An Experimental Investigation of the Effect of Flange Angle on Radiation Patterns of V-Slot Waveguide Antenna

Results of exhaustive study of the effect of metallic flanges on H-plane radiation characteristics of V-slot waveguide antenna are presented . It has been established that the beam can be sharpened or broadened by varying the flange angle . The adjustment of the flange angle and flange width would further improve the radiation pattern , yielding optimum efficiency from the flanged system

Axially Symmetric Radiation Patterns from Flanged E-Plane Sectoral Horn

A simple technique for obtaining identical E- and H-plane patterns from E-plane sectoral feed horn is presented. Halfpower beam width and gain of the antenna are also improved considerably. Experimental results for a number of horns with flanges of various parameters are also presented. This system may find practical application in radar and space communication systems

Axially Symmetric Radiation Patterns from Corrugated

A modified H-plane sectoral horn antenna with identical E- and'H- plane.patterns over the X-band frequency is discussed. This system has significantly reduced side lobes and hack lobes. Half=power beam width and gain of the antenna are also improved with enhanced matching , Experimental results for a number of horns with various flanges are presented . These find practical application for illuminating symmetric antennas like paraboloids and polarization measurements in radio astronomy, etc. Compared to the fixed pyramidal horns. the present system offers great convenience in trimming the antenna characteristics

Ultra-wideband slot antenna for wireless USB dongle applications

An ultra-wideband (UWB) printed slot antenna, suitable for integration with the printed circuit board (PCB) of a wireless universal serial-bus (WUSB) dongle is presented. The design comprises a near-rectangular slot fed by a coplanar waveguide printed on a PCB of width 20 mm. The proposed design has a large bandwidth covering the 3.1-10.6 GHz UWB band, unaffected by the ground length, and omnidirectional radiation patterns. A linear phase response throughout the band further confirms its suitability for high-speed wireless connectivity.

Compact dual-band antenna for wireless access point

A compact dual-band printed antenna covering the 2.4 GHz (2400-2485 MHz) and 5.2 GHz (5150-5350 MHz) WLAN bands is presented. The experimental analysis shows a 2:1 VSWR bandwidth of up to 32 and 8% for 2.4 and 5.2 GHz, respectively. The measured radiation patterns are nearly omnidirectional, with moderate gain in both the WLAN bands.

Analysis of a New Compact Microstrip Antenna

A new compact micro strip antenna element is analyzed. The analysis can accurately predict the resonant frequency, input impedance, and radiation patterns. The predicted results are compared with experimental results and excellent agreement is observed . These antenna elements are more suitable in applications where limited antenna real estate is available

Excitation of low-profile equilateral-triangular dielectric resonator antenna using a conducting conformal strip

A new configuration that employs a conducting conformal strip to excite the low-profile equilaterial-triangular dielectric resonator antenna (DRA) of very high permittivity is proposed. As compared with the previous aperture-coupling configuration, the new configuration has a wider impedance bandwidth (- 5.5%) and a higher front-to-back radiation ratio. The return loss, radiation patterns, and antenna gain are measured and discussed

A Compact Novel Slot-Loaded Dual-Frequency H-Shaped Antenna

A novel compact single-layer dual frequency microstrip antenna which uses an H-shaped geometry with two U-shaped slots embedded near the radiation edges, is presented. By changing the design parameters, the lower and higher resonant frequencies can be controlled easily, and a range of frequency ratios (1.716-2.363) can be obtained in this design. For the two operating frequencies of the proposed antenna, the same polarization planes and broadside radiation patterns are achieved. Compared to the regular dualfrequency patch antenna, this antenna can realize a significant size reduction

FDTD analysis of a symmetric T-strip fed wideband rectangular microstrip antenna

A theoretical analysis of a symmetric T-shaped rnicrostripfed rectangular microstrip antenna using the finite-difference titnedoniain (FDTD) method is presented in this paper. The resonant frequency, return loss, impedance bandwidth, and radiation patterns are predicted and are in good agreement with the measured results

A compact pentagonal monopole antenna for portable UWB systems

Design of a compact microstrip-fed ultra-wideband antenna suitable for USB dongle and other such space constraint applications is presented. The structure consists of a pentagonal monopole element and a modified ground plane that gives an impedance bandwidth from 2.8 to 12 GHz. Radiation patterns are stable and omni-directional throughout the band with an average gain of 2.84 dBi. The antenna occupies only 11 × 30 mm2 on FR4 substrate with permittivity 4.4.

Design of a microstip fed step slot antenna for UWB communication

The design and performance of a stepped slot printed monopole antenna in the ultrawideband is presented in this article. Multiple resonances generated by the stepped slot geometry are matched in the ultrawideband using a modified microstrip feed. The impedance bandwidth (SWR < 2) of the antenna is from 3 to 11 GHz. Radiation patterns are stable and omnidirectional with appreciable gain throughout the band. Performance of the antenna is also analyzed in the time domain, which reveals good pulse handling capabilities. Compact geometry of the antenna allows easy commercial deployment.

Ultra-wideband slot antenna with band-notch characteristics for wireless USB dongle applications

A compact ultra-wideband (UWB) printed slot antenna is described, suitable for integration with the printed circuit board (PCB) of a wireless, universal, serial-bus dongle. The design comprises of a near-rectangular slot fed by a coplanar waveguide (CPW) printed on a PCB of size 20 × 30 mm2. It has a large bandwidth covering the 3.1–10.6 GHz UWB band, with omnidirectional radiation patterns. Further, a notched band centered at 5.45 GHz wireless local area network bands is obtained within the wide bandwidth by inserting a narrow slot inside the tuning stub. Details of the antenna design are described, and the experimental results of the constructed prototype are presented. The time domain studies on the antenna shows a linear phase response throughout the band except at the notched frequency. The transient analysis of the antenna indicates very little pulse distortion confirming its suitability for high speed wireless connectivity.

Strip-loaded hollow dielectric H-plane sectoral horn antennas for square radiation pattern

The radiation characteristics of a new type of hollow dielectric H-plane sectoral horn antenna are presented. Metallic strips of optimum length are loaded on the H-walls of the sectoral horns. The effects of strip loading for producing square patterns in the H plane are discussed.

Design and Development of re configurable compact cross patch antenna for switchable polarization

Antennas are necessary and vital components of communication and radar systems, but sometimes their inability to adjust to new operating scenarios can limit system performance. Reconfigurable antennas can adjust with changing system requirements or environmental conditions and provide additional levels of functionality that may result in wider instantaneous frequency bandwidths, more extensive scan volumes, and radiation patterns with more desirable side lobe distributions. Their agility and diversity created new horizons for different types of applications especially in cognitive radio, Multiple Input Multiple Output Systems, satellites and many other applications. Reconfigurable antennas satisfy the requirements for increased functionality, such as direction finding, beam steering, radar, control and command, within a confined volume. The intelligence associated with the reconfigurable antennas revolved around switching mechanisms utilized. In the present work, we have investigated frequency reconfigurable polarization diversity antennas using two methods: 1. By using low-loss, high-isolation switches such as PIN diode, the antenna can be structurally reconfigured to maintain the elements near their resonant dimensions for different frequency bands and/or polarization. 2. Secondly, the incorporation of variable capacitors or varactors, to overcome many problems faced in using switches and their biasing. The performances of these designs have been studied using standard simulation tools used in industry/academia and they have been experimentally verified. Antenna design guidelines are also deduced by accounting the resonances. One of the major contributions of the thesis lies in the analysis of the designed antennas using FDTD based numerical computation to validate their performance.

A compact CPW fed slot antenna for ultra wide band applications

A printed compact coplanar waveguide fed triangular slot antenna for ultra wide band (UWB) communication systems is presented. The antenna comprises of a triangular slot loaded ground plane with a T shaped strip radiator to enhance the bandwidth and radiation. This compact antenna has a dimension of 26mm×26mm when printed on a substrate of dielectric constant 4.4 and thickness 1.6mm. Design equations are implemented and validated for different substrates. The pulse distortion is insignificant and is verified by the measured antenna performance with high signal fidelity and virtually steady group delay. The simulation and experiment reveal that the proposed antenna exhibits good impedance match, stable radiation patterns and constant gain and group delay over the entire operating band