Compact Ultra-wideband Slot Antenna Research Articles

Compact UWB Slot Antenna With Dual‐Circular Polarization and Improvement of CP Performance

ABSTRACTThis study presents an ultrawideband (UWB) slot antenna with a dual‐circular (left‐ and right‐hand) circular polarization. The presented circularly polarized (CP) antenna involves 45° oriented patches cooperating with I‐ and L‐shaped stubs fed by a directional coupler. Using a directional coupler produces orthogonal electric fields to generate CP operation, and as a result of the cooperation between patches and stubs, antenna CP performance is improved. The fabricated antenna, including two microstrip ports, occupies an area of 50 × 50 × 1.016 mm3. By stimulating each antenna port independently, it is possible to obtain right‐hand circular polarization (RHCP) and left‐hand circular polarization (LHCP). The experiments show that the antenna being presented has an operating frequency of 116.14% (2.87–10.82 GHz) and an axial ratio bandwidth of 33.97% (7.11–10.02 GHz). Furthermore, a stable radiation pattern was also measured for the antenna, which had a maximum gain of 2.77 dBic in the operating frequency band.

Compact Ultra-Wideband Slot Antenna with Dual Band Rejection by Using H-Shape Notch

The main objective is to design a dual band rejection micro strip patch antenna. In this antenna, H-shaped slots are made in the patch to achieve notched characteristics at two licensed band employed for Wimax and WLAN band. The above mentioned frequency ranges are licensed for WLAN and satellite communication applications. These antennas maintain the Omni-directional radiation patterns and are mostly suited for ultra wide band applications. For wide band operation, the shape of patch has been altered to octagonal just by chamfering the corners of the rectangular patch. The antenna parameters like radiation patterns, VSWR, reflection loss have been described clearly in this section. Radar applications, terrestrial networking and communication, space communications are some of the applications in this ultra wide band frequency range.

Design of Compact Ultrawideband Slot Antenna With Improved Band-Edge Selectivity

A small ultrawideband (UWB) slot antenna is proposed using a stepped impedance resonator feeding line, aiming at improving band-edge selectivity. The proposed antenna mainly comprises a feeding line with low-pass characteristics at the top of the dielectric substrate and two slots at the bottom. The stepped impedance resonator is used to improve the upper band-edge selectivity, and the narrow slot near the stepped slot improves the lower band-edge selectivity. The frequency selection range, the frequency selective characteristic, and the reflected zeros of the antenna upper band-edge are analyzed and studied. The measured results show that the antenna covers the frequency range of UWB systems from 3.1 to 11 GHz (114%) with the reflection coefficient less than −10 dB. Compared with the traditional UWB antenna, the proposed compact antenna has advantages in size and band-edge selectivity and is more suitable for UWB applications. The ratio of the −3 dB bandwidth to the −10 dB bandwidth is 1.038, which is very close to 1.

Structure and EM‐driven design of novel compact UWB slot antenna

In this study, a structure and design optimisation procedure of a novel compact ultra-wideband (UWB) slot antenna has been presented. In order to achieve small size of the structure and maintain acceptable electrical performance, a sufficiently large number of geometry parameters have been introduced. These include a stepped-impedance feed line and a meandered slot with all of dimensions being parameterised and subject to optimisation. All parameters are simultaneously adjusted using automated electromagnetic (EM)-simulation-driven optimisation algorithm. The design process is oriented towards explicit size reduction of the antenna structure. Penalty function approach is utilised to control the reflection response. In order to reduce the computational cost of the optimisation process, variable-fidelity EM models are utilised. The footprint of the optimised antenna is only 8.93 × 17.9 mm (160 mm2) while maintaining reflection below the –10 dB threshold in the entire UWB frequency range. The antenna has been favourably compared with the state-of-the-art compact structures in terms of the size. The obtained numerical results are supported by measurements of the fabricated antenna prototype.

A compact UWB slot antenna optimized by genetic algorithm

AbstractA compact ultra‐wideband (UWB) slot antenna based on a mesh‐grid structure is designed. A genetic algorithm is used to optimize the mesh‐grid structure as well as other parameters of the proposed antenna for good impedance matching in the UWB band. The optimized UWB antenna has a compact size of 24 mm × 30 mm and is fabricated and measured. According to the measured results, the proposed antenna yields a wide bandwidth, defined by VSWR<2, ranging from 3.1 to 12.2 GHz and a nearly omnidirectional radiation pattern in the H‐plane. The antenna gains within the matching band are measured and a gain variation from 3.1 to 5.9 dBi is obtained. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26179

Design of a compact ultrawideband slot antenna with dual band-notched function

A compact ultrawideband (UWB) microstrip-fed slot antenna with dual band-notched function is presented.The prototype consists of an L-shaped microstrip line, a modified ground plane with T-shaped slot and a small stub embedded on the ground for impedance matching. The designed antenna satisfies the return loss requirement of larger than 10 dB in UWB frequency range from 3.1 to 10.6 GHz, whereas shows the wireless local area network and worldwide interoperability for microwave access band notched in the frequency band of 5.1–6 GHz and 3.5–4.1 GHz by the inserted rectangle strips. Detailed analysis and experimental results for the design are studied and investigated. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:245–249, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25739

Compact ultra-wideband slot antenna fed by coplanar waveguide and microstrip line with triple-band-notched frequency function

A compact ultra-wideband (UWB) printed slot antenna fed by coplanar waveguide (CPW) and microstrip line with multi-band-rejection characteristics is proposed. The small antenna fed by CPW and microstrip line has a volume of 40 × 22 × 0.8 × mm 3 . By adding an inverted U-shape slot on the tapered radiating patch, the antenna provides band-rejection characteristics. The centre frequencies of three notched bands at 2.4, 3.5 and 5.5 GHz can be adjusted by modifying the length of the inserted slot. Good agreement is achieved between the simulated and measured results. The measured impedance bandwidth of the proposed antenna ranges from 2 to 12 GHz for voltage standing wave ratio ≤ 2, excluding the rejection bands. The omni-directional radiation patterns of the fabricated antenna fed by CPW and microstrip line are presented, which show that the designed antenna is a good candidate for various UWB applications. The measured peak gain variation is less than 4 dB over the operating frequency band.

WITHDRAWN: A compact ultra-wideband slot antenna with dual band-notched characteristics

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Compact Ultra-Wideband Slot Antenna with Stepped Slots

In this paper, a compact ultra-wideband (UWB) slot antenna with two stepped slots is presented. The overall dimension of the antenna is as small as 15 × 25 × 0.8 mm3. The measured impedance bandwidth defined by voltage-standing wave ratios (VWSR) < 2 is from 3.1 to more than 11 GHz. The proposed antenna exhibits a nearly omni-directional radiation pattern, stable gain and constant group delay in the UWB band. Due to the advantages of compact size and simple structure, the proposed antenna is very suitable for various portable UWB systems.

Erratum: A compact ultrawideband slot antenna with multiple frequency bands

Abstract© 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1446, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23370

Compact Ultra-Wideband Slot Antenna with Dual Band-Notched Characteristics

A compact coplanar waveguide (CPW) fed monopole ultra-wideband antenna with dual band-notched characteristics is presented. Dual notched frequency bands are achieved by using a U-slot in the radiating patch and a L-slot defected grounded structure (DGS) in each side of the ground plane. Each stopband can be easily realized and debugged by adjusting the location and the length of the relevant slot without disturbing the other stopband. Experimental results demonstrate that the proposed antenna has a super-wideband from 2.5 to 12 GHz for voltage standing wave ratio (VSWR) less than 2, except two frequency stopbands of 3.3–4.2 GHz and 5.2–6 GHz.