Search Results (10)

In this study, a metasurface-based reflectarray is designed for X-band applications. The unit cells are equipped with an H-shaped slotted patch for additional resonance and phase range. Linear phase variation by altering the length of the patch is realized with a range exceeding ${480}^{\circ }$. The reflectarray is designed and fabricated on a thin and high-quality Rogers 5880 substrate. The Finite Element Boundary Integral (FEBI) method is used to simulate a $23\times 23$ element reflectarray and then fabricated to achieve the measured results using an anechoic chamber. The peak gain of the proposed reflectarray is 25.5 dBi recorded with an aperture efficiency of 63.7% at a center frequency of 10 GHz. The cross-polarization and side-lobe levels in the entire band are less than −33 dB and −21 dB, respectively. Moreover, the proposed reflectarray antenna achieves a 20% 1-dB gain bandwidth. Full article

This paper introduces a novel single-layer microstrip patch element designed to achieve a wide beamwidth, in order to address the growing demand for wide-angle scanning capabilities in modern phased array systems. The proposed element, comprising a slot-etched circular patch and an array of metallized holes arranged in square rings, offers a unique approach to beam shaping. By carefully adjusting parameters such as the slot structure and feeding position, our element is engineered to simultaneously excite both the TM₀₁ and TM₂₁ modes, a key feature that contributes to its wide beamwidth characteristics. Through the constructive interference of these modes, our element demonstrates a remarkable 3 dB beamwidth of approximately 150° in both principal planes, showcasing its potential for wide-angle scanning applications. To validate the practical performance of this proposed element, two linear phased arrays are manufactured and experimentally evaluated. The simulation results confirm the wide-angle scanning capability of the antennas in both the E-plane and H-plane. Furthermore, the experimental assessment demonstrates that these linear phased arrays can effectively generate scanning beams within a frequency range of 25 GHz to 28 GHz, covering a wide angular range from −60° to 60°, while maintaining a gain loss within 3 dB. This innovative design approach not only offers a promising solution for achieving a wide beamwidth in microstrip patch elements, but also holds significant potential for the development of cost-effective phased arrays with wide-angle scanning capabilities, making it a valuable contribution to the advancement of phased array technology. Full article

This paper proposes an eight-element dual-band multiple-input multiple-output (MIMO) antenna that operates in the fifth generation (5G), n78 (3400–3600 MHz), and WLAN (5275–5850 MHz) bands to accommodate the usage scenarios of 5G mobile phones. The eight antenna elements are printed on two long frames, which significantly reduce the usage of the internal space of the mobile phone. Each antenna element is printed on both surfaces of one frame, which consists of a radiator on the internal surface and a defected ground plane on the outer surface. The radiator is a rectangular ring fed by a 50 Ω microstrip line which is printed on the top surface of the system board. A parasitic unit is printed on the outer surface of each frame, which is composed of an inverted H-shaped and four L-shaped patches. Each parasitic unit is connected to the internal surface of the frames through a via, and then it is connected to a 1.5 mm wide microstrip line on the top surface of the system board, which is connected to the ground plane on the bottom surface of the system board by a via. Four L-shaped slots, four rectangular slots, and four U-shaped slots are etched onto the system board, which provides good isolation between the antenna elements. Two merged rectangular rings are printed on the center of each frame, which improves the isolation further. The return loss is better than 6 dB, and the isolation between the units is better than 15 dB in the required working frequency bands. In addition, the use of a defected ground structure not only makes the antenna element obtain better isolation but also improves the overall working efficiency. The measurement results show that the proposed MIMO antenna structure can be an ideal solution for 5G and WLAN applications. Full article

A low-profile, wideband, and high-gain antenna array, based on a novel double-H-shaped slot microstrip patch radiating element and robust against high temperature variations, is proposed in this work. The antenna element was designed to operate in the frequency range between 12 GHz and 18.25 GHz, with a 41.3% fractional bandwidth (FBW) and an obtained peak gain equal to 10.2 dBi. The planar array, characterized by a feed network with a flexible 1 to 16 power divider, comprised 4 × 4 antenna elements and generated a pattern with a peak gain of 19.1 dBi at 15.5 GHz. An antenna array prototype was fabricated, and the measurements showed good agreement with the numerical simulations as the manufactured antenna operated in the range of 11.4–17 GHz, with a 39.4% FBW, and the peak gain at 15.5 GHz was 18.7 dBi. The high-temperature simulated and experimental results, performed in a temperature chamber, demonstrated that the array performance was stable in a wide temperature range, from −50 °C to 150 °C. Full article

This study proposes a patch antenna with an H-shaped slot with direct matching and harmonic tuning (rejection) functions for microwave power transfer. This antenna enables an integrated active antenna in which the power amplifier and antenna are directly connected without using a matching circuit for the fundamental frequency and harmonic rejection filter to improve the efficiency of the amplifier. The integrated design also reduces the total size of the amplifier and antenna, allowing for a higher-density array antenna. Characteristic mode analysis was performed to explain the working principle of the harmonic rejection function. The designed antenna at 5.8 GHz was fabricated to study its harmonic tuning function. The magnitude of the reflection coefficient of the proposed antenna was at a fundamental frequency of −40.4 dB for an amplification device with an optimum load impedance of 100 Ohm. At the second harmonic frequency, the magnitude and phase of the reflection coefficient at the second harmonic frequency were −0.79 dB and −177.6°, respectively; at the third harmonic frequency, they were −0.92 dB and −179.5°, respectively. Finally, the designed antenna was integrated into an amplifier circuit to verify that it achieved similar drain efficiency as when using the impedance tuner. It was confirmed that the harmonic rejection function of the proposed antenna increases the drain efficiency of the integrated power amplifier by 5.5%. The measurements revealed that this antenna is suitable for use in microwave power transfer because of its fundamental matching and harmonic-processing capabilities. Full article

The aim of this work is to propose a dual band millimeter wave (mmwave) MIMO antenna system for 5G technology. In addition, the arrangement of the antenna elements in an array should be in such a manner that without using the traditional decoupling structures and/or techniques, a reasonable isolation level must be achieved. To demonstrate this, a system consists of four radiating elements that are etched on a 0.508 mm-thick Rogers-5880 substrate. The dielectric constant of the substrate is 2.2 and the loss tangent is 0.0009. Each radiating element consists of three parts; an E-shaped patch, an H-shaped slot within a patch, and a transmission line. The system is resonating at two different mmwave frequencies, i.e., 28 GHz and 38 GHz with a minimum port isolation of 28 dB. The mean measured gain is found to be at 7.1 dBi at 28 GHz and 7.9 dBi at 38 GHz with average efficiency, and envelope correlation coefficient (ECC) of the system at 70%, and 0.0005 respectively. The proposed system is designed and simulated in a full-wave electromagnetic wave software Computer Simulation Technology (CST), fabricated using LPKF D104 milling machine, and measured using R&SZNA67 vector network analyzer. An excellent agreement is observed between the simulated and the measured results and a detailed comparison with the previous works is also presented. Due to attributes such as low-cost, easy to fabricate, and dual-band, it is believed that this system will find its application for future 5G systems. Full article

A new design approach for a mmWave high gain planar antenna is presented. The proposed method can increase antenna directivity with a minimally enlarged radiation patch while the operation frequency is still matched at a higher target frequency. The fundamental structure of the proposed antenna is configured by a H-shaped and slot-loaded patch with a shorting pin symmetrically located across a signal excitation port. Further, to match the operation frequency with the frequency for the highest achievable gain, a vertically stacked matching conductor was inserted along the signal feed path between the radiation patch and the ground layer. The proposed single antenna showed the simulated directivity of 9.46 dBi while the conventional patch with a same dielectric had 8.07 dBi. To verify practical performance, a 2 × 2 array antenna was fabricated at 28 GHz and showed the measured gain of 12.5 dBi including the array feed loss. Full article

The isolation between the microstrip patches has a great significance to examine the performance of the multiple-input-multiple-output (MIMO) antennas. The patch antennas are placed on the top of 1.46 mm thick Rogers RO3003 substrate having a length of 60 mm, a width of 50 mm, and relative permittivity of 3. The distance between the resonators is 0.06λ and they are stimulated by two coaxial probes extended from the bottom ground layer. The defective ground structure of the H-shape slot is inserted on the bottom ground layer to achieve high isolation (mutual coupling reduction). The proposed MIMO antenna operates at 5.3 GHz frequency, which can be used for WiMAX, Wi-Fi, and future 5G services all over the world. The results of the designed structure have been simulated in a finite element method-based solver high-frequency structure simulator (HFSS). The simulated results show that the reflection coefficient (S11) and isolation (S21) at the desired frequency are −32 dB and −41 dB, respectively. Full article

This paper presents a new compact microstrip filtering antenna with modified shaped slots to improve the impedance bandwidth. The proposed microstrip filtering antenna consists of three parts: the monopole radiating patch antenna; the Stepped Impedance Resonator (SIR) filter; and the feeding microstrip line. The designed structure is achieved on one-sided glass epoxy FR-4 substrate with dielectric constant ε_r = 4.4 and thickness h = 1.6 mm. The design procedure of the proposed filtering antenna starts from the second-order Chebyshev low pass filter (LPF) prototype. The achieved results show an excellent performance of S11-parameter with broadside antenna gain on +z-direction. Having two transmission zeros at 5.4 GHz and 7.7 GHz, good skirt selectivity and a wide-band impedance bandwidth of about 1.66 GHz makes the designed filtering antenna suitable for high-speed data communications. Both the simulation results generated by using the Computer Simulation Technology (CST) software package and the measurement achieved by using a vector network analyzer (HP 8510C) and the anechoic chamber show good agreement. Full article

A triple band-notched ultrawide band (UWB) antenna is presented to avoid the interference of services working in the UWB band, such as WLAN, WiMAX and X-band satellite systems. The arc H-shaped slot on the radiating patch creates a low frequency notched band, while the other two band-notched bands are formed by cutting narrow slots on the ground plane. The presented antenna can operate on the ultrawide band efficiently and inhibit interference from three different kinds of narrow band communication systems. The simulation and measurement results show that the antenna has excellent band-notched function on the rejectband and almost omnidirectional radiation pattern on the passband. Full article