In this paper, a wideband two-segmented four-element triangular dielectric resonator antenna (TDRA) with coaxial probe feed has been proposed. The proposed antenna has been analyzed, optimized, and studied through Ansoft HFSS simulation software. The prototype of the proposed antenna has been fabricated and its input characteristics are measured with the help of R&S Vector Network Analyzer. Good agreement has been obtained between simulated and measured results. The proposed design has been compared with two segments TDRA and found wider bandwidth with lower resonant frequency. The proposed antenna provides monopole-like radiation pattern over the entire bandwidth with nearly 33% bandwidth (return loss ≥10 dB) at a resonant frequency 6.9 GHz and 4.93 dBi peak gain. The proposed antenna is suitable for application of C-band microwave frequencies.

Fractals have unique properties such as self-similarity and space-filling. The use of fractal geometry in antenna design provides a good method for achieving the desired miniaturization, multi-band, and wideband properties. In this communication, novel fractal geometry is proposed based on which a multiband antenna is designed. The proposed antenna has fractal patches which are shaped as different iterations of an eight-pointed star. The multiband behavior is in the frequency range from 4.50 to 17.00 GHz. The proposed antenna is designed on a dielectric substrate Roggers RO4003 lossy with a dielectric constant of εr = 3.55. The antenna has applications in commercial and military communication system.

This paper presents the dual band notch characteristics of Ultra wideband (UWB) monopole antenna. Proposed antenna (30 × 30 mm2) consists of arrow shaped patch and truncated ground plane. Operating range of the proposed antenna (voltage standing wave ratio < 2) is 2.2–11 GHz. In order to achieve dual band stop characteristics, λ/2 open ended angularly separated slit pair has been inserted on the radiator for world interoperability for microwave access (WIMAX) (3.3–3.9 GHz) band rejection performance and wireless local area network (WLAN) (5.1–5.9 GHz) band rejection has been realized by introducing a pair of angularly separated λ/2 conductor backed plane (CBP). Using proper adjustment of angular separation for both slit pair and CBP pair, enhanced band rejection can be achieved for the WIMAX and WLAN band, respectively. The performance of antenna has been investigated in terms of frequency domain and time domain to assess its suitability in UWB communication.

Defected ground structure (DGS)-integrated arc-cornered rectangular microstrip antenna (RMA) has been investigated to achieve broadband along with high co-polarized to cross-polarized radiation (CP–XP) isolation over principal as well as over skew planes without affecting the dominant mode co-polarized (CP) radiation pattern. The present arc-cornered RMA on circular and rectangular dot-type DGS is thoroughly studied and compared with the conventional rectangular microstrip antenna. In the present paper, a crucial emphasis is given to improve CP–XP isolation in all the skew planes and by employing circular dot-type DGS around 20 dB CP–XP isolation is achieved over whole skew planes as well as in the H-plane with the proposed structure with 20% impedance bandwidth. On the contrary, the CP–XP isolation and impedance bandwidth vary in opposite manner in case of the rectangular dot-type DGS. Around 25 and 10 dB CP–XP isolation with 9 and 22% impedance bandwidth have been obtained with thin and thick rectangular dot-type DGS, respectively. The corners of the patch surface are rounded in such a way to reduce spurious radiations from the sharp corners, which are generally attributed for high XP radiation along the diagonal directions.

A novel dual-band planar antenna with a low profile for mobile communication system is proposed in this paper. The antenna is composed of one shorted patch with two radiating notches for low frequency resonance and one square patch for high frequency resonance. The low profile is achieved via the shorting patch, which introduces the parallel electrical field between the reflector and antenna. A step-impedance microstrip line is used to feed the antenna. The coupling between the square patch and microstrip line cancels out the inductance of shorting probe, which increases the working bandwidth of proposed antenna. A prototype with a low profile of 0.0286λ is fabricated and measured. The antenna achieves dual impedance bandwidths of 1.6% for the low frequency band and 60% for the high frequency band, covering the frequency range 851–865 MHz and 1.97–3.65 GHz, respectively. The measured results show good agreements with the simulated ones.

A design approach for printed planar slot array antennas is presented. The antenna array consists of half-wavelength slot radiators positioned on a rectangular grid, and a slotline feed network. Three planar slot array antennas for use in IEEE 802.11a applications are designed, a 2 × 2, a 2 × 4, and a 4 × 2 array, all radiating above an electric conductor ground plane placed a quarter-wavelength below the printed slots. These slot arrays have higher aperture efficiencies and occupy less space than typical microstrip patch arrays. The measured impedance bandwidths of the designed unidirectional slot arrays were 19.8, 15.3, and 16.7%, respectively, with peak gains of 11.7, 13.9, and 14.4 dBi. Measured results show very good agreement with the simulated results, which serves as validation of the array design procedure and the accuracy of the simulated results.

This paper presents a very fast and highly efficient full-wave hybrid method for analyzing an integrated dielectric lens antenna (ILA) fed by multilayered substrate-integrated waveguide (SIW) slot antenna/array. The feeding antenna structure is modeled as a stacked parallel-plate waveguide with metallic posts, coupling, and radiating slots. Physical optics method in conjunction with three-dimensional ray tracing technique is employed to analyze the effect of the dielectric lens on the SIW feeding slots. Fields in the SIW structure are computed by considering the Dyadic Green's function expressed as an expansion of vectorial cylindrical eigenfunctions and taking into account scattering at the conducting posts. Slots are modeled with equivalent magnetic currents expressed as a sum of domain basis functions. By imposing continuity of the tangential components of the fields an integral equation is obtained that is solved with the application of method-of-moments. In order to validate the proposed technique, a hemispherical ILA fed by a double-layered SIW cavity which is backed with slot antenna is analyzed. Excellent agreement is obtained with HFSS software together with significant improvement in computational time and memory requirements.

This paper presents an optimized ink-reducing meander dipole antenna structure suitable for implementing printed radio frequency identification (RFID) tags. The proposed antenna designs contain empty ink-reducing hollowed-out areas along the antenna's arms such that the resulting antennas require much less conductive ink to produce yet still achieve decent antenna performance compared with the conventional solid-arm dipole antennas. The simulation results demonstrate that when the ratio between the width of the hollowed-out areas and the width of the antenna arms is about 0.6, the resulting RFID tag experiences a slight read range performance degradation of <10%, while it offers a sizeable ink consumption reduction of almost 50%.