DGS based mutual coupling reduction between microstrip patch antenna arrays for WIMAX applications

In this paper, a new defected ground structure is using to miniaturize microstrip patch antenna array for S-band at 2.45GHz. Initially, the novel structure of microstrip patch antenna designed at C-band resonates at 5.8GHz which operate in the Industrial Scientific Medical band (ISM). The proposed DGS is integrated in the ground plane of the patch antenna for size reduction. This structure has all favor to obtain a great gain and size reduction of microstrip patch antenna array. Finally, the resonance frequency of the novel structure of microstrip patch antenna shifts from 5.8GHz to 2.45GHz and with better performance miniaturization up to 85.53%. The antenna array presents a good performance in terms of gain 7.026dB and bandwidth 157.5MHz in the Industrial Scientific Medical band (ISM) centered at 2.45GHz. The design and simulation process is carried out by using two electromagnetic solvers CST-MW studio and HFSS.

Novel electromagnetic band-gap (EBG) structure as a four arms spiral shape is presented to replace the conventional ground plane of MPA. MPA with different feed techniques (inset, offset and center line feed) are presented. The structure investigated and illustrated some merits to design multi-band EBG structure by adjusting the capacitance and changing the inductance through varying width and length of the spiral ground plane. Four arms spiral artificial magnetic conductor (SAMC) as a ground plane of microstrip patch antenna creates multi resonant frequencies, improves antenna gain and reduces antenna size compared to a conventional microstrip patch antenna element at same size. From investigation we obtained that four spiral arms ground plane with offset feed MPA and equal spiral width with air gap =0.017λ o gives 72% reduction of electrical antenna size with multi-resonating frequencies at GSM, Bluetooth, WLAN, and other wireless applications bands.

Summary form only given. A reconfigurable antenna based on liquid crystal technology is presented in this paper. It comprises of a 1×4 microstrip patch antenna array, LC-based inverted microstrip line (IMSL) phase shifters, and RF-feeding and biasing networks. Nematic LC (N-LC) cell is used as tunable substrates for both the microstrip patch antenna array and the phase shifters. The dielectric tensor of N-LC is controlled a DC or low-frequency AC bias voltage. The microstrip patches are used as waveguide radiating elements while the LC-based IMSL phase shifters are used to steer the main beam. The RF signal coupled between the phase shifters and microstrip patch antennas are guided and then radiated from the top face of the microstrip patch antennas. As a proof of concept, the beam steering capability of the reconfigurable antenna is demonstrated by steering the main beam to -27°, 0 and 27° at 14.5 GHz and the frequency tuning capability is demonstrated by changing the frequency from 15.9 GHz at 0V to 14.3 GHz at 10 V, a tuning range of 10%. Comparisons with measurements are provided in order to validate the proposed numerical approach and illustrate the potential use of LC's as tunable materials in microwave and millimeter-wave frequencies.

The 5G multiple-input multiple-output (MIMO) microstrip antenna with isolation enhancement that is tiny and based on a BandPass metamaterial (BPM) is presented in this study. The expectation of higher data rates drove the development of fifth-generation (5G) mobile communication networks. The performance of a two-element microstrip antenna array with and without bandpass metamaterial is compared in this work. The antenna consists of two parts, with its radiators positioned to report the parallel direction. The array antenna's overall dimensions are small, measuring 40 × 72 × 1.6 mm3. The proposed isolated double patch parallel antenna produces bandwidth and mutual coupling equal to 11GHz and less than -30dB at a frequency range from 1.5 to 6GHz, respectively, while the rectangular microstrip patch antenna array produces these values at 14.80 GHz and -55.94dB. When compared to the double microstrip parallel antenna, the double microstrip parallel antenna with BPM is superior in terms of mutual coupling. This increasing demand for faster data speeds in the rapidly changing field of mobile communication technologies is met by this creative antenna.

This work presents a wideband 60 GHz microstrip patch antenna (MPA) array based on low‐temperature co‐fired ceramic (LTCC) multilayer technology. Four parasitic patches are stacked above the driven MPA. An additional resonant mode is excited by the proposed parasitic surrounding stacked patches (PSSPs) to enhance the bandwidth of the MPA. The structure of the PSSPs increases the gain of the MPA due to its array configuration. The proposed PSSP structure can find many applications in designs for large‐scale antenna arrays because the PSSPs and the driven microstrip patch are distributed at different layers. This arrangement allows a direct feed network to the MPA without the blockage caused by the PSSPs. A 2 × 2 antenna array was designed and fabricated with the PSSPs to further increase its gain. The proposed array can achieve a gain of 10.5 dBi and a wide bandwidth of 27.3% at 60 GHz.

The microstrip patch antennas are associated with some disadvantages, such as narrow bandwidth and low gain. To meet the demands of long distance communication, is necessary to design antennas with very high gain. The easiest way of gain enhancement can be obtained is from the array models, but the increasing array spacing, the gain of the antenna gets reduced significantly also decreasing array spacing, a strong mutual coupling is appears. This letter describes a novel configuration of mushroom-type EBGs structures 13×2 to reduce mutual coupling between the radiating elements 2×4. Our objective is to reduce both the element separation and the mutual coupling between the patch antennas. The results show that a reduction in mutual coupling from −33.24 dB to −59.36 dB is obtained between elements at the operation frequency 5.8 GHz of the antenna array. The proposed configuration is designed, optimized, and miniaturized by using electromagnetic software CST Microwave Studio.

We present an application of the method of lines (MoL) for the analysis of a finite array of microstrip patch antennas loaded with dielectric layers on a cylindrical structure. New formulas are given in cylindrical coordinates to describe multiple, stacked layers without causing an increase in the difficulty or complexity of the analysis. We show that this model is not only numerically efficient, compared with other numerical methods, but also, shows a very good accuracy with respect to experimental results and has no limitation on antenna array geometry and excitation. Finally, some numerical results for both radiation and mutual coupling are presented.

The capability of a magnetodielectric superstrate to suppress the surface wave propagation is investigated. It is shown that the capacitively loaded loop (CLL) metamaterial (MTM) superstrate exhibits a high degree of surface wave attenuation. One of the important applications of such structure is to reduce the mutual coupling between the microstrip patch elements in array antennas. The results of numerical simulations show a significant reduction in the mutual coupling between the antenna elements. To verify and confirm the simulation results, a prototype of the CLL-MTM superstrate incorporating an array of rectangular patch antennas are fabricated and tested. The proposed two-element array antenna has a dimension of approximately $1.6\lambda \times 0.9\lambda \times 0.16\lambda $ while achieving a gain and an efficiency of 8.2 dB and 97%, respectively. Measurement shows the mutual coupling reduction of over 55 dB. The CLL-MTM superstrate provides the gain and efficiency almost the same of unloaded array antennas with 0.1 dB and 2% changes, respectively.

A novel broadband matching and decoupling network (MDN) for symmetric two-element array of microstrip patch antennas is proposed. As a distributed multiple inductive-capacitive loading, this MDN employs two groups of parallel shorting posts (vias) on the nonradiating edges of the high-coupled patches with a very-low edge-to-edge distance. This MDN excites two controllable new modified resonant half-modes, TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1/2,1</sub> and TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3/2,0</sub> , whose aggregation provides a well-matched broad bandwidth with broadside pattern. Furthermore, a reasonable offset between these two groups of vias helps obtaining a balance between the mutual capacitive and inductive couplings, and then a broadband high isolation across the overlapped bandwidth without using the conventional large isolating structures. A resonator-based equivalent-circuit model including different mutual and cross couplings is proposed and discussed to study the coupling mechanism between the modes and the antennas. Finally, the measurement proves a bandwidth of 9.8% (3.38–3.73 GHz) with an enhanced isolation of over 27 dB. A fair comparison with the state-of-the-art approaches is drawn, and greatly reduced spatial correlation (with envelop correlation coefficient (ECC) of less than 0.06) and over 72% total efficiency (with 25% increase) make the proposed design appropriate for fifth-generation (5G) multi-input–multi-output (MIMO), and the other sensitive bi-element systems.

In recent times, microstrip and patch antenna research has progressed rapidly. The challenges of design and meeting expectations of today's high speed communication have been overcome through advanced research in this field. However, the area of mutual coupling amongst large number of antennas in an array is yet to be explored at its fullest extent. This research paper is focused on a particular structure such as polygon to reduce the mutual coupling in an array of two microstrip patch antenna. Two microstrip patch antennas, located on common substrate in close proximity of each other are designed and simulated for the performance of the system. Next, the system is analyzed for mutual coupling. Through repeated design trials and measurement, the mutual coupling is reduced to about 2 dB. The other performance parameters of the system are estimated at −45 dB of return loss and 6 dBi of gain. The result is simulated and analyzed using advanced software tool.

The main objective this work is to design and simulate different shaped (S, E, C and Combined S-E-C) compact and planar micro-strip patch antenna (MPA) array for multiband wireless applications. The proposed antennas have been designed and simulated using advanced design system (ADS). Each single element antenna has dimension of 40×30 mm2 and each array consists of corresponding three or four same dimensional single elements. Micro-strip line feed technique and dielectric substrate named quartz having dielectric constant of 4.2, tangent loss of 0.0013 & height of 1.6 mm have been considered in the proposed antennas. The results have been analyzed in terms of return loss, bandwidth, directivity, gain & radiation efficiency and finally compared with literature review.

The influence of parasitic elements to self and mutual impedance is found through the idea of generalized impedance matrix in this paper. Extra ports are defined on the element to take into account the surface current on the open-circuited parasitic elements. A 3 by 3 array of dipole antenna is analyzed to verify the efficiency of this method. The idea might also be extended to analyze arrays of microstrip patch antennas.

Utilization of electromagnetic band-gap (EBG) structures is becoming attractive in the electromagnetic and antenna community. In this paper, the effects of a two-dimensional electromagnetic band- gap (EBG) Structures on the performance of microstrip patch antenna arrays are investigated using the Ansoft High Frequency Selective Simulator (HFSS TM ). A mushroom-like EBG structure is compared with 2-DEBG Structures. HFSS TM is employed to determine the effects of different Structures on two element microstrip patch antennas array. Two element microstrip patch antenna array on a uniform substrate suffer from strong mutual coupling due to the pronounced surface waves. Therefore, diverse forms of 2-DEBG Structures like: little number of holes, large number of holes, defect mode and different number of mushroom-patches columns structure are discussed. The two element microstrip patch antennas array placed on a defect in the electromagnetic (EBG) substrate that localizes the energy under the antennas. The excitation frequency of the two element microstrip patch antennas array near the resonance frequency of the defect mode can be used to control the coupling between antennas that are placed in an array. The mutual coupling improved by using large number of mushroom-patches columns structure.

Calculated data are presented on the performance of printed antenna elements on substrates which may be electrically thick, as would be the case for printed antennas at millimeter wave frequencies. Printed dipoles and microstrip patch antennas on polytetrafluoroethylene (PTFE), quartz, and gallium arsenide substrates are considered. Data are given for resonant length, resonant resistance, bandwidth, loss due to surface waves, loss due to dielectric heating, and mutual coupling. Also presented is an optimization procedure for maximizing or minimizing power launched into surface waves from a multielement printed antenna array. The data are calculated by a moment method solution.

A procedure for designing an electrically small microstrip patch antenna (MPA) is developed, wherein the length of a side of the MPA is reduced to significantly less than a half-wavelength. The MPA is loaded with a resonant circuit equivalent to that of a left-handed transmission line to artificially increase the effective wavelength of the device, thus creating a resonance equivalent to, but at a lower frequency than the unloaded {10} mode. The field distribution in the loaded MPA remains relatively unperturbed, unlike the {0} mode case that attempts to decrease the size by introducing a shorting-post; consequently, very low cross-polarisation behaviour is observed. The theory to predict the full spectrum of resonant frequencies of the antenna is developed, with finite-difference time-domain simulations used to finalise the antenna design. Finally, an electrically small ((lambda/6)times(lambda/4)) and thin (<lambda/65) antenna is fabricated at 465 MHz using low-temperature co-fired ceramic technology and tested for key figures of merit, including the resonant frequency and radiation pattern. The shortened antenna not only shows performance comparable to a conventional unloaded MPA, but also exhibits good cross-polarisation. The loaded MPA achieved an area reduction of 83% as compared to an unloaded version