dBi Gain Research Articles

A Micro-Acoustic Enhanced Low-Impedance Antenna System for IoT Wake-Up Receivers

In this work, we propose a passive radio frequency (RF) front-end tailored for wake-up receivers (WuRx) to be deployed in cellular IoT devices and wearables networks, featuring a low radiation resistance antenna and a high-Q matching network implemented with microacoustic resonators integrated to obtain a systematic higher node’s sensitivity at no cost in terms of power consumption. We show how these components can be co-designed to obtain high passive voltage gain, hardwarelevel blocker immunity, and increased resilience to integration parasitics, relaxing link budget for low-power IoT nodes. We report experimental validation of a PCB antenna with 2 dBi gain measured on an 11Ω input resistance at resonance, and an in-house fabricated Micro-Electro-Mechanical System (MEMS) thin-film aluminum nitride bulk acoustic resonator with a quality factor Q = 550 and a piezoelectric coupling coefficient k2 t =7%, hybridly integrated with a commercial off-the-shelf low-power WuRx circuit to benchmark the proposed RF front-end design at 850MHz. We demonstrate a passive voltage gain of 12 dB due to the MEMS resonator, and an additional 11 dB due to the proposed antenna design (for a total of an unprecedented 23 dB passive gain in this frequency range) leading to an over the air.61dBm minimum detectable input power and 23 dB blocker rejection.

D-Band Integrated and Miniaturized Quasi-Yagi Antenna Array in Glass Interposer

An integrated and miniaturized D-band quasi Yagi antenna in glass interposer is presented. Single element, 1×2 and 1×4 test coupons are fabricated on 100-μm glass substrate with low-loss polymer buildup films and the return loss, gain and radiation pattern of the antennas are characterized. The proposed antenna utilizes a monopole radiator to achieve a higher bandwidth. Advantages of the glass substrate for beyond 5G communications in terms of enabling fine features and compact integration of other active and passive devices through chip embedding is discussed. An analysis of the substrate modes to ensure proper mode propagation in the selected stack-up is presented. Furthermore, the paper discusses the challenges in planar antenna measurements in sub-THz frequencies and it presents two measurement setups to overcome these challenges. The first is a low-cost probe-station-based measurement setup to characterize the return loss and boresight gain, and the second is a diode-detector-based setup to measure the normalized radiation pattern. The proposed antennas achieve high bandwidth covering the frequency range of 110-170 GHz, and 4.78 dBi, 8.41 dBi, and 11.04 dBi gain for the single element, 1×2 and 1×4 array, respectively.

A broadband Butler-based dual-polarized omni-directional antenna

AbstractThis paper presents a broadband Butler-based slant ±45° dual-polarized omni-directional antenna working at the frequency band of 1.69–2.69 GHz for extending wireless communication network capacity in the limited service size. The proposed antenna realizes a 360° full coverage with wider bandwidth in a compact cylinder and increases the network capacity to 6 × 6 MIMO instead of using three traditional 2 × 2 MIMO omni-directional antennas. Theoretical analysis, simulation, and fabrication are conducted to validate the idea of the proposed omni-directional antenna. The measured results show 46% bandwidth with 15 dB return loss, 2.2 dB azimuth null and 8.9–10.5 dBi gain for port-C with 0° phase increment, and 14.1 dB azimuth null and 9.6–10.6 dBi gain for port-L/R (left/right) with ±120° phase increment, respectively.

Beam‐squint rectified balanced antipodal Vivaldi antenna with sliced fins and quarter‐wavelength labyrinth director

AbstractThis paper introduces a gain‐enhanced, beam‐squint rectified balanced antipodal Vivaldi antenna (BAVA) with symmetrically sliced fins and a novel square‐shaped metallic labyrinth director. The proposed antenna operates from 2 to 18 GHz with S11 less than −10 dB maintaining a fractional bandwidth of 160%, realizes 12.564 dBi as maximum gain at 18 GHz, and achieves greater than 3.415 dBi gain throughout the functioning band of frequency. Improvement of broadside gain by reconfiguration of current loops through symmetric slicing of radiating flares and beam‐squint correction using quarter‐wavelength labyrinth director are addressed by the proposed antenna. The maximum realized size of the antenna is 80 × 40 × 0.508 mm3. Consistent radiation patterns are observed at selected frequencies. Numerical evaluation with a full wave simulation tool and consequent experimental validation with a compact antenna test range is performed.

Planar metasurface sub-reflector based dual-reflector antenna for multi-directional beaming

This paper presents a novel planar metasurface subreflector (MSSR) array-based dual-reflector antenna inspired by Cassegrain arrangement for simultaneous beaming in far-field microwave wireless power transfer at f0=2.45 GHz for the first time. The MSSR unit cell exhibits 94.8% reflection and 0.0065λ0 thin geometry where λ0=122.45mm is the operating wavelength. The antenna exhibits optimum gain at focus F=0.93λ0, and with variation in F, required beamwidth and sidelobe levels can be easily achieved. The experimental studies show 15.8 dBi gain and 13.4°, 25.2° half power beamwidths in E- and H-plane, respectively in the main direction. When the MSSR array is placed at F, the measured electric field shows a nearly equal concentration in three directions. This is to be used to power small IoT devices at different angles simultaneously. This work may serve as a design guide for designing the planar MSSR-based dual-reflector antenna in the microwave domain.

Monopole Cavity Resonator Antenna with AMC and Superstrate for 5G WiMAX Applications

For 5G and WiMAX applications, a coplanar waveguide (CPW)-fed monopole antenna sandwiched between an artificial magnetic conductor (AMC) and a superstrate is investigated. Because traditional planar antennas have low gains, they are unsuitable for a wide range of applications. This paper explores scientific strategies for increasing radiation gain in low-gain antennas such as planar monopoles. We use AMC in conjunction with superstrate to achieve a high gain antenna, with the monopole antenna serving as the primary radiator. However, a superstate like this demands the use of materials with high permittivity, and most of such materials are not readily available on the market. Even if such materials are available, they are mostly expensive and unsuitable for commercial systems. We investigate various superstrates and elaborate on which way these superstrates can be used interchangeably without compromising antenna performance. In the end, we fabricate one of these three superstrates. The antenna, which also employs AMC in tandem with the superstrate, has an impedance bandwidth ranging from 3.2 GHz to 3.75 GHz with 7 dBi gain, so it can be a viable candidate for 5G and WiMAX applications

Hybrid βΩ-Indexing Fractal Slotted Multiband Antenna for Electronics Wireless Sensor Applications

In this proposed work a compact, low profile, inset-fed βΩ-space-filling curve-based slotted fractal antenna for multi-band wireless applications and narrow band operations is designed, fabricated, and successfully tested. The measured results of the reflection coefficient and E-plane and H-plane gain radiation patterns are found to be very concord with simulated corresponding results. The antenna resonates at five resonance frequencies 1.91GHz (1.86-1.93GHz), 3.12GHz (3.03-3.21GHz), 5.56GHz (5.50-5.60GHz), 10.75GHz (10.55-11.20GHz) and 13.94GHz (13.72-14.17GHz) with narrow band. Therefore the proposed antenna is adopted for the applications like PCS-1900 (n2 band: 1850-1910MHz), rail mobile radio (1900-1910MHz), DCS-IMT gap (n98/n39 band: 1880-1920MHz), WCDMA (1900MHz), X-band (10.55-11.20GHz) and Ku-band (13.72-14.17GHz) applications. The antenna parameters gain, directivity, and efficiency are greatly improved by the 50% reduction in ground length. A Good impedance matching is achieved by the use of inset feeding with a 50Ω port at an operating frequency 3.1GHz. The antenna exhibits 2.94dBi gain at the operating frequency. A new hybrid βΩ- space-filling curve has been utilized for the slotted fractal proposed antenna design. The antenna is fabricated on an FR4 substrate with compact dimensions (39.05mm x 32.25mm x 1.6mm) at a frequency 3.1GHz.

Rectangular Microstrip Array Feed Antenna for C-Band Satellite Communications: Preliminary Results

This paper proposes a rectangular array configuration of microstrip antennas combined with a parabolic reflector for C-band satellite communications. The antenna operates in the frequency range of 3.8–4.2 GHz. In particular, the proposed antenna is a 2 × 2 feed antenna on a parabolic system. It uses a multilayer microstrip array antenna with proximity coupling and coaxial probe techniques as a feeding technique. The fabricated antenna operates at 3.8–4.4 GHz and 12.1 dBi gain at frequency 4.148 GHz. Through simulation, combining the antenna with a 2.4 m parabolic reflector results in a gain of 33.1 dBi. In conclusion, the proposed antenna configuration achieves the expected high gain and narrow beamwidth for the E plane and the H plane.

Meta-surface (frequency selective surface) loaded high gain directional antenna systems for ultra-wideband applications

<span lang="EN-US">In this work, a meta-surface (frequency selective surface) loaded high gain directional antenna system is presented. The antenna system is developed using ultra-wideband (UWB) antenna element and meta-surface reflector. The UWB antenna element is designed and simulated without meta-surface reflector. The UWB antenna element has poor impedance bandwidth and directivity. A meta-surface is created using unit cell and equal in the size of the antenna substrate. The meta-surface is placed over the UWB antenna element at optimized height (H=30 mm). The impedance bandwidth, directivity and gain of the proposed antenna are improved by the meta-surface reflector. The proposed antenna is fabricated and experimentally validated by the comparison of the simulated and measured results. The antenna has 3 to 6 GHz wide impedance bandwidth, more than 5 dBi gain and maximum 4.6 dBi directivity at 3.5 GHz frequency. Performance of the proposed antenna is also compared with existing carried out work. Comparatively, the proposed antenna with high directivity is most suitable for IEEE 802.15.4a UWB wireless sensor network (WSN) security application.</span>

High-Gain Millimeter-Wave Antenna-in-Display Using Non-Optical Space for 5G Smartphones

This article presents a high-gain display-integrated antenna topology, for the first time, embedding radiating traces into a nonoptical space, referred to as the dead space (DS), which is the edge part of the display panel; however, it does not perturb the optical illumination of the display. Thus, the proposed antenna topology is denoted as antenna-in-display (AiD). To fit the extremely narrow embedding conditions of the given DS (= <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.03 \lambda _{0}$ </tex-math></inline-formula> at 28 GHz), a new-shape coplanar waveguide (CPW)-fed folded dipole antenna was devised and efficiently tailored in the DS area. The bottom side of the panel was modified to render the effect of a coplanar defected ground structure (CDGS) for antenna minimization, and a new asymmetrical antenna geometry was proposed for wideband impedance matching and broadside radiation pattern. Compared with conventional studies, the proposed antenna concept provides an improved gain resulting from the good conductive metal in DS, the complete display visibility, and touch sensor compatibility, whereas the previous antenna-on-display (AoD) approaches inherently suffer from the limited gain obtained at the expense of lower conductivity of the optically invisible antenna electrodes. Because the proposed AiD concept enables the direct fabrication of antenna traces into the DS area of the display panel, eliminating need for an additional film, a lower package profile, and cost reduction can be achieved. The proposed prototype was fabricated and verified using an actual smartphone. The measured data confirm 12.32 dBi gain, 54.3% radiation efficiency, and 3 dB gain bandwidth larger than 3 at 28 GHz.

Antenna Array on Glass Interposer for 6G Wireless Communications

This paper demonstrates integrated packaging solutions for antenna components in D-band by using glass-based package. We design sub-terahertz patch antennas at 140 GHz frequency band using HFSS simulation, and form arrays of patch antennas for 6G (sub-THz) wireless communication applications. The patch antennas and feeding networks are implemented using microstrip structures on the top of the interposer, with ground planes beneath. Build-up layers of polymer dry films are laminated on a glass core for multi-layer copper metallization, and copper structures are patterned on the polymer layers. For precise fabrication of the antenna and feeding structures in package, we implement the semi-additive patterning process to deposit the copper structures. Adequate measurement methods are applied to address difficulties in D-band antenna measurements. By forming patch antenna arrays, we obtain 10 dBi gain using a 4-element linear array and 14 dBi gain using a 4-by-4 2-D array. The bandwidths achieved for these arrays are 7% (10 GHz) and 5% (7 GHz), respectively, based on return loss measurements. Overall, the measurement results present good match to simulation. Antenna structures on glass substrates demonstrated in this paper represent the basic building block for heterogeneous integration of D-band front-end module in glass-based packages.

High Gain and Wide-Angle Continuous Beam Scanning SIW Leaky-Wave Antenna

A novel substrate integrated waveguide (SIW) adopting a leaky-wave antenna (LWA) for continuous beam scanning for tri bands is presented. For continuous beam scanning (CBS), optimization of different parameters associated with the unit cell has been carried out. Apart from this, optimal impedance matching is also obtained with the help of the characteristic impedance of the waveguide. The proposed SIW LWA scans from −58° to + 59° along with 14.50 dBi gain when the frequency changes from 10 GHz to 18.22 GHz and provides a scanning rate of 14.23. The beauty of the suggested antenna is its smaller size and high gain, along with a wider scanning range (117°) capability. This antenna’s final prototype has been fabricated, and the measurement results are matched with the simulation results.

Wideband high gain SIW horn antenna loaded with half Maxwell fish‐eye fabricated by 3‐D‐printing

AbstractThis letter presents a wideband high gain substrate integrated waveguide horn antenna (SIWHA) loaded with half Maxwell fish‐eye (HMFE) fabricated by 3‐D‐Printing. The impedance bandwidth of the SIWHA is narrow, mainly caused by the discontinuity between the substrate with the air. By introducing the HMFE and a match layer between the SIWHA with HMFE, the impedance continuity can be realized, which can not only improve the impedance bandwidth but also enhance the antenna gain. Experimental results show that the proposed antenna can achieve more than 6 dBi gain and 60.9% relative impedance bandwidth with reflection coefficients lower than −10 dB.

A Compact Filter and Dipole Antenna With Its Phased Array Filtenna and ADMM-BO Learning for Use-Case Analog/Hybrid Beamforming in 5G mmWave Communications

In this article, a 5G compact millimeter-wave dipole antenna with high gain and its array filter-antenna is proposed, following a theoretical discussion is proposed. To increase the gain and focused mainbeam, the double dipole is inserted at the ground plane. The results show that the proposed antenna has an impedance band-width (IBW) of around 7.14% and 6.7 dBi gain at 28 GHz. Next, a 5G filter is proposed with 4% IBW and lower than 0.6 dB gain insertion loss. A simple phase-shifter with 2-bit structure is designed in an 8-elemens array filter-antenna with <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.35\lambda $ </tex-math></inline-formula> spacing between the two elements which uses a meander-line to reduce mutual-coupling. First, the phased-array filtenna (filter-antenna) is fabricated to meet the analog beamforming challenge. The IBWs of the array filter antenna are approximately 3.5% with a high gain of 15 dBi. Second, a novel machine learning method is proposed as an alternating direction method of multipliers and Bayesian Optimization (ADMM-BO) is used in the hybrid beamforming for such partially-connected phased-array structures. Simulation and measurement results show that the proposed antenna and its array have a high gain in analog and hybrid beamforming and acceptable data rates. The data-rates of this array reach 100 Mb/s in SNRs higher than 10 dB. The amount for 0 dB SNR is 75 Mb/s. These results also indicate that the mainbeam shift is in the range of [−50°, 50°] with a gain in variations of around 1.5 dB and side lobe level (SLL) of about −10 dB at 50°.

A Multi Stub Polygon Shaped Textile Antenna for Deformation Performance Using Aperiodic DGS

A compact fully flexible antenna with 1.22 as dielectric constant with 0.016 loss tangent is designed for wearable biomedical applications. It has dimensions of 40.5 x 23 x 0.97 mm3. The polygon-shaped patch is modified to achieve ultra-wideband frequencies using partial ground as 16.5mm and a periodic vertical slot of 13x2 mm2 structure in defected ground structure to enhance the wide bandwidth of 2.6-11.1 GHz. Using a transmission line equation and a microstrip line feeding method, the resulting antenna operates at a biomedical frequency in open space and on the body-worn case with multi band i.e. 3.1 and 5GHz. The deformation process works well for the proposed antenna without affecting its actual bandwidth with 20 to 60 mm radii. Additionally, the proposed antenna operates at 5GHz for Wi-Fi with 3.67dBi gain, -35.1dB as S11 which is suitable for commercial applications. CST Microwave Studio was used to simulate the antenna and fabricate it for testing.

Low Profile Meandered Printed Monopole WiMAX/WLAN Antenna for Laptop Computer Applications.

The research on wireless communication demands technology-based efficient radio frequency devices. A printed monopole dual-band antenna is designed and presented. The presented antenna exhibits a promising response with improved bandwidth and gain. The antenna radiates from 3.49 GHz to 3.82 GHz and from 4.83 GHz to 5.08 GHz frequencies with 3.7 dBi and 5.26 dBi gain, having a bandwidth of 9.09% and 5.06%, respectively. The novelty in the developed antenna is that resonating elements have been engineered adequately without the use of the additional reactive component. The cost-effective FR 4 laminate is utilized as a substrate. This structure exhibits an efficiency of over 83% for both resonances. The numerically computed results through simulations and measured results are found to be in good correlation. The aforesaid response from the antenna makes it an appropriate candidate for laptop computer applications.

Design of a Wide-Bandwidth, High-Gain and Easy-to-Manufacture 2.4 GHz Floating Patch Antenna Fed with the Through-Wire Technique

This paper presents a feasibility study for designing a floating patch antenna structure fed with a probe from a microstrip. The main premise is to eliminate the dielectric in the patch design, which is equivalent to having an air dielectric and leads to the necessity of proper support to fasten the patch in the air. The novelty of this paper is that this new device, apart from being fed with the though-wire technique directly from the microstrip line, has to be, by design, robust and easy to manufacture, and, at the same time, it has to present, simultaneously, good values in all of the performance indexes. A prototype has been designed, manufactured, and measured with good performance results: a bandwidth higher than 10% around 2.4 GHz, a radiation efficiency higher than 96%, a 9.63 dBi gain, and a wide beamwidth. The main advantages of this prototype, together with its good performance indexes, include its low fabrication cost, low losses, light weight, robustness, high integration capability, the complete removal of the dielectric material, and the use of a single post for feeding the patch while simultaneously fixing its floating position.

Design and Simulation of Rectangular Microstrip Patch Antennas (45 GHz and 60 GHz) for V-band Applications

In this article, two wideband microstrip rectangular patch antennas have been designed and simulated for V band communication systems at resonant frequencies 45 GHz and 60 GHz. Rogers RO4730G3 is used as substrate dielectric with dielectric constant 2.98. The dimensions of the antennas are 6.23mm*6.7mm*0.7mm and 6mm*6.4mm*0.7mm respectively, with very simple geometrical configuration. To investigate the performance, the designs were then simulated using (CST) Studio Suite software package. The dimensions have been well studied and optimized to obtain acceptable results of Voltage Standing Wave Ration (VSWR), return loss, gain, bandwidth (BW) and radiation pattern. The 45 GHz antenna provides a gain of 6.73 dBi with the BW of 5.5 GHz and 1.03 of VSWR. Meanwhile, the 60 GHz design offers 6.92 dBi of gain with BW of 11.57 GHz and 1.05 of VSWR. The achieved results illustrate that both designs provide a good performance and are applicable for future 5G communication systems or any applications in the V band region.

Asymmetric meshed ground Balanced Antipodal Vivaldi Antenna with quarter-wavelength labyrinth director for ultrawideband microwave applications

This paper introduces a new compact Balanced Antipodal Vivaldi Antenna (BAVA) with asymmetrically meshed ground, square shaped metallic labyrinth and dual scale edge treatment. The proposed antenna operates from 4 GHz to 18 GHz with S11 less than −10 dB, 127.27% fractional bandwidth and realizes greater than 4.01 dBi gain throughout the functioning band of frequency and achieves a maximum of 13.46 dBi at 17 GHz. Group delay of less than 5 ns signatures are realized. Improvement of operating bandwidth through enhanced impedance matching by finely meshed pattern on the ground planes and containment of rate of change of deflection angle using quarter-wavelength labyrinth director are addressed by the proposed antenna. The maximum realized size of the antenna is 80 × 40 × 0.508mm3. In addition, consistent radiation patterns are observed at selected frequencies. Numerical analysis with a full wave simulation tool is performed to calculate the radiation characteristics of the antenna and are experimentally validated.

A New Efficient Array Architecture for Small L-Band Secondary Surveillance Radars with Reduced Number of Elements

ABSTRACT In this paper, a new and more efficient array architecture for small Secondary Surveillance Radar (SSR) antennas is presented. The architecture uses a side element for the generation of the Control (CTRL) beam as a new proposed method and is applied on a 7-element 1.5-m SSR antenna array. All three required patterns for secondary surveillance radar containing SUM, DIFF, and CTRL are designed and implemented in an integrated one-sheet feed network. The array antenna uses Taylor distribution for SUM port, obtaining 16 dBi and 16.7 dBi of gain at 1030 MHz and 1090 MHz, respectively, and a side lobe level of 23 dB at the measurements. It is demonstrated that the last side element at the edge is the best choice for CTRL pattern with respect to the final pattern shape, maximum achievable gain, and easy implementation in this small array architecture, which results in more than 60% of aperture efficiency. The simulation and measurement results are in acceptable agreement.