A low-profile wideband conical beam antenna which uses two concentric annular ring Slots in substrate integrated waveguide (SIW) technology is presented. First, a single ring antenna is considered and then the effect of introducing the second Slot on bandwidth is investigated and high bandwidth is achieved. A brief parametric study for different Slot width is presented. A prototype of the proposed antenna is fabricated and measured. The measured reflection coefficient is in good agreement with simulation. The theoretical result is also provided for S11 to validate the simulation and measurement results. The proposed antenna shows 30% bandwidth in 17 GHz center frequency (|S11<-10 dB). Radiation pattern was measured in three different frequencies in the entire frequency bandwidth. Maximum measured radiation efficiency is 93%. The antenna is very simple and low profile with a planar structure. Electrical dimensions are (1. 76𝜆 𝜆 0×1. 76𝜆 𝜆 0×0. 08𝜆 𝜆 0) with very simple feeding network which could be a suitable choice in many practical applications from anti-collision radars to WLAN applications.

The present study presents a novel microstrip line-feed compact square Slot Circular-Polarization (CP) antenna for Ku-band applications. The proposed square Slot antenna with circular trimmed corners was fabricated with the FR-4 substrate with the defected ground on the opposite side of the patch. The Axial Ratio Band-Width (ARBW) was considerably enhanced by adding a shorting pin and the Impedance Band-Width (IBW) was improved by etching the pentagon-shape Slot in the defected ground. The antenna oered the wide CP IBW of 4. 96 GHz (13. 6 GHz{18. 56 GHz), simulated ARBW of 4. 85 GHz (14. 51{19. 30 GHz), and positive gain in the Ku-band. The presented antenna is appropriate for Ku-band applications.

This paper presents the design, simulation, and measurement of two low-cost broadband circularly polarized (CP) printed antennas: a single element and an array at C band. The proposed single element antenna is excited by an L-shaped strip with a tapered end, located along the circular-Slot diagonal line in the back plane. From the array experimental results, the 3 dB axial ratio bandwidth can reach as large as 1900 MHz which covers the 4.7 GHz to 6.6 GHz frequency band. In addition, the measured impedance bandwidth for reflection coefficient of less than -10 dB has the bandwidth with the frequency range from 4.2 GHz to 8 GHz (C Band application). The CP element achieves a bandwidth of 16.6% for an axial ratio less than 3 dB. The proposed antenna array can provide a peak gain of about 8.7 dBic at 5.9 GHz. Acceptable agreements between the simulation and measured results validates the proposed design.

This paper presents a new approach for the design of a multiband uniplanar CPW-fed monopole antenna. The antenna consists of a fork like monopole strip to which is added an inverted U-shaped strip. The three branch fork like strip can create three resonant bands within the WLAN range while the placement of the inverted U-shaped strip provides a better impedance matching for the lowest resonant frequency band. Loading Slot on the top of the U-shaped strip with asymmetric arms can add two further resonant frequency bands. This antenna can cover the frequencies of PCS, WiMAX and WLAN applications along with the major part of the C band. A prototype of the antenna is fabricated and tested. A good agreement is found between simulated and measured results.

This paper presents the analysis of tapered Slot antenna by using the method of least squares (MLS). For this purpose first the conductor and dielectric regions are divided into suitable subsections. Then we assign the proper basis functions for their unknown currents. Therefore, the problem is changed to determining these currents: surface currents on conductor region and the polarization volume current in dielectric region of antenna. For solving the problem using MLS, we define the error function, which is based on a combination of two equations that satisfy the antenna electromagnetic conditions and then minimize it. So by computing these currents, we determine the far field radiation of the antenna. At the end of the paper, E-plane and H-plane patterns of several antennas and compare them with results of other papers that use the moment method.

A compact, high gain, series fed transverse Slot array antenna is designed on the top plate of a shorted corrugated H-plane horn. Corrugations are used to reduce the wavelength inside the shorted horn in order to suppress the grating lobe problem associated with the transvers Slot arrays. By etching eight transverse Slots separated by one guided wavelength, the array is formed and a proper broadside radiation is successfully achieved. The proposed structure can also be interpreted as a flat horn with directive radiation which is also more compact compared to the conventional H-plane horns as the guided wavelength inside it is reduced. The antenna is simulated by HFSS simulator and optimized for maximum gain and best matching condition. The simulation results show that the reflection coefficient is less than-10 dB around 15. 15 GHz with about 1. 3 % fractional bandwidth and the gain and SLL are about 19 dBi and-13 dB, respectively. Also, the cross polar discrimination of the antenna is better than 25 dB in both E-and H-planes. Simulation results were confirmed by comparing them with those obtained by CST software.

In this paper a new UWB textile Slot antenna has been designed with high precision. This work aimed to make closer steps towards real wearability by investigating the possibilities of designing wearable UWB antenna where textile materials are used for the substrate as well as the conducting parts of the designed antenna. The antenna is composed of three textile layers: the top and bottom are conducting layers and the third layer is a textile dielectric layer and sandwiched between these two conducting layers. The developed antenna offers flexible, light-weight and bendable properties, and can be easily incorporated into clothing using a simple iron-on adhesive process. The ironon process allows for the fabric to be washed without losing its adhesion. The antenna shows better than 13 dB return loss and peak gain 5±2 dB over FCC UWB from 3.1 to 10.6 GHz. The antenna’s overall size is 5mm´5mm.