Ultra-wideband Planar Monopole Antenna Research Articles

Dual Stopbands Ultra-Wideband Antenna with Defected Ground Structure

A novel compact ultra-wideband (UWB) microstrip-fed planar monopole antenna with dual band-notched characteristics is presented. By etching two simple U-shaped defected ground structure (DGS) with different length in the feedline, the dual stopbands can be obtained respectively. The expetimental results show that the proposed antenna achieved an impedance bandwidth of 3.1–10.6 GHz with VSWR < 2, except the bandwidths of 3.3–3.8 GHz for worldwide interoperability for microwave access (WiMAX) and 5.1–6.3 GHz for wireless local area network (WLAN) application. The fabricated antenna also shows the broadband impedance-matching, stable gain, good group delay and approximate omnidirectional radiation patterns across the major bandwidths.

Frequency Notched UWB Planar Monopole Antenna Optimization Using a Finite Element Method-Based Approach

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> The objective of this work is the design and optimization of an ultrawideband (UWB) planar monopole antenna with frequency-notched behavior intended to get rid of the 5–6 GHz frequency band for WLAN compatibility purposes. An optimized profile UWB planar monopole designed by means of a Simulated Annealing algorithm and full three-dimensional finite element method, detailed in a companion paper, was considered as the design starting point. In order to design the band-notched rejection no full finite element analysis is carried out on each profile modification as is usual. The procedure is based on a genetic algorithm and a multipurpose admittance matrix approach instead. Artificial ports are allowed in the computational domain and an admittance-type matrix comes up. As a result, a multiport network describes the electromagnetics within the analysis domain. Circuit manipulations of this network efficiently outperform full-wave analyses for different monopole modifications, thus making it possible to use this strategy in a computer aided-design scheme. </para>

Planar Ultrawideband Antennas With Multiple Notched Bands Based on Etched Slots on the Patch and/or Split Ring Resonators on the Feed Line

Three types of ultrawideband (UWB) antennas with triple notched bands are proposed and investigated for UWB communication applications. The proposed antennas consist of a planar circular patch monopole UWB antenna and multiple etched slots on the patch and/or split ring resonators (SRRs) coupled to the feed line. Good agreement is achieved between the simulated and measured results. These techniques are significant for designing UWB antennas with multiple narrow frequency notched bands or for designing multiband antennas.

Design of a Multiresonator Loaded Band-Rejected Ultrawideband Planar Monopole Antenna With Controllable Notched Bandwidth

We present a new multiresonator loaded band-rejected planar monopole antenna for ultrawideband applications. The proposed microstrip-fed antenna is composed of a flared metal plate, a truncated ground plane, and two pairs of folded strips. By applying the resonance nature of the folded strips and the associated cross coupling effects, the proposed antenna demonstrates bandstop-filter-like response with bandwidth controllability at the targeted rejection band. To illustrate the antenna operating mechanism more clearly, an equivalent circuit model consisting of RLC lumped resonators and J-inverters is discussed and extracted. The antenna input admittance calculated with the help of the equivalent circuit model agrees reasonably well with the simulated one obtained by the full-wave simulator. The design concept and the simulated and experimental results including the return losses, radiation patterns, and gain responses versus frequencies are carefully investigated throughout the paper. A parametric study in terms of the bandwidth tunability of the proposed design at the notched band is performed. The effects of the finite size ground plane are studied in this paper as well.

Development of Ultrawideband Antenna With Multiple Band-Notched Characteristics Using Half Mode Substrate Integrated Waveguide Cavity Technology

Investigations on planar ultrawideband (UWB) antenna with multiple band-notched characteristics based on half mode substrate integrated waveguide technology are presented. The proposed antenna consists of a planar UWB monopole antenna and a half mode substrate integrated waveguide cavity which can generate multiple stopbands by proper arrangement. Planar antennas with dual, triple and quadruple notched bands are designed and implemented. The notched frequencies and their bandwidths can be adjusted according to specification by altering the cavity and feed line independently. These antennas are fabricated with two-layer printed circuit board (PCB) process. Sharp and high band rejection, narrow frequency notches are achieved, which are in good agreement with the simulated results. This technique is suitable for designing wideband antenna with multiple frequency notches or for creating multiband antennas.

A Compact Band-Notched Planar Monopole Antenna from 3 to 24 GHz

A compact ultra-wideband (UWB) microstrip-fed planar monopole antenna with the band-notched characteristic is presented. This antenna comprises an annular-shape radiating element and a tuning stub which is inserted into the annular structure to obtain the band-notched characteristic. The notch frequency can be easily adjusted from 5 to 6.3 GHz by tuning the length of the stub. The VSWR characteristic from (3–24 GHz) and quasi omni-directional radiation pattern is observed. The proposed antenna is suitable for all UWB communication applications and prevents interference with the WLAN systems.

Novel Modified UWB Planar Monopole Antenna With Variable Frequency Band-Notch Function

A novel modified microstrip-fed ultrawideband (UWB) planar monopole antenna with variable frequency band-notch characteristic is presented. By inserting two slots in the both sides of microstrip feedline on the ground plane, much wider impedance bandwidth can be produced. A modified H-shaped conductor-backed plane with variable dimensions is used in order to generate the frequency band-stop performance and control its characteristics such as band-notch frequency and its bandwidth. The designed antenna has a small size of 22 x 22 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and operates over the frequency band between 3.1 and 14 GHz for VSWR < 2 while showing the band rejection performance in the frequency band of 5.1 to 5.9 GHz.

Study of Dual Stopbands UWB Antenna with U-slot and V-slot DGS

A peach-like ultra-wideband (UWB) planar monopole antenna (PMA) with dual stopband characteristic is presented in this paper. It is designed to work on a substrate Rogers RT5880 that has a thickness of 1 mm and relative permittivity of 2.65. The proposed antenna is fed by microstrip line; the U-slot is used to reject the frequency band (3.3–4.2 GHz) limited by IEEE 802.11a or HIPERLAN/2. Another rejection band (5.15–5.825 GHz) limited by IEEE 802.11b and C-band satellite communication systems is obtained by using the V-slot defected ground structure (DGS). The size of the antenna is 33 mm × 35 mm. Effects of varying the interior degree of the V-slot DGS and the length of the U-slot on antenna performance have also been studied. Measured result shows the designed antenna with an impedance bandwidth covering at least 3.11 to 15 GHz assuming a 10 dB return loss, except 5.04–6.42 GHz and 3.35–4.24 GHz band. Also the simulated results show that the antenna has omnidirectional radiation patterns in the x-z plane and good gain flatness.

Band-notched inverted-cone monopole antenna for compact UWB systems

A microstrip-fed planar ultra-wideband monopole antenna with band-notch characteristics is proposed. The antenna size is compact (18 30 mm) and operates over an extremely wide band of 3 16 GHz. The proposed design consists of an inverted cone as the radiating patch and a tapered ground plane. Wideband matching is obtained by properly shaping the ground. A pair of symmetrically placed quarter wave slot resonators is embedded in the ground plane for rejecting the 5 6 GHz WLAN band. Results indicate a stable and omnidirectional radiation pattern with an average gain of 3 dBi and a sharp reduction in gain at notched frequencies. Moreover, measured group delay and transmission characteristics show excellent transient response.

Novel Planar Monopole UWB Antenna with 5-GHz Band-Notched Characteristic

This paper presents a novel band-notched planar monopole antenna with a compact size of 25×20×1.6 mm3 for ultra-wideband (UWB) applications. The proposed antenna is composed of an asymmetric annular-ring patch and an stair-style ground plane. An inverted-T structure is employed to realize a band rejection. It is demonstrated to provide a wide bandwidth (VSWR<2) from 2.8 GHz to 11.6 GHz including a 5-GHz band-notched characteristic with satisfactory omni-directional radiation patterns. Good agreement has been obtained between the simulated and experimental results.

Active UWB antenna with tunable band-notched behaviour

An ultra-wideband (UWB) planar monopole antenna with a tunable band-notched response is proposed. Tuning of the rejected frequency is realised by loading an embedded resonant slot with a varactor. Simulations and measurements are presented for the proposed antenna, both in frequency and time domain.

Finite‐ground‐plane effects on the ultra‐wideband planar monopole antenna

AbstractImpedance and radiation characteristics of an ultra‐wideband (UWB) planar monopole antenna with a finite circular ground plane are experimentally studied. The significant effects of the ground‐plane size on the lower‐edge frequency of the antenna's impedance bandwidth are observed, and there exists an optimal diameter of the circular ground plane for achieving a maximum impedance bandwidth. Large ground‐plane effects on the radiation pattern and antenna gain are also seen, especially for the lower frequencies in the antenna's UWB impedance bandwidth. Details of the experimental results are presented and discussed. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 535–537, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20526