GHz, the antenna operates in the frequency-scanning mode, accomplishing beam scanning from −90° to ±42.5° with the realized gain of 9.45–15.67 dBi. Thus, the proposed dual-band antenna can achieve two operating bands and two radiation modes, which offers a 180° beam-changing angle in total.

Dual wideband and high gain microstrip antenna for wireless system

In this paper dual wideband high gain circular shaped microstrip antenna with modified ground plane is presented for wireless communication systems. The overall dimension of the proposed antenna is 50 x 40 x 1.6 mm3. The radiating element consists of circular shaped patch which is excited by microstrip feed-line printed on FR4 epoxy substrate. The ground plane is on the other side of the substrate having a rectangular ring shape to enhance the peak gain of the antenna. The proposed antenna exhibits two wide fractional bandwidths (based on ? -10 dB) of 61.1% (ranging from 2.0 to 3.8 GHz, centred at 2.88 GHz) and 53.37% (ranging from 5.48 to 9.6 GHz, centred at 7.44 GHz). The measured peak gain achieved is 8.25 dBi at 8.76 GHz. The measured impedance bandwidth and gain suffice all the commercial bands of wireless systems such as 4G LTE band-40, Bluetooth, Wi-Fi, WLAN, WiMAX, C-band, and Xband. The measured results are experimentally tested and verified with simulated results. A reasonable agreement is found between them.

A Dual-Wideband Structure-Shared Antenna With Self-Diplexing Property for High-Power Microwave Application

This communication proposes a dual-wideband antenna that is composed of a shared structure with self-diplexing capability. The antenna structure is a combination of a tapered slot antenna (TSA) operating in the range of S- to X-bands and a horn antenna array that operates in Ka-band. The structure-shared antenna has high design freedom for each band with controllable properties for a dual-wideband application. The back-lobe level is greatly reduced at both bands due to the implementation of shared structure. The isolation between two ports is enhanced without additional decoupling structures that develops the self-diplexing characteristic of the antenna. Moreover, the electric field distributions of the proposed antenna are analyzed through simulation, which proves its potential in high-power microwave (HPM) application.

A miniaturized frequency reconfigurable antenna with half-mode CRLH-embedded metamaterial arm

Metamaterial properties of a novel half-mode CRLH unit cell are investigated and hence a compact dual-wideband antenna is designed using an array of four unit cells. The negative refraction of the metamaterial cell is utilized to miniature the antenna. A via-free open stub, in combination with an interdigital capacitor, makes the half-mode CRLH unit cell. The proposed antenna operates at both C-band (6.2–6.8 GHz) and X-band (8.5–9.2 GHz). The dual-wideband antenna is enabled with frequency reconfigurability by incorporating RF PIN diode in its ground plane in the next design step. The ON–OFF conditions of the PIN diode electrically switch the antenna into dual-band and single-band modes, respectively. In OFF state of the diode, the antenna behaves as a monopole and operates in single-band mode resonating at C-band (5.9–6.5 GHz) only. The measured results of the fabricated sample are in good agreement with the simulated ones.

A Design of Dual-Wideband Planar Printed Antenna for Circular Polarization Diversity by Combining Slot and Monopole Modes

A novel dual-wideband antenna is designed for circular polarization (CP) diversity in this communication. It consists of a horseshoe-shaped slot, two $L$ -shaped radiators, and two ports. The working principle of the horseshoe-shaped slot is half-wavelength slot mode, and the working principle of the $L$ -shaped radiator is quarter-wavelength monopole mode. The slot mode is applied to produce two lower CP resonant frequencies of two bands and the monopole mode are used to generate two upper CP resonant frequencies of two bands. By narrowing these two modes of two bands, a dual-wideband CP antenna can be designed easily. When port 1 is excited and port 2 is matched, this antenna radiates left-hand CP wave at lower band and right-hand CP wave at upper band at the $+ \textit {z}$ -direction. When exchanging the excited and matched ports, the radiation is reversed. The measured impedance bandwidths ( $S_{11} dB) are 113% (0.7–2.52 GHz) and 60.2% (3.47–6.46 GHz). The measured 3 dB axial ratio bandwidths are 72.5% (1.17–2.5 GHz) and 56% (3.52–6.26 GHz). The isolation between the two ports is better than 15 dB.

Design of a dual-wideband monopole antenna by artificial bee colony algorithm for UMTS, WLAN, and WiMAX applications

In this study, a dual-wideband monopole antenna has been designed and developed for the universal mobile telecommunications system (UMTS), wireless local area network (WLAN), and worldwide interoperability for microwave access (WiMAX) applications. A novel approach integrating artificial bee colony (ABC) with the HyperLynx® 3D electromagnetic platform based on the method of moments has been employed to calculate the design parameters of the monopole antenna performance for the respective target frequencies and return loss. The proposed dual-wideband antenna operates in the dual-frequency ranges of 1.69–3.99 and 4.75–6.22 GHz applicable for the UMTS, WLAN, and WiMAX applications and it is fabricated on the flame resistant-4 substrate plate of 42 × 51 × 1.6 mm3. The performance of the presented monopole antenna is analyzed in terms of gain, radiation pattern, and s-parameter. The input reflection coefficient (S11) parameter and radiation pattern of the antenna are verified through the measurements. The measured values of the antenna parameters are found to match well within tolerable limits with the simulation results. The results illustrate that the presented dual-wideband monopole antenna obtained by using the ABC algorithm exhibits better performance in point of operating bands and s-parameter as compared with the multi-band antennas previously published in the literature.

Dual‐wideband microstrip antenna for LTE indoor base stations

In this Letter, a dual-wideband microstrip antenna for long-term evolution (LTE) applications is proposed. The antenna is fed by a single port, and designed to operate at 800-960 MHz and 1700-2700 MHz simultaneously. The antenna has a return loss of less than -14 dB for both frequency bands, and gain of 3-4 dBi at the lower band and 6-8 dBi at the higher band. The proposed antenna may find its applications in second generation (2G), 3G, 4G LTE and WiFi systems.

A compact uniplanar antenna for nine-band LTE/WWAN operation in tablet computers

A compact uniplanar dual wideband antenna for tablet computers is presented. The proposed antenna provides full coverage of LTE700/2300/2500, GSM850/900/1800/1900, UMTS2100, Bluetooth, and 2.4-GHz WLAN bands with a very small foot print 30 × 10 mm2. The antenna has uniplanar structure and is easy to fabricate on single side of 0.8-mm thick FR4 substrate. This is achieved through three optimized strips: a feeding strip, an inductively coupled inverted L-shaped strip, and a shorted strip embedded with SMT components. The proposed design supports more than eight operating bands in 3:1 VSWR standard, exhibiting positive gains over all nine bands of operation and 80%–90% radiation efficiency in the higher LTE and WWAN bands. © 2016 Wiley Periodicals, Inc. Int J RF and Microwave CAE 26:496–502, 2016.

Small Wideband Monopole Antenna With a Distributed Inductive Strip for LTE/GSM/UMTS

We present a small, planar, and dual-wideband antenna for handheld devices, which consists of a driven spiral monopole and a distributed inductive strip designed. A dual-wideband characteristic is realized by using a coupling feed, a distributed inductor, and a folded strip, which excite multiple resonant modes to achieve wide impedance matching. The antenna size is reduced by spiraling of the monopole and meandering and folding of the distributed inductive strip, which occupies $20 \times 15~\hbox{mm}^{2}$ . The measured antenna gains and efficiencies are over 0.75 to 1.80 dBi and 60 to 82%, respectively. Radiation patterns are approximately omnidirectional in the x-y (H) planes for all bands: the LTE800, GSM850/900, GSM1800/1900, UMTS, and LTE2300/2500 bands.

Dual Wideband Antenna for WLAN/WiMAX and Satellite System Applications Based on a Metamaterial Transmission Line

A dual band planar antenna based on metamaterial transmission lines is presented for WLAN, WiMAX, and satellite system communication applications. This antenna is composed of an interdigital capacitor and a ground plane with triangular shaped slots on its top edges to broaden the impedance bandwidth. The measured bandwidth for 10 dB return loss is from 3.29 to 4.27 GHz and 5.04 to 9.8 GHz, covering the 5.2/5.8 GHz WLAN, 3.5/5.5 GHz WiMAX bands, and the X-band satellite communication systems at 7.4 GHz. The proposed antenna exhibits stable monopole-like radiation patterns and enough gains across the dual operating bands.

Design of Compact Dual-Wideband Antenna With Assembled Monopoles

A coplanar waveguide (CPW)-fed dual-wideband antenna formed by a triangular monopole and a U-shaped monopole is presented. The antenna can generate two wide bands centered at about 2.5 GHz and 5 GHz to cover all the 2.4/5.2/5.8 GHz WLAN bands and the 2.5/3.5/5.5 WiMAX bands. Furthermore, the antenna has a simple planar structure and occupies a small size of about 28 X 33 mm2, including the finite ground CPW feeding mechanism. Good dipole-like radiation characteristics over the operating bands are obtained.

Compact dual‐wideband antenna for WLAN/WiMAX applications

AbstractA compact CPW‐fed dual‐wideband antenna formed by a rectangular ring monopole and a rectangular monopole is presented. The measured 10 dB bandwidths for return loss are achieved to be 46.3% (2.36–3.78 GHz) and 31.4% (5.1–7 GHz) in the lower and upper band, respectively, covering all the 2.4/5.2/5.8 GHz WLAN bands and the 2.5/3.5/5.5 GHz WiMAX bands. Further, the proposed antenna has a simple planar structure and occupies a small size of 28 × 36 mm2, including the finite ground CPW feeding mechanism. Good monopole‐like radiation characteristic are obtained over the operating bands. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1228–1231, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25156

A Novel Design of Dual-wideband CPW-fed Antenna for WLAN/WiMAX Applications

A novel design of a dual-wideband CPW-fed monopole antenna for WLAN/WiMAX bands operation is proposed in this paper. The antenna is capable of generating two separate resonant modes with good impedance matching conditions. Prototypes of the proposed antenna have been constructed and experimentally studied. Good agreements between the measured and simulated results are achieved. The results show that the impedance bandwidth of the proposed antenna can reach up to 2.34–2.56 GHz and 3.2–7.15 GHz for S 11 < −10 dB. Moreover, this novel monopole antenna exhibits a nearly omnidirectional radiation pattern in the H-plane and a dipole like radiation pattern in the E-plane.