B. T. P. Madhav

Enhancement of CPW-fed inverted L-shaped UWB antenna performance characteristics using partial substrate removal technique

For the exchange of high rate information, wide band antennas are needed and their usage increased tremendously now a days. One of the major challenges in the design of Wideband antenna is the design of a small size antenna while providing wide bandwidth, omni-directional radiation pattern and stable gain. The proposed antenna consists of a monopole patch loaded with truncated L-shaped strip. The ground is extended vertically towards the two sides of the single radiator to improve the bandwidth. The size of the proposed antenna is 25 × 25 × 1.6 mm3 and is prototyped on FR4 substrate whose permittivity is 4.4. The proposed antenna is providing wideband characteristics with suitable gain for wireless communication applications.

Cylindrical Structured Multiple-Input Multiple-Output Dielectric Resonator Antenna

This paper presents the design and analysis of cylindrical shaped dielectric resonator MIMO antenna. The designed antenna was excited using coplanar waveguide feeding with rectangular L-shaped slots placed on the ground plane. The antenna was characterized using ANSYS Electromagnetic Desktop 17.0 (HFSS). Compared to the conventional microstrip antennas, the proposed dielectric resonator antenna has several advantages such as smaller dimension, high gain, and good radiation characteristics which are more suitable for millimeter wave range applications. The proposed antenna has better radiation characteristics with a peak gain of 9.08 dB, efficiency toward radiation is 97%, return loss bandwidth is 2.3 GHz, and it also offers front-to-back ratio of 16.3 dB at resonating frequency 60 GHz.

Octagonal Shaped Frequency Reconfigurable Antenna for Wi-Fi and Wi-MAX Applications

In present day communication systems, reconfigurable antennas have attained much prominence due to the ease of shifting frequency bands without change in the original structure of the antenna. In this paper, a frequency band reconfigurable microstrip octagonal patch antenna has been simulated and analyzed with four switchable states consisting of four narrow bands. By simulating the antenna, four frequency bands are achieved 0.1–1.1, 2.2–3.4, 4.8–5.2, and 7.4–7.8 GHz with return loss s11 < −10 dB. The designed antenna has plain structure with size of 40 × 40 mm2. To achieve switching, we used PIN diodes which are placed at the slotted structure on the ground plane. The software HFSS is used for simulation. From results, it is evident that there is a change in reconfigurability of the antenna with the change in positions of internal switches. The change in antenna parameters like return loss, directivity, and gain characteristics is evident.

A Frequency Reconfigurable Spiral F-Shaped Antenna for Multiple Mobile Applications

As the applications of mobile phones are increasing drastically, the need for small physical structures and low volume of antenna with less weight are appreciated. To meet the multiple frequency operations, reconfigurable antennas are suggestible candidates. A reconfigurable antenna is an antenna in which whole volume can be operated at different bands, which results the physical size of the multiband antenna can be reduced. The property of reconfigurability is attained in this paper by combining a Planar Inverted F antenna with a spiral structure appended with diodes. A significant improvement in gain is observed by switching different diodes on the antenna structure and shift in frequency bands is noticed. The simulation study with Ansys HFSS made the task simple to virtualize the antenna performance characteristics before the practical design with PIN diodes. The analysis of designed antenna is clearly analyzed with diode positions and switching operation.

Multiband Semicircular Planar Monopole Antenna with Spiral Artificial Magnetic Conductor

An umbrella-shaped planar microstrip patch antenna with defective ground is designed in this paper. The conventional ground of the antenna is replaced by the suitable artificial magnetic conductor (AMC) structures, which is in a defective ground. The AMC structures are the metamaterials which help in reduction of surface waves. The antenna structures are implemented to achieve multiband properties. A spiral artificial magnetic conductor (SAMC) with one arm and four arms is used as ground plane to improve antenna performance. Characteristics like operating bandwidth, antenna gain, and efficiency were analyzed for the proposed antennas. All the proposed antennas operate at frequencies 1.9, 7.3, 17.8, and 25 GHz. The average gain and radiation efficiency are improved by adding rectangular patches in the spiral SAMC ground. The detailed design of the proposed antennas and simulated results obtained using ANSYS HFSS are presented.

Arc-Shaped Monopole Liquid-Crystal Polymer Antenna for Triple-Band Applications

An arc-shaped compact monopole antenna with defected ground structure is designed for triple-band applications with gain enhancement are observed in this chapter. The antenna structures are implemented to achieve triple-band properties. By using linear array technique, characteristics like operating bandwidth, antenna gain, and efficiency were analyzed and improved for the designed antennas. The designed antenna has better radiation characteristics with a peak gain of 8.49 dB, efficiency toward radiation is 97%, return loss bandwidth is 2.3, 3.4, 5.2 GHz and it also offers front-to-back ratio of 4.1257. The average gain and radiation efficiency is improved by applying linear array to the proposed antenna. The detailed design of the proposed antenna is simulated using ANSYS HFSS 17.

Dual-Band-Notched CPW-Fed Antennas with WiMAX/WLAN Rejection for UWB Communication

A coplanar waveguide (CPW) fed ultra-wideband (UWB) antenna is designed to operate with dual-band-notched characteristics. In this work, different iterations are proposed with respect to the radiating element structure. The designed antenna models consist of a 50 Ω coplanar waveguide transmission line and different orientations of radiating elements. Single-band and dual-band characteristics of the notch are achieved for WiMAX/WLAN applications with the placement of split-ring resonators on the radiating patch element. The designed models are initially simulated with Ansys HFSS tool, later, validation of prototype model is performed for measuring results.

Design and Analysis of Circular Notch Band DGS Monopole Antenna

A configuration of circular notch band monopole antenna with DGS structure is demonstrated in the present article. The proposed MSP antenna is feed by microstrip line feeding with circular radiating element on top side of FR4 substrate and defected ground structure on the lower side. The basic circular monopole antenna is initially designed to operate in the wideband (2.5–12 GHz) and the modified proposed antenna is oriented to operate as notch band antenna (7.5–8 GHz). In order to attain single notch band characteristics, square shape slots in the ground plane are used. Better gain characteristics of 4.9 dB are realized by placing defected ground structure in the antenna model.

Design and Analysis of Compact Circular Half-Ring Monopole Antenna with DGS

A compact circular monopole shaped antenna is designed to operate at the dual band, and it is modified as half circle strip loaded circular monopole antenna with defected ground structure (DGS). The proposed antenna consisting of the combination of circular radiating element and half circle strip on the top side of the FR4 substrate material with permittivity 4.4. The bottom side a dumbbell-shaped DGS is incorporated to enhance the antenna bandwidth parameter. The proposed antenna is providing a bandwidth of 8 GHz and covering the UWB range. A peak realized a gain of more than 3 dB and directivity of 3.6 dB is achieved from the current design. The proposed antenna is providing excellent impedance and radiation characteristics in the operating band.