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Neural network based estimation of resonant frequency and bandwidth of compact unilateral coplanar waveguide (CPW)‐fed flag shaped printed monopole antennas is presented. The proposed antennas are similar to CPW‐fed antenna; however, by replacing unilateral CPW feed instead of CPW feed, compactness of about 48.615 percent is achieved. These are designed on an inexpensive FR4‐epoxy substrate with dielectric constant of 4.4 and thickness of 1.6 mm. Resonant frequencies and bandwidths of the flag shaped antennas with different dimensions are computed using method of moment electromagnetic solver IE3D 15.10 and they have been given as training and test data for the proposed multilayered perceptron feed forward neural network with Levenberg–Marquardt training algorithm to estimate the resonant frequency and bandwidth of the proposed antennas. The estimated values of resonant frequency and bandwidth with average percentage of error are 1.275 and 0.325, respectively. For verification, the proposed antenna is fabricated and measured with resonant frequency 5.78 GHz and bandwidth of 1.0 GHz for HiperLAN/2 and IEEE802.11a applications. It has impedance bandwidth from 5.0 to 6.0 GHz for return loss lower than −10 dB and good omnidirectional radiation performance over entire frequency range, with a compact size of 11.07 × 27.5 × 1.6 mm3. Various features such as compactness, simple geometry, and low cost, uniplanar structure make the antennas suitable for modern wireless communication systems. This approach replaces the use of very complicated analysis. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:337–342, 2015

In this work, a Complementary Folded Triangle Split Ring Resonator (CFTSRR) loaded triband mobile handset planar antenna is presented. The proposed antenna consists of a dumbbellshaped radiating element and two CFTSRR metamaterial unit cells. The dumbbell-shaped radiating element resonates at 5 GHz. The presence of CFTSRRs additionally offers two lower band resonance. The CFTSRR-1 and CFTSRR-2 exhibit negative permittivity at 1.8 GHz and 2.4 GHz, respectively. The proposed antenna is designed to resonate at 1.8 GHz (GSM1800 MHz), 2.4 GHz, and 5 GHz (IEEE802.11ax) for voice and Wi-Fi applications of the mobile handset, respectively. The proposed antenna demonstrates compactness up to 88.6% at 1.8 GHz. The parametric studies are investigated to optimize the antenna in desired frequency bands by using Ansys HFSS19 software. The simulated and measured results are discussed. The measured result shows −10 dB reflection coefficient

In this paper, a rectangular monopole antenna engraved with a complementary split-ring resonator is proposed for dual-band operation. The proposed antenna is fabricated on an FR4 substrate with a dimension of 20 × 34 × 1.6 mm 3 . The entire simulation is done using CST EM studio software. The proposed antenna exhibits dual-band operation from 1.78 GHz to 1.90 GHz and from 3.45 GHz to 6.58 GHz. The band from 1.78 GHz to 1.90 GHz is due to the inclusion of CSRR, and its corresponding bandwidth is 120 MHz. It is validated with the quasi-static analysis. The permittivity characteristics of the proposed CSRR are retrieved using the NRW method and presented. The resonant frequency of the band created by the CSRR is 1.83 GHz with −37.68 dB as its return loss values. The second wider band is due to the combination of the mode created by the CSRR along with the radiating patch from 3.45 GHz to 6.58 GHz with 3132 MHz which has dual resonances at 3.65 GHz and 5.59 GHz with return losses of −30.23 dB and −29.80 dB. The optimal values are chosen with the help of parametric analysis. The designed antenna is fabricated and measured. The measured results of return loss, gain, E-plane, and H-plane are compared with simulated ones, and they comply with each other. The dual-band operation, compact size, stable radiation pattern along with gain above 2.3 dBi in the whole resonating band make it suitable for the GSM and WLAN/WiMAX/5G Sub-6 GHz band (new radio band).

In this paper, a dual band high gain miniaturized cross shaped patch antenna is proposed for IEEE 802.11ax applications. The radiating patch size is 0.330λ 0 × 0.417λ 0 on a low cost Flame Retardant 4 substrate. A cross shaped radiating element is designed to cover the upper band of IEEE 802.11ax, and a four ring circular Complementary Split Ring Resonator (CSRR) is etched on the cross shaped radiating element to cover the lower band of IEEE802.11ax. Thus the dual bands of 802.11ax are achieved. In order to enhance the gain, 2 × 2 array hexagonal metamaterial unit cell is positioned behind the substrate. To extract the constitutive parameters of the circular CSRR, NRW (Nicolson-Ross-Wier) retrieval method is used. The measured maximum gain is approximately 6 dBi, 10 dBi for 2.4 GHz, 5 GHz, respectively. Parametric study on the geometrical dimensions is investigated using HFSS 15.0.

This article presents a planar monopole antenna with reduced radiation hazard toward human head using thin-wire mesh which is needed in smart phone (mobile) for less crowded 801.11ac (5 GHz Wi-Fi) applications. The antenna consists of a rectangular radiating element with a particular rectangular part being removed from it to increase the electrical length of the antenna for miniaturization. CPW-feed and radiating element are printed on the topside of the double sided PCB. Radiation hazards toward human head has been reduced using a metallic thinwire mesh in the backside of the PCB. Orientation of metallic thin wire mesh play a vital role. It has been placed in such a way to disturb the fringing field coupled toward head direction (positive X direction). The proposed antenna offers an impedance bandwidth of 1.47 GHz from 4.35 GHz to 5.82 GHz with resonant frequency 5.18 GHz when it printed on an FR4-epoxy substrate with dielectric constant (e r ) of 4.4. It is over all in dimension of 21.7 3 25.5 3 1.6 mm 3 . It has been designed and optimized using parametric study on the geometrical dimensions are investigated using electromagnetic simulation software HFSS 13.0 (High Frequency Structure Simulator).

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In this paper, a Substrate Integrated Waveguide (SIW) band pass filter loaded with a square Complementary Split Ring Resonator (CSRR) etched with Defected Ground Structure (DGS) is proposed. SIW is a promising candidate for the design and development of various microwave and millimeter wave components useful in communication systems. Due to the evanescent mode propagation and TE 10 mode of the cavity, dual band (5.57/7.84 GHz) filtering is achieved with a 3 dB fractional bandwidth (FBW) of 6.8% and 4.1%, respectively. The dual bands achieve a low insertion loss of 1.8 dB and 2 dB, respectively. Cursor head DGS improves the out of band rejection to a greater level. The configuration is investigated with its corresponding circuit and simulated using Computer Simulation Technology (CST) software. The prototype is fabricated using a Rogers substrate with ε r of 3.5 and tested. This prototype finds its application in C band satellite communication systems. The measured results are consistent with the simulated ones.