A highly miniaturized patch antenna

In this paper, we have proposed a Slotted Microstrip Patch Antenna with a Defected Ground Structure (DGS). Here, we have integrated the concept of DGS and Slotted Patch Antenna in order to get enhanced bandwidth and gain. The proposed antenna consists of a microstrip fed slotted rectangular patch with E-shaped cut in the ground plane. The performance of this antenna is discussed and analyzed with the variations in patch width and number of slots. The variations in Return Loss (S11), Radiation Pattern and Gain of the designed antenna are analyzed for different case studies. The antenna shows a dual band characteristics having a return loss of below −20 dB at 3.2–3.5 GHz and below −10 dB at 5.6–5.8 GHz, which is suitable for IEEE 802.16 WiMAX and IEEE11p WLAN applications. CST MWS 2015 is used to simulate the antenna structure.

A rectangular microstrip antenna (RMSA) designed for dual-band response using defected ground structure was reported. Configuration was tested on economical rate glass–epoxy substrate placed at 1.5 mm from ground plane. Two rectangular slots and an elliptical slot were introduced in ground structure which results in dual-band operation at 2400 MHz and 5800 MHz with gain of 4.3 dB and 7.4 dB, respectively. However, a clarification of resonant modes that is responsible for getting dual-band operation was not given in the reported work. In this paper, using resonance curve plot, return loss plots, and vector surface current distributions, detailed analysis is given explaining dual-band response of reported work. From the analysis done, it is observed that variations in dimensions of slots embedded on ground plane modify the various mode frequencies that results in dual-band response. The selection of feed and placements of all slots results in matched impedance at TM01 and TM20 modes of operation.

: This paper presents a two element microstrip antenna array using trapezium shape defected ground structure (DGS). The DGS is inserted in the ground plane between two elements of antenna array. Insertion of the DGS is intended to suppress the mutual coupling effect produced by antenna array. Simulation and measurement results were taken and compared between antenna array with and without DGS. Measurement results show that the antenna with DGS compared to antenna without DGS can suppress mutual coupling effect to 7.9 dB, improve the return loss to 33.29% from -30.188 dB to -40.24 dB and axial ratio bandwidth enhancement to 10 MHz. This bandwidth enhancement is achieved from frequency 2.63 GHz – 2.67 GHz for antenna without DGS and from frequency 2.63 GHz – 2.68 GHz for antenna with DGS. In addition, the DGS antenna also improved the antenna gain to 0.6 dB. The results show that the implementation of the trapezium DGS can improve the radiation properties of the antenna without DGS.

This chapter presents the study of performance parameters of stub loaded oval-shaped patch antenna using dumbbell-shaped metamaterials (MTM), electromagnetic bandgap structures (EBG), and defective ground structures. Metamaterials are loaded inside the substrate that is mounted on the partial ground plane. EBG and DGS structures utilize full ground planes. The partial ground plane has the dimensions of 10 × 6 × 0.035 mm3 and the full ground plane has the dimensions of 10 × 12 × 0.035 mm3. Many features like impedance bandwidth, gain, axial ratio, and miniaturization of the proposed patch antenna are studied using metamaterials, electromagnetic bandgap structures (EBG), and defective ground structures. The appropriate structure will be chosen depending on the wireless application. Metamaterial loaded patch antenna is recommended for wide bandwidth applications, patch antenna mounted the EBG ground is recommended for small antenna applications, and patch mounted on the DGS ground is recommended for high gain applications.

A comparative study to determine the most highly sensitive resonant frequency among the first four resonant frequencies of a conventional patch antenna and defected ground structure (DGS)-loaded patch antennas using commonly used DGS geometries in the literature, such as a rectangular slit, single-ring complementary split ring resonators (CSRRs) with different split positions, and double-ring CSRRs (DR-CSRRs) with different locations below the patch, for relative permittivity measurement of planar materials was conducted. The sensitivity performance for placing the DGS on two different locations, a center and a radiating edge of the patch, was also compared. Finally, the effect of scaling down the patch size of the DGS-loaded patch antenna was investigated in order to enhance the sensitivities of the higher order resonant frequencies. It was found that the second resonant frequency of the DR-CSRR DGS-loaded patch antenna aligned on a radiating edge with a half scaled-down patch size shows the highest sensitivity when varying the relative permittivity of the material under test from 1 to 10. In order to validate the simulated performance of the proposed antenna, the conventional and the proposed patch antennas were fabricated on 0.76-mm-thick RF-35 substrate, and they were used to measure their sensitivity when several standard dielectric substrate samples with dielectric constants ranging from 2.17 to 10.2 were loaded. The measured sensitivity of the second resonant frequency for the proposed DGS-loaded patch antenna was 4.91 to 7.72 times higher than the first resonant frequency of the conventional patch antenna, and the measured performance is also slightly better compared to the patch antenna loaded with a meander-line slot on the patch.

An investigation of novel techniques in the designing of a low profile, horizontally polarized omnidirectional (HPO) patch antenna with omnidirectionality in the H-plane using a defected ground structure is presented in this study. The HPO patch antenna is designed by sequentially etching four rectangular and four open diagonal slots symmetrically on the patch and the antenna's ground plane. It creates four quarterwavelength open stubs that produce an in-phase circulating current on both the ground and the patch. Narrow bandwidth is achieved by using the four quarter-wavelength open stubs and by printing sequential slots only on the ground. Another set of four quarter-wavelength shorted stubs is achieved by sequentially etching four rectangular and open diagonal slots on the patch to resonate with another frequency and to increase the bandwidth by merging these two resonance frequencies. Combining these two resonance frequencies covers the applications of 2.39–2.52 GHz WiFi bands. The overall dimension of the proposed antenna structure is 0.32 λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> ×0.32 λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> ×0.006 λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> with 5.51% bandwidth and moderate gain of 2.2dBi and roundness within 1 dB in the azimuth plane.

A new microstrip patch antenna that resonates on more than one frequencies and yields sufficiently high bandwidth is presented. Several variations of the proposed design are simulated using practically used dielectric materials. Detailed input return loss plots, VSWR plots, and radiation pattern plots are presented. A comparative study of all simulated results is presented. The design that yields the best performance is chosen for further optimization using deliberately-created defects in the ground plane, called Defected Ground Structures (DGS). It is observed that improvement in bandwidth is achievable through using the DGS.

In this work, a novel bludgeon-shaped microstrip patch antenna with defected ground structure (DGS) is recommended for UltraWide Band (UWB) i.e., (3.1–10.6 GHz) applications with band notch characteristics. The encouraged antenna is simulated and fabricated using RT DURIOD 5880 substrate with epsilon value of 2.2 having the scale of 60 × 60 × 1.6 mm3. The circular-shaped patch is chosen with radius of 14 mm and 50 Ω microstrip line feeding technique is used for the simplicity of the design. The circular slots and circular-shaped patch are delivered to improve the radiation traits and overall performance of the recommended antenna. To acquire the UWB frequency of operation, rectangular defected ground structure (RDGS) is implemented in the ground plane. Further, three rectangular slots of different dimensions are etched to accomplish the band notch configuration. The recommended antenna is simulated using 3D electromagnetic simulation tool CST MICROWAVE STUDIO Version16. The evolved antenna is tested using MS46122B 20 GHz vector network analyzer. The effectiveness of the antenna is proven the usage of the specifications like return loss (S11), VSWR, and simulated radiation patterns.

This paper presents a novel slotted rectangular dual-band (28/42GHz) patch antenna for fifth generation (5G) network applications. A simple microstrip patch antenna of the size 8×8×0.8 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> has been proposed having impedance bandwidth of 2/9.2 GHz for 28/42 GHz transmission frequency, to resolve the issues of the required compactness, high gain and improved efficiency of the 5G wireless applications. Rogers RO4350 (lossy) is used as a substrate material having dielectric constant and thickness of ε <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">r</sub> =3.66 and 0.8 mm, respectively. For the resonant frequencies of 28.2 GHz and 42 GHz, the gain of 6.2 dB is achieved for the entire considered bandwidth and a directional radiation pattern is achieved for millimeter-wave transmission. A defected ground structure (DGS) is formed by placing a rectangular slot under the ground, underneath the feed line of a microstrip patch antenna (MSA) which results in improving of the gain. The comparison of the DGS, full ground, and the effect of the slot technique are shown in detail with simulation results in CST. The results for return loss, VSWR, gain, efficiency, directivity, and current distributions shows that the proposed antenna is well suited for the 5G applications in the millimeter-wave region.

A microstrip patch antenna using a defected ground structure (DGS) to suppress higher order harmonics is presented. An H-shaped defect on the ground plane with only one or more unit lattices has been utilized and yielded bandstop characteristics. Compared with a conventional microstrip patch antenna without the DGS unit cell, the radiated power of the DGS patch antenna at harmonic frequencies has been drastically decreased.

The design of planar filter using stepped impedance type distributed synthesis has been proposed for 8.6–9.5 GHz frequency band. To improve the return loss characteristics, instead of using traditional defected ground structure (DGS), the combination of fractal geometry and DGS, known as ‘fractal DGS’ has been embedded in the ground plane of the filter. The filter using fractal geometry gives 65% better return loss as compared to filter without DGS. Three laboratory prototypes (without DGS, first iteration DGS and second iteration DGS) have been developed to validate the simulated and measured results. The measured results are agreed with simulated one.

Over last few decades, wireless communication system has sought more attention and plays predominant role in different areas for human personal and commercial applications. Day by day, with advancements in technology, wireless gadgets got more compact due to microelectronics fabrication and integration techniques. So, such applications put great demand over new design specifications on antenna structures used in transmitter and receiver for radio wave communication. In wireless applications depending upon, frequency bands and bandwidth requirements numerous compact antenna structures are used with improved efficiency. Microstrip patch antennas are highly regarded due to its compact size, easy integration with microwave circuits. In study of patch antenna, Defected Ground structures gain popularity these days due to its various benefits to enhance antenna performance. This research article, provides extensive literature survey over use of Defected Ground Structures (DGS) in microstrip patch antenna with its design consequences. This article also explores the enhancement in antenna parameters with implementation of DGS’s. DGS concept is used in microstrip patch antenna and microwave engineering for performance improvement of these devices. DGS can be merged with other techniques to enhance antenna operational parameters like gain, bandwidth, VSWR and spurious radiations.

ABSTRACTIn this article, the performance of compact planar wearable antenna 4.1 × 4.1 cm2 mounted on different phantoms and human body fed by microstrip line is designed to operate in ultra‐wide band applications. The proposed antenna consists of a circular patch with notch‐cut and U‐shaped slot on the upper side of the substrate and finite ground plane with rectangular shape defected ground structure (DGS) on the lower side. The U‐shaped slot and finite ground plane are used to achieve an enhanced impedance bandwidth. The proposed antenna is designed and simulated using Ansoft High Frequency Structure Simulator (HFSS) to verify its operation over larger frequency range from 3.6 GHz to 15 GHz. The return loss, VSWR, radiation pattern, and gain are investigated in this article and verified with the experimental measurements. The proposed wearable antenna radiates over a wide frequency band and can achieve nearly omnidirectional radiation patterns with an average gain of 3.11 dBi. A good agreement between simulations and practical measurements can be achieved in order to verify the suitability of proposed wearable antenna to be used in various UWB applications. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:2531–2536, 2016

This paper describes a coaxial probe-fed slotted antenna with Defected Ground Structures (DGS) which can be tuned to resonate at our desired frequency bands by changing the position of DGS and width of the slots in the ground plane. The proposed antenna can be made to work in the WLAN (2.4/5.2/5.8 GHz) band and WiMAX applications. In this paper, we have tried to reflect a detailed study of the slots in the ground plane and its effect on the antenna parameters such as gain, polarization, return loss, radiation pattern, etc. The proposed antenna produced a multi-band application providing return loss of 11.81 dB at 1.69 GHz, 18.81 dB at 2.5 GHz, 19.59 dB at 2.89 GHz, 22.98 dB at 4.81 GHz, 19.80 dB at 5.80 GHz and 12.70 dB at 6.17 GHz by using FR-4 Epoxy substrate with dielectric constant (Ɛr) of 4.4 and a substrate height (h) of 1.60 mm.

Microstrip patch antenna is widely presented based on its advantages, especially for WiMAX wireless applications. Although, reducing the antenna size is a distinguished topic of antenna development, the antenna performance significantly drops for a small antenna. In this paper, two slots on a compact square ring and defected ground structure (DGS) are presented for bandwidth enhancement and radiation efficiency at 5.5 GHz. When the DGS and slots are embedded in the structure of the designed antenna, two major improvements are achieved. Enhanced impedance bandwidths with |S11|< −10 dB range from 5.041 to 5.88 GHz (15.25%) and the radiation efficiency of 80.8% by loading DGS over conventional patch antenna are achieved. Both antennas with/without DGS achieve good far-field radiation patterns within the operating frequency band at 5.5 GHz. CST microwave studio is used for simulating the design. The physical antenna layout is printed on FR4 substrate. The proposed configuration has a miniaturized size of 25 × 25 mm2. The fabricated antenna is tested to validate the proposed design. Thus results obtained from simulations and measurements show good agreement. The proposed prototype can be considered a suitable candidate for WiMAX wireless applications.