Annular Ring Patch Research Articles

Dual wideband circularly polarized reconfigurable antenna using gap loaded annular ring

This work presents a novel proposal for a dual wideband circularly polarized (CP) reconfigurable antenna for wideband wireless communication applications. The circularly polarized characteristic is achieved by introducing a gap in the annular ring, which leads to the generation of traveling waves in circular patterns. The concentric annular ring patch is fed using a tapered 50 Ω microstrip line. Dual wideband characteristics are obtained by incorporating concentric annular rings and additional DGS (defective ground structure) to achieve wideband characteristics. By employing PIN diodes, the proposed approach facilitates reconfiguration, allowing for both left-hand circular polarization (LHCP) and right-hand circular polarization (RHCP) in either single or dual wideband operations. The CP antenna exhibits an impressive measured axial ratio bandwidth (ARBW) of 35 % (3438–4900 MHz) and 18.75 % (5154–6252 MHz). The measured return loss bandwidths of the proposed antenna are 18.40 % (3990–4799 MHz) and 35.17 % (5161–7364 MHz). The antenna, fabricated using FR4, is compact in size, measuring 0.56 λo*0.56 λo*0.01 λo, and has a peak gain of 6.33 dBic. The simulated outcomes and hardware measurement findings agreed well.

Circularly polarized stub-loaded annular ring patch antenna for 2×2 MIMO satellite application

In this article, a stub loaded circularly polarized annular ring patch antenna which operates at 3–5 GHz band for 2×2 MIMO Satellite application is proposed. The evolution of antenna begins with a conventional annular ring patch antenna, addition of diagonal slots and integrated with λ/2 hair pin stub loaded annular ring patch to improve isolation and circular polarization. The antenna isolation is a critical parameter and important requirement of MIMO system. In satellite communications, circular polarization is used to improve the quality and reliability of the communication link between the satellite and the ground station. The antenna achieves circular polarization and mutual coupling through diagonal slots and stub-loaded design without any additional decoupling techniques. The overall size of the proposed MIMO antenna is 63 × 63 × 1.52 mm3 which is fabricated over Rogers RO3003 substrate. The proposed antenna design is simulated, fabricated, tested and analyzed for various parameters such as Reflection coefficient,Isolation Gain, radiation pattern, Axial ratio (AR), Envelope correlation coefficient (ECC), Diversity gain (DG), Channel capacity (CC) and total efficiency. The isolation of <−22 dB, gain of 7.1 dB, axial ratio<3 dB, diversity gain of 9.9 dB, ECC<0.002,CC of 11.23bps/Hz and efficiency>95% are obtained. The measured 10 dB impedance bandwidth of 270MHz and 3 dB AR bandwidth of 250MHz in the desired band are achieved. The simulated and measured antenna parameters are agreeable with each other. The results are found to be promising and having high potential in the 5G and Satellite MIMO.

Design and analysis of a compact multi-band annular ring antenna for UWB applications

In this paper a compact annular ring micro strip patch antenna with modified ground plane is proposed for UWB applications. The dimensions of proposed antenna are 30 × 26 × 1.6 mm3 which was designed on FR4 substrate with the thickness of 1.6 mm, εr = 4.4 and loss tangent parameter 0.02. To enhance the impedance bandwidth of the antenna ground plane is modifiedby extruding an inverted L shape stub and defected with multiple I shaped slots. The radiator consists of annular ringpatch, two circular stubs and one rectangular stub is included to the patch to improve the bandwidth. To design and simulate the proposed antenna CST Studio Suite 2018 is used. The proposed antenna is found with UWB frequency range of 3.1–10 GHz (S11 < −13 dB). Multiple frequency bands are observed in UWB frequency range 3.18 GHz, 6.75 GHz and8.67 GHz with the reflection coefficients of −49.6 dB, −50.2 dB and −45.7 dB respectively. VSWR is less than 2 for the total UWB frequency range. Proposed antenna is better option for UWB applications specially First and third frequency bands (3.18 GHz and 8.67 GHz) are suitable for Radio location (G59) services and second frequency band (6.75 GHz) is suitable for satellite and TV broadcasting applications. Performance of the proposed antenna is evaluated in terms of size, radiation efficiency and radiation patterns and it is better compared with existed systems.

Wideband Low-Profile Eight-Port Eight-Wave Annular-Ring Patch Antenna Based on Using Eight Dual-Shorted Dual-Resonant Ring Sectors for 8 × 8 MIMO Mobile Devices

A wideband eight-port eight-wave annular-ring (AR) patch antenna for <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$8\times $ </tex-math></inline-formula> 8 MIMO mobile devices is presented. The AR patch antenna is formed into eight dual-resonant 45o-ring sectors to radiate eight very-low-correlated or generally uncorrelated waves for <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$8\times $ </tex-math></inline-formula> 8 MIMO application. Each ring sector is loaded with two shorting pins and excited by a simple probe feed to generate its half- and quarter-wavelength resonant modes at close frequencies to form a dual-resonant wide operating band. Additionally, all 16 shorting pins of the eight ring sectors have a same distance to the patch center, thereby forming a shorting circle to function like a circular metal wall in the AR patch. This makes the surface currents coupled from the excited ring sector to adjacent sectors to be mainly confined inside the shorting circle. Therefore, with the eight probe feeds located outside the shorting circle in the AR patch, enhanced port isolation is obtained. With the proposed design, the eight-port AR patch antenna having a low profile of 1.4 mm (about <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.028\lambda $ </tex-math></inline-formula> at 5.9 GHz) and an outer diameter of 46 mm (about <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.91\lambda $ </tex-math></inline-formula> at 5.9 GHz) can generate eight very-low-correlated waves over a wide band of about 5.9-7.2 GHz (fractional bandwidth 20% based on 3:1 VSWR for mobile device application). Also, the proposed antenna has a back ground plane and is especially suitable for on-metal surface application. The use of a single proposed antenna can be conveniently applied for the mobile device or Internet-of-Things (IoT) device to cover such as 5.925-7.125 GHz for <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$8\times $ </tex-math></inline-formula> 8 MIMO operation in the possible new mobile communication spectrum.

Dual-Band Circularly Polarized Annular Ring Patch Antenna for GPS-Aided GEO-Augmented Navigation Receivers

A compact, single- feed, dual band, circularly polarized annular ring patch antenna coupled to a cross slot is proposed in this letter for GPS-aided GEO-augmented navigation (GAGAN) receivers covering L band, centered at 1176.45 MHz (L5) and 1575.42 MHz (L1) frequencies. The antenna consists of two annular rings configured by two small strips, which is coupled to a cross slot in the ground plane for gain enhancement. Circular polarization in both the bands is produced by introducing perturbations in outer annular ring and two orthogonal strips in the center space of inner annular ring. The proposed CP antenna radiates LHCP in both the desired frequencies. Two shorting pins are introduced near the feed to improve impedance matching. The simulated and measured reflection coefficient, gain, circular polarization, and axial ratio are in accord with each other. The measured 10 dB bandwidth is 2.7% (1168–1200 MHz) for the L5 and 2.5% (1560–1600 MHz) for L1. The AR bandwidth below 3 dB for the designed antenna is 1.5% (1156–1174 MHz) for L5 and 1% (1556–1572 MHz) for L1.

A Mode Decoupling Method for Circular Patch Antennas

In this contribution, we investigate the effect of mode decoupling for dual-feed circular patch antennas. We consider an antenna comprising a circular disc patch placed inside an annular-ring patch. Both patches are resonant radiators, which can be fed by two different vertical posts. Due to the field interaction of the patches, the feeds experience parasitic cross-talk limiting the receive diversity performance of the system. Here, we demonstrate the possibility to suppress the cross-talk at the operational frequency by including a capacitive decoupling element into the circular patch. The physical mechanism of the method consists in the excitation of two different eigenmodes (TM01 and TM11) in a certain combination canceling the mutual coupling. The presented decoupling method can be used for patches operating either at the same frequency or at two different frequencies. In the proposed dual-feed antenna it is possible to achieve an isolation level of better than -45 dB. In contrast to the method of decoupling and matching network used for the same type of antennas, one does not need couplers to feed the patches, which reduces losses.

A multi‐mode pattern reconfigurable antenna with wide beam coverage and its application to dual‐polarized wide‐angle scanning phased array

In this paper, radiation patterns of a single-layer microstrip antenna, which can be switched to operate under dual TM11 modes of a circular patch and a TM21 mode of a concentric annular shorted ring patch, is investigated and presented. Broadside and monopole-like patterns under multi modes are combined to broaden the antenna main-beam coverage. Besides, based on the current distributions of these modes, several slots are etched to realize antenna miniaturization. The miniaturized pattern reconfigurable antenna with a joint wide beam is applied to a dual-polarized 5 × 5 planar array, which can scan its main beam from −60° to 60° in both orthogonal planes with a gain fluctuation less than 3 dB. In addition, the array is synthesized with the convex optimization approach to obtain low sidelobe level in its wide-angle scanning range, validated by a full-wave simulation study followed by the experimental verification.

Development of an ultra‐wide band and low cross‐polarization reflectarray antenna using novel unit cells with wide‐range linear phase

In this paper, a design procedure for a linearly polarized ultra-wide band (UWB) single layer reflectarray antenna (RA) is presented. The RA is comprised of novel unit cells of annular ring patches; each ring is connected to two phase delay lines to achieve a linear and smooth phase response over a wide frequency range. In the proposed RA, the designed true phase delay provides more than three cycles of 360°. By adjusting the length of these phase delay lines, a wide range of 1300° linear phase variation has been obtained over a wide frequency band. A wide bandwidth and low cross-polarization (XP) levels were predicted using the utilized novel unit cell element and the elegant mirrored arrangement. To validate the simulated results, a prototype of circular aperture with 22.86 cm diameter was fabricated and its radiation patterns were measured. The measured 3-dB gain bandwidth of the RA is 40%, and its maximum gain, aperture efficiency and XP levels are 19.3 dB, 69% and − 35 dB, respectively, which are in good agreement with simulation.

Performance analysis of circularly polarized dual annular ring patch antenna for MIMO satellite application

ABSTRACT In this paper, a dual annular ring patch antenna with high isolation for Multiple Input Multiple Output (MIMO) Satellite application at 4 GHz is presented. The mutual coupling reduction and circular polarization are achieved by some perturbations in annular ring patch and microstrip stubs between antennas. These perturbations will excite two modes which is orthogonal ie. equal amplitude and phase shift to make it circularly polarized. The antenna design is fabricated on a substrate with permittivity 4.4 and 1.6 mm thickness. The simulated results are studied and analyzed for the proposed antenna. The isolation of better than 30 dB, axial ratio lower than 3 dB and gain of about 3.4 dB are obtained. The performance characteristics are simulated, measured and analyzed with different antenna parameters. The validated antenna shows that the simulated and measured results are in good agreement with each other.

Performance evaluation and analysis of ring loaded patch antennas

The paper presents a detailed investigation on various types of circular ring patch antennas and their importance in Wireless Communications especially under satellite Frequency Applications. The main focus is considered on the typical resonant frequencies, design parameters, theoretical foundations on shape, equivalent circuits, various applications of the ring patch antennas. Simulation and comparison of different structures of patch with annular ring patch was also presented to justify the investigation.

Four-Port Wideband Annular-Ring Patch Antenna Generating Four Decoupled Waves for 5G Multi-Input–Multi-Output Access Points

A four-Port annular-ring (AR) patch antenna generating four decoupled waves in 3.3-5.0 GHz (41% at 4.15 GHz) with antenna efficiency better than about 84% and envelope correlation coefficients (ECCs) less than 0.05 is presented for fifth-generation multi-input-multi-output (MIMO) access-point applications. The AR patch is placed 10 mm above the ground plane and its four ports are equally spaced by 90° (at φ = 0 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">°</sup> , 90°, 180°, 270°) in the patch. Each Port is surrounded by a ring gap to achieve enhanced impedance matching. Additionally, four gap-coupled shorting (GCS) strips equally spaced by 90° (at φ = 45 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">°</sup> , 135°, 225°, 315°) are added to short-circuit the patch to the ground plane, so that two adjacent ports are separated by one GCS strip. The arrangement makes the four ports capable of generating four decoupled waves with very low ECCs in 3.3-5.0 GHz. An extended design to achieve better isolation between ports is also addressed.

A triple‐band circularly polarized annular ring antenna with asymmetric ground plane for wireless applications

AbstractHerein a compact triple‐band circularly polarized (CP) microstrip patch antenna, loaded with a single annular ring patch with eight symmetrical slots along its periphery and a series of octagonal closed ring resonators (CRRs) on the opposite side of the substrate, is proposed. Evolution process of the antenna geometry reveals that the eight symmetrical slots and the CRRs are responsible for increased impedance bandwidth (IBW), while simulated (high‐frequency structure simulator (HFSS) and computer simulation tool) triple CP bands obtained due to the uses of crossshaped slit resonating at 7.5 GHz (152.2 MHz); asymmetric ground plane at 10.2 GHz (161 MHz); and square open‐loop at 12.2 GHz (112.5 MHz). Series of parasitic strips improved CP radiation and remove ripple in the radiation pattern. The antenna presented here, is compact, fabricated with an optimized dimension of 35 × 30 × 1.6 mm3, on low cost FR‐4 substrate with copper cladding. The measured &lt;10‐dB IBW ranges from 4.08‐5.05 GHz and 5.98 GHz up to 13.6 GHz. Simulated maximum peak gain found to be 4.45 dBi at 13 GHz. The antenna proposed herein is appropriate for wireless applications.

Design, simulation and measurement of triple band annular ring microstrip antenna based on shape of crescent moon

In this paper a novel structure of an annular ring patch microstrip antenna based on Shape of Crescents Moon (SCMs) is designed, simulated and measured to operating with multiband applications. It is different parameters such as input impedance, return loss, gain, surface currents and radiation patterns were studying. This design consists of five SCMs in different sizes. Three of SCMs are arranged inside the annular ring patch and the others two are located outside. It is found that the proposed antenna possess triple band frequency which signify the multiband and compactness of antenna. The fabricated antenna is resonating at threefrequencies11.30, 18.07 and 20.72 GHz. This design is simulated using Ansoft High Frequency Structure Simulator (HFSS) and it compared with the obtained measurement data. Interestingly, the comparison results are in good agreement. The bandwidths of measured return loss at −10 dB corresponding with the X-, Ku- and K-bands frequencies which are 474, 620 and 810 MHz, respectively. Also, the antenna designed is useful for many services operations at these bands frequency and it is applications.

A 320 GHz Octagonal Shorted Annular Ring On-Chip Antenna Array

In this paper, an octagonal shorted annular ring (OSAR) antenna array is presented based on 130-nm SiGe BiCMOS technology without any post-processes. The OSAR antenna consists of annular ring patch, an array of shorted pins and ground which is formed a cavity to enhance the gain and reduce surface waves. The 1 x 2 OSAR antenna array is designed and fabricated with the die area of 550 x 1100μm 2 . The measured -10-dB impedance bandwidth is more than 17 GHz (303-320 GHz). The proposed on-chip antenna array is achieved a measurement perk gain of 4.1 dBi at 320 GHz and the simulated radiation efficiency of 38 %.

L/S Multiband Frequency-Reconfigurable Antenna for Satellite Applications

A novel multiband frequency-reconfigurable antenna is presented. The designed antenna can realize L-band single-frequency operation and S-band dual-frequency operation through electronic tuning. Annular ring and sawtooth patches are used as radiators for L/S-band operation and are excited by a broadband reconfigurable orthogonal network through the coupling of a T-shaped slot and a ring slot in the ground plane, respectively. By changing the bias of the p-i-n diodes loaded on the feed network, the operating frequency can be switched between the navigation state and the satellite link receiving state. A high tuning frequency ratio (1.64:1) is obtained. The simulated and measured results show good agreement. Good impedance matching (VSWR <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$&lt; $</tex-math></inline-formula> 1.3) and circular polarization characteristics (AR <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$&lt; $</tex-math></inline-formula> 3) are obtained in all three operating bands. Achievement of a highly reconfigurable frequency ratio of a circularly polarized antenna provides solutions for multifunction CP antenna aperture sharing.

Cavity model analysis of differential dual‐polarised annular‐ring patch antenna

The four-port cavity model is presented to study a differential dual-polarised annular-ring patch antenna operating at higher order mode TM12. Acceptable agreements among calculated, simulated, and measured impedances and radiation patterns are obtained. Theoretical analysis shows that the differential port-to-port coupling impedance is zero, and its isolation is theoretically infinite. The differential input impedance is about four times of the single-ended input impedance at the resonant frequency of higher order mode TM12. The differential operation can suppress the adjacent modes TM02 and TM22 near the operating mode TM12 and lead to a more symmetrical E-plane radiation pattern and lower cross polarisation level.

A Simple and Efficient Approach to Compute the Operating Frequency of Annular Ring Patch Antennas by Using ANN with Bayesian Regularization Learning Algorithm

A Simple and Efficient Approach to Compute the Operating Frequency of Annular Ring Patch Antennas by Using ANN with Bayesian Regularization Learning Algorithm

Modified annular ring patch fed cylindrical dielectric resonator antenna for WLAN/WIMAX applications

ABSTRACTThis article investigates modified annular ring patch fed cylindrical dielectric resonator antenna (CDRA) with hybrid mode excitation. The present article comprises of two main aims (i) generation of HE11δ and HE12δ mode in CDRA with the support of modified annular ring patch, both the hybrid modes radiates in broadside direction and (ii) achieve triple band characteristics by using the concept of hybrid antenna. The proposed antenna design is functioning in three different frequency bands, i.e. 1.92–2.3 GHz, 3.13–4.6 GHz, and 5.4–6.5 GHz. The simulated outcomes are verified by using archetype of proposed antenna. The practical outcomes indicate good settlement with simulated outcomes. The proposed antenna structure is appropriate for WLAN/WiMAX applications. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:120–125, 2017

Hybrid cylindrical dielectric resonator antenna with HE11δand HE12δmode excitation for wireless applications

In this article, dual mode triple band hybrid cylindrical dielectric resonator antenna CDRA for different wireless applications is investigated. It is seen that annular ring shaped patch along with T-shaped printed line behaves as a magnetic and electric dipole concurrently and create HE11I´ and HE12I´ mode in the proposed CDRA. Both of the hybrid modes radiate in broadside direction. The concept of hybrid antenna the combination of annular ring patch and CDRA is used to achieve triple-band feature in the proposed antenna. Ansoft HFSS-EM simulator is used to optimize the proposed antenna. Optimized simulated results have been practically confirmed by using the archetype of proposed antenna. The proposed radiator is applicable in three different frequency bands, that is, 2.24-2.56 GHz, 3.28-4.18 GHz, and 5.36-5.8 GHz. It is appropriate for WLAN 2.4/5.8 GHz and WiMAX 2.5/3.3/5.5 GHz applications.

Low-profile UHF RFID reader antenna with CP radiation and coupled feeding technique

A low profile annular-ring patch antenna with circularly polarized (CP) radiation for radio frequency identification (RFID) reader applications in the ultra-high frequency (UHF) band (922-928 MHz) is presented in this article. Perturbation method is applied by loading a pair of triangular open-notch into the outer circumference of ring patch, and good impedance matching can be determined by using the coupled feeding technique. The overall size of this proposed antenna is 150 mm × 150 mm × 10.4 mm. The measured results show desirable 10-dB impedance bandwidth and 3-dB axial ratio (AR) bandwidth of 3.5% (908-941 MHz) and 0.65% (922-928 MHz), respectively. Stable antenna peak gain and efficiency of 7.2 dBic and 87% are also exhibited, respectively.