Ring Patch Antenna Research Articles

Multi-band Annular Ring Microstrip Antenna with Defected Ground Structure for Wireless Communication

ring microstrip antenna (ARMSA) with a defected ground structure for multi-band operation is being proposed. Defected ground structure is produced by integrating a circular slot in the ground plane having different centre with the annular ring radiator patch. Microstrip line feed is used to excite the annular ring patch antenna placed on an FR4 substrate (dielectric constant er = 4). Results of the proposed antenna are carried out using Ansoft HFSS simulation software, and compared with the measured results, which shows good agreement. It is observed that the proposed antenna shows four bands at f1 = 2.92 GHz, f2 = 5.64 GHz, f3 = 8.21 GHz, and f4 = 10.53 GHz with an impedance bandwidth of 70%, 50%, 20% and 10% respectively. The proposed antenna is suitable for S, C and X band wireless communication system. Keywords-band, Annular Ring Microstrip Antenna, Defected Ground Structure, Microstrip line feed.

Wide Band Elliptical Ring Patch Antenna with Circular Polarization for K-Band

Wide Band Elliptical Ring Patch Antenna with Circular Polarization for K-Band

Enhanced isolation with defected ground structure in MIMO antenna

A defected ground structure (DGS) for improving isolation between four ports in a collocated multiple-input–multiple-output (MIMO) antenna is proposed. Isolation improvement by 7 dB is achieved by reducing surface waves within the dielectric substrate. Mutual coupling values as low as −25 dB are obtained along both the E- and H-planes. The MIMO antenna includes a square patch antenna surrounded by a square ring patch antenna with the DGS etched in the form of a square ring. The DGS effectively suppresses the cross-polarisation levels for all radiating modes. The design and effectiveness of the DGS in improving isolation for a fabricated 4-port antenna are discussed.

Rectangular notch loaded dual band annular ring patch antenna

In this article, a dual band annular ring patch antenna is theoretically investigated using the equivalent circuit concept.Two symmetrical rectangular notches are etched in radiating ring patch with respect to feed point. It is observed that the resonant frequency is directly proportional to the notch width and notch length. The bandwidth of the antenna at lower and higher ends are 134 MHz(1.815-1.681GHz) and 212MHz (2.849-2.637GHz) respectively for given antenna specifications. The calculated results are compared with the IE3D simulation software and previously reported results based on Artificial Neural Network (ANN). The theoretical results obtained from the proposed analysis are in good agreement with the simulated and ANN based results.

Analysis of L-probe Proximity Fed Annular Ring Patch Antenna for Wireless Applications

In the present paper, annular ring patch antenna with L-probe feeding has been analyzed using modal expansion cavity model. The proposed antenna shows wide band and ultra wide band operation which depends on the position of L-probe feeding and position of the shorting pin. For the fundamental $$\hbox {TM}_{11}$$ TM 11 mode, the bandwidth and gain is found to be 38.85 % and 7.8 dBi while for higher order $$\hbox {TM}_{12}$$ TM 12 mode bandwidth is obtained 58.71 % with corresponding gain of 6.1 dBi. The effect of shorting pin on the proposed antenna is also studied and it is found that the radiating structure is more compact in nature and improves the bandwidth upto 47.37 % with 8.0 dBi gain. Further, the proposed antenna has broadside radiation pattern over the entire bandwidth. The theoretical results are compared with IE3D simulated results which are in good agreement.

Behavioral characteristics of composite-antenna-structure covering three bands under compression load

A composite-antenna-structure covering three bands of global positioning system (1.575 GHz), digital multimedia broadcasting (2.62 GHz) and direct broadcast satellite (11.7–13.5 GHz) was designed and fabricated as a part of the structure surfaces. A new concept of antennas integrated into a composite sandwich structure provides a design that is an electrically and structurally effective multi-functional antenna structure. We designed two types of antennas. One is an annular ring patch antenna for global positioning system and digital multimedia broadcasting. The other is a microstrip patch antenna for direct broadcast satellite. In the design process, the effects of the composites and adhesive films are considered for in the design processes, because structural materials affect the antenna performance. Additionally, the composite-antenna-structure was designed by considering the coupling effect in a strict substrate. The measured results of buckling tests have provided useful information regarding not only the compression behavioral characteristics but also its degradation in electrical performance before and after the test. The experimental results have shown good results for compressive tolerance, though the specimens after compression loading returns to their original shape before failure. Additionally, an acoustic emission system is implemented in the buckling test system to study the inner behavior of the composite-antenna-structure for the reliability of secure mechanical performance. The antenna performance, as measured by the return loss and radiation pattern, remained excellent after the compression tests. These electrical performance results suggest that antennas with composite laminates will function well despite damage.

Experimental Study of Composite-Antenna-Structures with High Electrical and Mechanical Performances

Embedding of an antenna within a structural surface is an excellent way to improve structural efficiency and antenna performance. We study the impact characteristics of a Composite-Antenna-Structure (CAS) and the degradation in the performance of the antenna after impact testing. We used an annular ring patch antenna designed to operate in two bands: GPS (1.575GHz) and DMB (2.62GHz). When 20J of impact energy was applied to the CAS surface, the maximum contact force was 4kN, and the CAS proved resistant to impact. The antenna performance, measured by the return loss and radiation pattern, remained excellent after the impact tests.

A CORNER-FED SQUARE RING ANTENNA WITH AN L-SHAPED SLOT ON GROUND PLANE FOR GPS APPLICATION

This paper proposes a square ring patch antenna for GPS L1 band application. The square ring patch located on the center of an FR4 substrate was truncated a square to guide two resonant modes. The dimensions of the truncated square located on the center of the patch controls the antenna's frequency band. Larger truncated square creates longer resonant path that decreases the resonant band. To achieve the CP radiation patterns, the corner-fed method and a truncated L-shaped slot on the ground plane are applied. After the size of the truncated L-shaped slot is optimized, the currents of Eµ and E' are around 90 - shifts that make the antenna's AR lower than 3dB. By switching the positions of the feed point and the L-shaped slot, both RHCP and LHCP can be obtained individually. Beside the CP operation, the proposed design also has advantages of planar structure, simple design, low cost, and good performances.

Square Ring Antenna With Reconfigurable Patch Using Shape Memory Alloy Actuation

A pattern reconfigurable ring-patch antenna is presented. It comprises a bendable parasitic plate located in the middle of a fixed square ring. The fixed ring supports the feed, and the plate is effectively a parasitic structure. The plate's bending action is from a bisecting hinge between the rectangular halves (flaps) that can be actuated separately. The actuation is by extending a shape memory alloy spring. The restoration is by decompressing the shape memory spring action using a parallel standard spring. The parasitic plate thus reconfigures with rectangular flaps which bend up, level, and down, relative to the ring plane. As a result of the reconfiguration, the pattern of the antenna is changed while the impedance match is maintained. Simulated and experimental results are presented for the pattern and impedance of a 100 mm × 100 mm square ring patch antenna prototype operating at 1.15 GHz. The effects of some geometric parameters on the pattern and impedance are investigated in order to analyze the pattern changing mechanism. A two-element array of the reconfigurable ring-patch antenna is presented that provides further de-correlation of the patterns.

Proposed design for circular antenna and half ring antenna for UWB Application

In this paper, Ultra wideband planar circular patch and half circular ring patch antennas are proposed. These newly simulated structures are proposed for fabrication. The antennas are suitable for operating frequency of 7.5 GHz. It is shown that return loss of the both the antennas at 7.5 GHz is better than -10 dB. The VSWR obtained is less than 2. The half ring patch antenna is found to have the compact size and more bandwidth as that of circular patch antenna. HFSS11 is used for the simulation. From HFSS11 simulations, dimensions of antennas are chosen for better performance. Details of the proposed antenna design and measured results are presented in this paper

A Compact Annular Ring Microstrip Antenna for WSN Applications

A compact annular ring microstrip antenna was proposed for a wireless sensor network (WSN) application in the 2.4 GHz band. In this paper the major considerations of the conformal antenna design were the compact size and the impact on antenna's performance of a steel installation base. By using a chip resistor of large resistance (120 Ω) the antenna size was reduced to 38% of that a conventional annular ring patch antenna. With the addition of the steel installation base the resonant frequency of the antenna increases about 4.2% and the bandwidth reduces from 17.5% to 11.7% by adjusting the load resistance simultaneously. Several key parameters were discussed and optimized, and the antenna was fabricated and its performance measured. The antenna is well matched at 2.4 GHz with 34.2 dB return loss and –2.5 dBi peak gain. Meanwhile, it exhibits excellent radiation patterns with very low cross-polarization levels.

Impact evaluation of composite-antenna-structure with embedded dual-band annular ring patch antenna

In this study, a composite-antenna-structure (CAS) for a dual band of global positioning system (1.575 GHz) and digital multimedia broadcasting (2.63–2.655 GHz) was designed and fabricated as a part of a structural skin. The annular ring antenna type is available in two frequency bands, depending on the critical point view at the feeding and resonant areas. Consequently, the CAS was investigated by impact tests because the efficiency of using a protective layer needed to be confirmed. Embedding an antenna within a structural surface is an excellent way to improve both mechanical efficiency and electrical performance. The measured results not only show the impact characteristics at critical points of this CAS but also the degradation in its electrical performance after the impact test. The experimental results indicated that impact tolerance was significantly increased by the use of composite laminates. The radiation pattern strongly depended on whether composite laminates protected the antenna elements. When 20 J of impact energy was applied to the CAS surface, the specimen with the composite laminates gave twice as much contact force. The antenna performance, as measured by the return loss and radiation pattern, remained excellent after the impact tests. These electrical performance results suggest that antennas with composite laminates will function properly despite local damage.

A NOVEL TRIBAND CIRCLUAR RING PATCH ANTENNA WITH A SYMMETRICAL DOOR-SHAPED STRIP FOR WLAN/WIMAX APPLICAIONS

In this paper, a novel circular ring patch antenna with tri-band operation is proposed for satisfying WLAN and WiMAX applications simultaneously. The proposed antenna consists of a circular ring patch, a straight strip and a door-shaped strip, all of which are printed on the top side of the substrate. The straight strip embedded in the rectangular slot is aimed to obtain resonant mode at 5.5GHz. With the use of a door-shaped strip symmetrically with the microstrip feed line, the proposed antenna can operate in three separate bands. The proposed antenna has been fabricated and tested. The numerical and experimental results exhibit the designed antenna operates over triple frequency ranges, and the 10dB return loss bandwidths of the proposed antenna are 570MHz (2.27{2.84GHz), 470MHz (3.35{3.82GHz) and 1720MHz (4.84{6.56GHz), which can fulflll both the WLAN bands (2.4{2.484GHz, 5.15{5.35GHz, and 5.725{5.825GHz) and the WiMAX bands (2.4{2.6GHz, 3.4{3.6GHz, and 5.25{5.85GHz). In addition, a design evolution and a parametric study of the proposed antenna are presented to provide information for designing, modifying, and optimizing such an antenna. At last, the proposed antenna has an unusual advantage of omnidirectional radiation characteristics and stable gain over the whole operating bands.

Circularly Polarized Ring-Patch Antenna

A method is presented to enhance the flat-gain, the return-loss, and the axial-ratio bandwidths of a probe-fed circularly polarized (CP) microstrip patch antenna. The antenna occupies a volume of 124 × 117 × 33.2 mm3 (the ground plane is excluded). Bandwidths are widened by making use of an opposite shift on the inner and outer contours of a stacked ring, at an equal distance relative to the patch's boundary. The antenna is implemented in the ultrahigh frequency band for the radio frequency identification (RFID) system. The measured 10-dB return-loss bandwidth is 16.4% (835-975 MHz), and the 3-dB axial-ratio bandwidth is 7.7% (870-940 MHz). The gain is about 7 dBic within the overlapped bandwidth.

Wideband rectangular ring patch antenna with a three-pointed-star strip for WLAN/WiMAX applications

In this article, a novel wideband rectangular ring patch antenna for WLAN and WiMAX applications is presented. The antenna is composed of a rectangular ring with microstrip feed line, a three-pointed-star strip and a partial ground plane. With the three-pointed-star strip, the rectangular ring patch antenna can realize wide impedance bandwidth (return loss ≥ 10 dB) of 4162 MHz (2.384–6.546 GHz), which make it easy to cover the required bandwidths for WLAN bands (2.4–2.483, 5.15–5.35, and 5.725–5.825 GHz) and WiMAX bands (2.4–2.6, 3.3–3.8 and 5.25–5.85 GHz) applications. Details of the proposed wideband antenna design are presented and discussed. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26061

Pattern reconfigurable square ring patch antenna actuated by hemispherical dielectric elastomer

A pattern reconfigurable square ring patch antenna comprising a movable parasitic plate within the ring patch is presented. The plate is actuated using a hemispherical dielectric elastomer actuator. Small variations of the height of the parasitic plate (i.e. below, level, or above the ring patch) can significantly alter the antenna radiation pattern while maintaining reasonable impedance matching. Experimental results are presented for the radiation pattern and the return loss for different parasitic plate positions.

Frequency adjustable microstrip annular ring patch antenna with multi-band characteristics

This study introduces a frequency-tunable dual-band microstrip annular ring patch antenna design for wireless local area network (2.45 GHz) and Worldwide Interoperability for Microwave Access (3.5 GHz) applications. The proposed antenna produces realisable gain higher than 5 dBi and return loss better than 10 dB for the stated applications. The antenna design consists of an annular ring patch loaded with a slot or gap. This loaded ring excites higher-order modes around the dominant mode (TM11) of the annular ring thus making this design capable of dual-band operation. This design is realised on a 1.57 mm thick polytetrafluoroethylene substrate using a coaxial probe feed. In this study, a novel technique for independent frequency tuning has also been introduced by cutting grooves on the periphery of the ring at the desired locations. Furthermore, the design capability of multi-band operation (2.45 GHz/3.5 GHz/5.5 GHz) has also been explained in the later part of the study. Antenna operation has been verified with the help of two commercially available EM solvers (CST Microwave Studio and Ansoft HFSS Designer) and measurements. A close agreement has been found between the simulated and the measured results.

MINIATURE AND HIGHER-ORDER MODE FERRITE MIMO RING PATCH ANTENNA FOR MOBILE COMMUNICATION SYSTEM

Miniaturized ferrite ring patch antennas (RPAs) were designed and fabricated for multiple-input multiple-out (MIMO) applications. Design parameters of higher-order mode ferrite RPAs, 1-RPA and 2-RPA, were optimized, and antenna performance of the ferrite 1-RPA was evaluated. The Z-type hexaferrite and 2%-weight borosilicate glass composite was used for the ferrite antenna disk. The measured permeability (r) and permittivity (r) of the hexaferrite were 2.59 and 5.7, respectively, at 2.5GHz. Three-mode orthogonal radiation of the ferrite 1-RPA was experimentally conflrmed. With regard to the ferrite 2-RPA, excellent isolation (i40dB) between ports 1 and 2 was achieved at 2.5GHz. This excellent isolation property is attributed to both mode 3 orthogonal radiations of the bottom and top RPAs. The volumes of the 1- and 2-RPA were reduced to 14.5% and 34.5%, respectively, from 95cm 3 of a dielectric 2-circular patch antenna (2-CPA) volume.

Compact and low profile co-located MIMO antenna structure with polarisation diversity and high port isolation

A compact co-located MIMO structure with high port isolation is proposed for 2.4 GHz WLAN application. The antenna structure consists of a proximity-coupled square ring patch antenna, and a probe fed planar inverted F antenna co-located inside. The operating frequency of the two radiators is designed to be at the same frequency, and a high port isolation below −25 dB is achieved with an extremely narrow edge to edge inter-antenna space of 1 mm (0.008λ). The total lateral size of the co-located radiators is only 0.28λ×0.28λ, i.e. only about 25% of the size of a half-wavelength dual-port patch antenna. The MIMO structure gives high gains (>4.0 dB), low correlation (<0.2), and high diversity gain (about 10 dB).

Compact Tri-Band Rectangular Ring Patch Antenna with Asymmetrical Strips for WLAN/WiMAX Applications

A novel rectangular ring patch antenna with tri-band operation is presented for WLAN and WiMAX applications. The proposed antenna consists of a rectangular ring patch and a pair of straight strips with different lengths. By placing the two strips asymmetrically with respect to the microstrip feed line, the proposed antenna can operate in triple bands. The 10 dB return loss bandwidths of them are 310 MHz (2.39–2.70 GHz), 490 MHz (3.38–3.87 GHz) and 2680 MHz (4.82–7.50 GHz) respectively, which can cover both the WLAN bands (2.4–2.484 GHz, 5.15–5.35 GHz, and 5.725–5.825 GHz) and the WiMAX bands (2.4–2.6 GHz, 3.4–3.6 GHz, 5.25–5.85 GHz). In addition, the overall dimensions of this proposed antenna are 36 mm (length) × 20 mm (width) × 1 mm (thickness), which is compact compared to conventional tri-band antennas.