Profile Antenna Research Articles

Low profile pattern‐switchable multibeam antenna consisting of four L‐shaped microstrip lines

A multibeam antenna consisting of a set of four L-shaped microstrip line sections is presented for pattern switchable applications. A planar electromagnetic band gap substrate is implemented to reduce the antenna profile to λ 2.45 /35, where λ 2.45 is the free space wavelength at a design frequency of 2.45 GHz. An impedance matching network is integrated on the lowest layer below a ground plane. The microstrip lines have a resonant frequency of 2.45 GHz and are excited separately. When one of the strips is excited, the antenna generates a tilted beam with a gain of 8.6 dBi. By switching the excitation strip sequentially, a full azimuth beam steering is achieved. When the antenna is located above a large conducting reflector, the antenna maintains its performance. Thus, the antenna is a candidate for moving objects with high speed internet and vehicular tracking.

Design and Demonstration of a RADAR Gauge for <italic>In-Situ</italic> Level Measurement in Furnace

A specially designed air-cooled compact antenna is proposed for non-contact real-time radio detection and ranging (RADAR)-level measurement in furnace. 3-D modeling is used to optimize the surface profile of the RADAR antenna for beam symmetry and low sidelobe level over 20–24 GHz. The fabricated RADAR sensor deployed in mono-static mode has 0.19-mm measurement error for a static target. Measurements in a closed furnace at 1100 °C demonstrate the feasibility of non-contact in-situ monitoring of the level of molten metal for long duration (11 hours) without degradation in the sensor performance.

Optimized Design of a Microstrip Patch Antenna for Radar Applications

Radars demand low profile and light weight antenna subsystems. Microstrip antennas possess these characteristics and serve as an alternative to the bulky and heavy weight reflector/slotted waveguide array antennas, thus an ideal choice for radars. Here, a single line fed microstrip antenna with pierced corners is designed. This antenna has improved parameters compared to the conventional square microstrip antenna. The main problem encountered is in designing the patch antenna with optimum values for various antenna parameters. In order to solve this problem, an alternative solution used is Artificial Neural Networks (ANN). The antenna is also optimized using Particle Swarm Optimization (PSO). The parameters considered in all the cases are return loss (S11) and VSWR which was designed using FEKO software. The designed antennas are found to radiate in the C-band, which covers frequencies in the range 5-8GHz, applicable in most of the modern radars. The simulation design is carried out using CADFEKO suite.

Very‐low‐profile, 2.4/5‐GHzWLAN monopole antenna for large screen‐to‐body‐ratio notebook computers

AbstractA very‐low‐profile, 2.4/5‐GHz monopole antenna well suited for large screen‐to‐body‐ratio notebook computers with an ultra‐thin bezel for wireless local area network (WLAN) applications is presented. The antenna height was 4 mm only, and the design was constructed on a low‐cost dielectric substrate of size 4 mm × 30 mm to be easily placed within the ultra‐thin bezel surrounding the top edge of the notebook computer display. The antenna consisted of two radiating arms of unequal lengths to generate the lower and the higher bands. By properly loading each radiating arm with a shorting chip inductor, the proposed antenna was capable of generating the 2.4‐GHz (2400–2484 MHz) and the 5‐GHz (5150–5825 MHz) WLAN bands with a very low antenna profile. Good radiation characteristics were also obtained. The proposed design provides a feasible solution to the internal small antennas demanded by the current trend of the thin‐bezel notebook computers.

A Novel Four Element Low Profile and Compact Conical Dielectric Resonator Antenna for Wideband Applications

In this paper, a four element Conical Dielectric Resonator Antenna fed through coaxial probe is presented. This Low Profile and compact novel Antenna is designed for Wideband application and its input and radiation characteristics determined through the Ansoft High Frequency Structure Simulator (HFSS) Software. The proposed antenna provides wide Bandwidth (45%) and high average gain (5.15 dBi) with Monopole type Radiation Pattern.

Low‐profile circularly polarised patch–ring antenna with compact feeding network

This study presents a low-profile circularly polarised microstrip antenna with two radiators composed of a corner-truncated patch and a corner-truncated ring. They are stacked and printed on the two sides of a suspended FR4 substrate. The axial ratio (AR) bandwidth of the proposed design is greatly improved compared with the traditional patch by merging the existing bandwidth of the patch with the additional bandwidth of the ring. Parametric analysis indicates that the modes of the patch and the ring can be tuned independently. A λ /4 microstrip line is meandered in the inner part of the ring to reduce the size of the feeding network. The antenna profile is only 0.065 λ . A prototype of the proposed antenna is built and tested. The simulated and measured results agree well. The measured 10 dB return-loss bandwidth is 20.6% (2.375-2.88 GHz) and the 3 dB AR bandwidth is 6.94% (2.39-2.56 GHz). The measured gain is ~7 dBiC in the concerned bandwidth, with a variation of 1 dB.

An Optimized Inset Feed Circular Cross Strip Antenna Design for C-Band Satellite Links

This proposed antenna model and progressing the investigation of an inset fed wideband circular slotted patch antenna is suitable for 5.2 GHz satellite C-band applications. A circularly shaped slot has been chosen to be etched on diminutive square patch (4.4cm*5.64cm) of the inset feed antenna. The object of this work is to develop an efficient and inexpensive transducer system to facilitate its compatibility with monolithic microwave integrated circuits; expenses are minimized for its fabrication and trail low profile for C-band satellite links. This paper focuses on the circular profile of the microstrip patch antenna intended for the proficient gain to enhance the performance of the satellite communication. The return loss of -21.79dB with the directivity 8.22dB and gain of 8.17dB have been estimated. The efficiency of 97% with VSWR of 1.22 compensates each other with better simulation results.

Mutual Coupling Reduction and Pattern Error Correction in a 5G Beamforming Linear Array Using CSRR

A four-element printed antenna array operating at 25-GHz frequency with complementary split ring resonator (CSRR) has been proposed for beamforming applications. The CSRR elements have been used to suppress the mutual coupling in the proposed array. The existence of the CSRR configuration in antenna array controls the unnecessary surface current flow between the array elements, and thus the mutual coupling between array elements has been significantly reduced up to −55 dB. The effect of mutual coupling on the array radiation patterns has been studied in the presence and absence of CSRRs. The effectiveness of the CSRR has been studied by steering the main beam as well as the nulls in different angles. By implementing the CSRR elements in array antenna, the distorted array patterns have been recovered and are presented. The proposed antenna array with the CSRR has the advantage of easy and low-cost fabrication and it offers excellent coupling suppression without changing the antenna profile. The commercially available simulation tools such as MATLAB and Ansys HFSS have been used for array weights calculation and antenna design respectively. Finally, the fabricated prototype has been experimentally verified, and it shows that the analytical and computed results agree well with the measured results.

A Compact and Low-Profile MIMO Antenna Using a Miniature Circular High-Impedance Surface for Wearable Applications

A new miniature circular high-impedance surface (HIS) is used to design a compact and low-profile multi-in multi-out (MIMO) antenna for wearable applications. The antenna is designed to operate from 2.4 to 2.49 GHz for wireless local area network application. By employing a pair of degenerated characteristic modes of a circular loop antenna, the MIMO antenna can achieve a good port-to-port isolation (>15 dB) without increasing its geometric size. A four-element HIS is chosen to match the antenna profile, and a 2 dBi antenna gain improvement is observed. The design was optimized considering the effect of packaging and then a prototype with the optimal parameters was fabricated and tested. Measurement results are in good agreement with simulation results. Furthermore, the loading effect due to lossy human tissue is also considered and the results show that the antenna has a robust performance against the human phantom and a low specific absorption rate can also be obtained.

A Review on Monopole and Dipole Antennas for In-Building Coverage Applications

This paper presents a review of several antennas topologies applied for indoor applications. Few requirements are desired for those antennas fo rtheir suitability for indoor applications. Such as antenna size, antenna profile, simple structure, omnidirectional radiations, polarization, and sufficient bandwidth to cover the most wireless communications bands, including GSM, LTE, WLAN ,WiFiand WiMAX. This paper focuses on minimizing the number of antennas needed to cover all these frequencies while offering convenient polarization to mitigate the fading problems and multipath effects losses. To meet these requirements, a monopole antenna with circular polarization is suggested. In addition, various topologies of monopole and dipole antennas are discussed in this paper in terms of their advantages and challenges. Moreover, this review is helpful to understand the current developments in indoor antenna topologies and it proposes a new antenna with a sufficient design for modern indoor applications.

Design Approach to a Novel Dual-Mode Wideband Circular Sector Patch Antenna

A design approach to a novel wideband circular sector patch antenna is proposed. Design guidelines are laid down based on an approximate 1.5-wavelength, multimode magnetic dipole, and the cavity model. Then, the flared angle of the circular sector patch and the corresponding usable resonant modes for wideband radiation are determined. It is demonstrated that the resonant TM4/3,1 and the TM8/3,1 modes within a 270° circular sector patch radiator can be simultaneously excited, perturbed, and employed to form a wideband unidirectional radiation characteristic with two resonances. Prototype antennas are designed and fabricated to experimentally validate the dual-resonant wideband property on a single-layered substrate. It is further demonstrated that the antenna designed on a 5-mm-thick air substrate exhibits an available radiation bandwidth (ARB) of 14.5%, while the printed one designed on a 2-mm-thick modified Teflon substrate exhibits an ARB of 6.5%. It is evidently validated that the proposed approach can be employed to effectively enhance the operational bandwidth of microstrip patch antennas without increasing antenna profile, inquiring multiple radiators or employing reactance compensation techniques.

A Miniaturized Circularly Polarized Implantable Annular-Ring Antenna

A novel miniaturized circularly polarized (CP) annular-ring microstrip antenna with a smooth profile is presented for Industrial, Scientific, and Medical (ISM) band (2.4–2.48 GHz) implantable applications. The radiating element of the antenna consists of an annular ring and a central circular patch. The CP radiation is generated by adding a pair of open stubs in the inner boundary of the annular ring. The antenna profile is minimized by properly cutting two kinds of rectangular slots onto the annular ring. Furthermore, the Z-shaped slot on a central circular patch is implemented for improved axial ratio (AR) and better impedance matching. The volume of the proposed antenna including substrate and superstrate is ${\text{120.69 mm}}^{3}$ , which is smaller than the other CP implantable antennas with similar performance. Simulated and measured −10-dB impedance bandwidth are 8.3% and 11.4%, respectively. The simulated 3-dB AR bandwidth is 2.49%. In addition, the radiation and specific absorption rate performance of the antenna are also characterized. It is a capable candidate for implantable applications.

The Design and Simulation of High Impedance Surface in Airborne Telemetry Antenna

Aiming to the problems that excessive reduction of airborne telemetry antenna’s size will cause a sharp deterioration of the antenna’s bandwidth and gain, this paper proposed that using a high-impedance surface in the airborne telemetry antenna. As the size and bandwidth of the high-impedance surface is far from being able to meet the application requirements, this paper designed a new high-impedance surface which can be applied to the telemetry transmitter antenna, and reduced the profile size of the telemetry antenna and increased the gain of the antenna at the same time. In addition, based on the equivalent circuit model, we have resolved the contradictory situation of small size and wide band gap in the high-impedance surface design. The results show that the low profile, high gain and wide bandwidth of the telemetry antenna can be achieved by using the new high-impedance surface. The antenna structure and design ideas presented in this paper can significantly improve the performance of airborne telemetry antenna.

Toroidal Plasma Lens Antenna

This letter proposes a novel toroidal plasma lens with circular polarization, as an alternative solution for electronic warfare antennas. The aim of the proposed solution is to reduce the antenna profile and the radar cross section, thus minimizing the probability of target detection. The results compare the performance of the proposed antenna to a conical horn and to a spherical/elliptical lens. The toroidal plasma lens achieved equivalent gain, with reduced antenna profile and reduced near-field backscattering from the plasma toroid, thus maximizing the true power delivered to the far-field region.

Wideband and Low-Cross-Polarization Planar Annual Ring Slot Antenna

This letter presents the design of a wideband and low cross-polarization single-layer annual ring slot antenna. By adopting differential feeding, the cross-polarization level could effectively be lowered while ensuring a low antenna profile. The structure of the substrate integrated waveguide back cavity improved the antenna gain, and the extra two short-circuit stubs added a new resonance point, extending the bandwidth. Furthermore, a modified circular ring slot was adopted to further improve cross-polarization performance. The measured −10 dB impedance bandwidth of the antenna was 51% (9–15.17 GHz), the gain in passband was about 9 dBi, and the cross-polarization level was below −35 dB. Compared to other similar antennas, the proposed antenna features an apparent improvement in terms of gain, cross-polarization level, and bandwidth.

An optimal antenna motion generation using shortest path planning

This paper considers an angular velocity minimization method for a satellite antenna. For high speed transmission of science data, a directional antenna with a two-axis gimbal is generally used. When a satellite passes over a ground station while pointing directly at it, the angular velocity of the satellite antenna can increase rapidly due to the gimbal kinematics. The high angular velocity could exceed the dynamic constraint of the antenna. Furthermore, micro vibration induced by high speed antenna rotation during an imaging operation might cause jitter, which can degrade the satellite image quality. To solve this problem, a minimum-velocity antenna motion generation method is proposed. Boundaries of the azimuth and elevation angles of the antenna within an effective beam width are derived using antenna geometry. A minimum-velocity azimuth profile and elevation profile within the boundaries are generated sequentially using a shortest path planning method. For fast and correct generation of the shortest path, a new algorithm called a string nailing algorithm is proposed. A numerical simulation shows that the antenna profile generated by the shortest path planning has a much lower angular velocity than the profiles generated by previous methods. The proposed string nailing algorithm also spends much less computation time than a search-based shortest path planning algorithm to generate almost the same antenna profiles.

A Microstrip Rectangle Carpet Shaped Fractal Antenna for UWB Applications

Recently the microstrip patch antennas (MPA) has evolved into a most dynamic and indigenous field in the arena of UWB demanding low profile and mini antennas with ample frequency choice for ultra wide (UWB) applications. Thus the paper focuses on thorough analysis of a novel rectangular microstrip patch with carpet shaped fractal antenna fed by microstrip line for applications in Ultra- Wideband. The basic antenna structure is rectangular microstrip patch which is modified by adding slotted rectangular shape with partial ground plane at the rear end is iterated using fractal geometry that exhibits more bandwidth and reduce return loss. The proposed antenna has a compact size 50×42mm2 with height 1.6mm and designed on low cost FR4 (er = 4.3) substrate. A wider bandwidth (-10 dB) of around 3.1 – 8.25 GHz with stable radiation pattern is achieved and E-field, H-field current distributions are also examined. When compared with the existing traditional UWB antennas, the recommended antenna exhibits good characteristics, low profile and more so cost-effective. By using CST MW studio software the Proposed UWB antenna is designed and simulated to verify antenna parameters for improvements.

Theoretical anisotropic transverse resonance technique for the design of low‐profile wideband antennas

The authors derive an anisotropic transverse resonance technique enabling the design of a low profile, wideband radiating rectangular cavity. They calculate a tapered geometry that preserves an effective half wavelength resonance within a cavity partially loaded with an anisotropic medium. This design results in an antenna profile of λ o/24, with 1.4 octaves of bandwidth, and a realised gain of 3.3–7.2 dB from 210 to 505 MHz. Using an adaption of a coaxial line to waveguide transition, which utilises two flat rectangular probes as a two-port matching network, as well as an external 180° hybrid coupler as a phase splitter, they achieve a voltage standing wave ratio of better than 2:1 across the whole band.

Wideband microstrip antenna loaded by elliptical rings

The paper presents elliptical ring-loaded microstrip antennas for wideband applications. The parasitic stack elliptical rings bring in new resonances to enhance antenna bandwidth while maintaining the characteristics of compact size, low profile, and reasonable good polarization of microstrip antenna. By utilizing one or two elliptical rings upon a reference microstrip antenna (RMA) as parasitic, more resonances appeared as the rings operated as half-wavelength resonators. Thus, two and three resonances are observed for the one ring-loaded microstrip antenna (ORLMA) and dual ring-loaded microstrip antenna (DRLMA), respectively. The antennas maintain compact size and low-profile characteristics, and the volumes of RMA, ORLMA, and DRLMA compared to their corresponding low edge free space wavelength are 0.345 λ × 0.285 λ × 0.020 λ, 0.330 λ × 0.273 λ × 0.038 λ, and 0.392 λ × 0.287 λ × 0.037 λ, respectively, while their measured bandwidth increased from 2.8 to 6.3 and 7.0%. Reasonable good polarization and radiation patterns are also obtained for the antennas.

Радиоголографический метод контроля профиля параболических зеркальных антенн по электромагнитному полю в ближней зоне

Радиоголографический метод контроля профиля параболических зеркальных антенн по электромагнитному полю в ближней зоне