U-shaped Patch Research Articles

A Wideband High Gain Differential Patch Antenna Featuring In-Phase Radiating Apertures.

Communication systems need antennas with wide bandwidths to provide large throughput, while imaging radars benefit from high gain for increased range and wide bandwidths for high-resolution imaging. This paper presents the design and evaluation of a wideband, high-gain antenna that achieves an average gain of 9.7 dBi over a bandwidth of 1.49 GHz to 3.92 GHz by using multiple in-phase radiating apertures. The antenna has a unique structure with a central rectangular short-circuited patch sandwiched between two back-to-back U-shaped radiating patches and two flanking H-shaped short-circuited patches. Each of the U-shaped patches employs a coplanar waveguide as feeding to achieve ultra-wideband impedance matching. Benefiting from design arrangement, in-phase electrical field distributions appear at the gaps between the patches that result in equivalent radiating magnetic currents in the same direction. Theory analysis shows that the close-spaced, same-direction magnetic currents created by the radiating apertures intensify the radiation and increase antenna gain within its impedance bandwidth. Simulated data show that the use of the coplanar waveguide feeding and short-circuited patches increase the bandwidth from 65 MHz to 2.43 GHz. Moreover, the short-circuited patches increase the gain by 3.45 dB at 2.4 GHz. Simulation and measurement results validate the design and show that the antenna features a maximum gain of 11.3 dBi and an average gain of 9.7 dBi in a fractional bandwidth of 89.8%. Because of the high gain values and the wide bandwidth, the antenna is particularly suited for long-range communication systems and high-resolution radar applications.

Wideband 1-bit reconfigurable transmission metasurface unit cell design in Ka-band with polarization hold and conversion

In this paper, a wideband transmission unit cell is proposed for programmable metasurfaces operating in the Ka-band. The unit cell features a compact period of only 2.91 mm, corresponding to 0.34 λ0 at the center frequency of 35 GHz. A receiving layer, consisting of a patch loaded with two PIN diodes, is utilized to achieve 1-bit phase modulation, while a U-shaped patch serves as the transmitting layer to enable selection of linear polarization hold or conversion. Based on the multi-resonance principle, the proposed unit cell exhibits broadband behavior, as demonstrated by simulation results under periodic boundary conditions, which indicate a 3 dB transmission bandwidth of 29.4–40 GHz (30.5%). Two unit cells were fabricated and tested in a standard waveguide, with the minimum insertion loss of the two states tested being 1.2 dB and 3 dB bandwidths of 30.1–31.2 GHz and 33.5–38.5 GHz, respectively. The maximum 180° phase error is 10°, indicating the high quality of the proposed unit cell.

Wideband Transmit-Array Antenna Design With Dual-Layer Ultrathin Huygens’ Meta-Surface for Vehicular Sensing and Communication

This paper proposes a wideband high-gain transmit-array (TA) antenna for vehicular sensing and communication, which employs a dual-layer ultrathin Huygens' meta-surface (HMS). It consists of a 33 × 33 HMS unit cells-based TA, a feeder horn, and a three-dimensional printed fixture to hold them. Each HMS unit cell has two identical metal patterns (MPs) of two symmetrical U-shaped patches and one H-shaped patch, which are distributed on both surfaces of the ultrathin substrate. A pair of top U-shaped patches form the first single-wavelength loop mode, and another pair of bottom U-shaped patches forms the second single-wavelength loop mode. Due to the different phases of the incident waves on the top and bottom U-shaped patches, the two loop modes are generated at different frequencies. A third half-wavelength dipole mode is provided by the H-shaped patch. The three modes correspond to three different frequencies, forming a wide transmission frequency band. Three near-unity transmission peaks are yielded to ensure high and stable aperture efficiency (AE). As well, the transmission phase of the HMS unit cell varies with geometric dimensions, and five unit cell types are quantized to obtain 360° phase range with a low loss of less than 2.6 dB. To verify the design concept, a prototype is fabricated. Measurements show a 3-dB gain bandwidth of 17.9%, a maximum gain of 30.5 dBi at 26.2 GHz, and a high AE of 41.9%. It has unidirectional radiation pattern while reducing backlobe.

A Compact Dual-Wideband Magnetoelectric Dipole Antenna for 5G Millimeter-Wave Applications

A compact dual-wideband millimeter-wave magnetoelectric (ME) dipole antenna based on dual-mode operation is proposed in this article. The ME dipole consists of two mirrored U-shaped patches, a substrate integrated waveguide (SIW) cavity with slotted top and two metallized vias connecting the patches to the slot. The two mirrored U-shaped patches work as an electric dipole (E-dipole), while the slot on the top of the SIW cavity and two metallized vias works as a magnetic dipole (M-dipole). In the lower frequency band, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.5\lambda $ </tex-math></inline-formula> modes of the E-dipole and the M-dipole are excited to form the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.5\lambda $ </tex-math></inline-formula> mode of the ME dipole. In the higher frequency band, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1\lambda $ </tex-math></inline-formula> modes of the E-dipole and the M-dipole are excited to form the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1\lambda $ </tex-math></inline-formula> mode of the ME dipole. In order to achieve compact structure and wide bandwidths, an SIW cavity is designed to feed the antenna. The proposed design shows that the measured impedance bandwidths (return loss larger than 10 dB) are 24–29.3 and 35.5–43.5 GHz at least with the achieved gain of 4.8–6.1 and 6.8–8.7 dBi, respectively. The designed antenna is suitable for 5G dual-band millimeter-wave applications.

Compact, broadband, and thin corrugated U-shaped patch-constituted MIMO antennas for airborne UAV applications

AbstractThe major component for the effective functioning of airborne unmanned aerial vehicles (UAVs) is an antenna. The unified integration of an antenna with UAVs without disturbing the other components of UAVs, compact size, thin, and wideband antennas are preferred. Based on these prerequisites, a low-profile and a wideband antenna is presented for autonomous UAVs for C-band applications. The antenna is designed on an extremely thin substrate of size 0.01λ0 without compromising the antenna's broad bandwidth. The antenna structure comprises a corrugated U-shaped patch, a few parasitic patches along with the partial ground. Initially, only a single mode was excited using a U-shaped patch, then further on introducing a few more parasitic patches along with corrugations in a U-shaped patch other modes were also coupled leading to enhancement in the bandwidth of the antenna. The proposed antenna along with a 2 × 2 quad-port multiple input, multiple output (MIMO) antenna is designed and fabricated. The measured results are found to be in good agreement with the simulated results. A broad bandwidth of 74.5% (4.1–9.0 GHz) with 5.02 dBi peak gain at 6.6 GHz is exhibited by the fabricated MIMO antenna. Thus, the designed antenna proves to be an effective candidate for UAV-based C-band applications.

A dual‐band high‐gain magneto‐electric dipole antenna array for millimeter‐wave applications

In this article, a compact dual-band magneto-electric dipole (MED) antenna array with high gain is proposed, which is fed by a 1-to-4-way feeding structure composed of substrate integrated waveguide (SIW) aperture-coupled. The dual-band MED antenna consists of a pair of U-shaped patches of different sizes used as electric dipoles and two pairs of vertical metalized vias work as magnetic dipoles. By analyzing the working mode of the MED unit at each resonance frequency and the complementary principle of radiation patterns, the dual-band characteristics of the antenna are further illustrated. Measured results of the fabricated antenna array show that -10 dB impedance bandwidth is 12.5% (from 22.5 to 25.5 GHz) with a peak gain of 11 dBi in the low-frequency band and 5.9% (from 40.5 to 42.9 GHz) with a peak gain of 10.5 dBi in the high-frequency band. Moreover, the radiation patterns in E-and H-planes are almost symmetrical at two operating bands with the maximum gain in the z-direction. The proposed dual-band MED antenna array has the merits of high gain, easy integration and simple structure.

Dual-band trident shaped MIMO antenna with novel ground plane for 5G applications

A trident-shaped dual-port high isolation MIMO antenna is proposed. The overall dimensions of the proposed design is 62 × 25.6 × 1.524 mm3. By utilizing an arrow-shaped strip in between the U-shaped patch along with the defected ground plane, dual-band characteristics is achieved. This design demonstrates dual frequency bands varying from 2.99 to 3.61 GHz and 4.53 to 4.92 GHz with corresponding isolation ≤−25 dB and ≤−16 dB, respectively. The measured realized gain and radiation efficiency of the proposed design vary in the range from 2.96 to 3.14 dBi & 3.69 to 3.84 dBi and 72.68 to 80.24% & 85.22 to 84.64%, respectively. The important diversity parameters such as ECC, DG, MEG, CCL, TARC are studied to verify the practical applications of the design. The group delay analysis is also performed at two different orientations of the antenna. The CST microwave studio simulation software is utilized to theoretically model the MIMO design. Moreover, the prototype design is fabricated for practical validation. This antenna successfully covers the 5G and sub 6G n77/n78/n79 spectrum for high data rate communication.

A Compact High-Selectivity Wideband Filtering Antenna With Multipath Coupling Structure

A compact wideband filtering patch antenna with high selectivity is presented. The proposed filtering antenna contains a rectangular patch rounded by a pair of U-shaped patches, and is fed through two coupling slots etched on the ground. By introducing these elements, four in-band resonances are generated and the impedance bandwidth are expanded. Besides, multiple coupling paths are constructed from the feeding port to the radiating patches to form three radiation nulls at the band edges. Moreover, a modified composite right/left-handed transmission line unit is used as the feedline to further suppress the out-of-band radiation level. The performance of the proposed filtering antenna is verified by both simulation and measurement. It exhibits a 21.5% (4.45–5.52 GHz) measured impedance bandwidth with a compact size of 0.4 λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> × 0.4 λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> (where λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> is the free-space wavelength at 5 GHz). Besides, the measured average gain and out-of-band suppression level are 4.8 dBi and 15.9 dB, respectively. Obviously, this filtering antenna can be used to build a compact multiband antenna array to reduce the interference between different bands.

Design of Six Port Antenna With Frequency Diversity and Diverse Radiation Pattern

Based on shared U-shaped patch, a six port antenna with frequency and radiation pattern diversity is investigated in this paper. Two evolutionary U-shaped patches are cascaded together to form a three port antenna with a common ground. Three probes located at the two ends and the middle of the U-shaped patch are used to provide excitation with different phases. In order to improve the impedance bandwidth of each port, both T-shaped and rectangular stubs are loaded on the ground plane. When different ports are excited, the vector currents on the U-shaped patch and the T-shaped stubs show diametrically opposite flow directions, resulting in the diversity of the antenna in frequency and radiation pattern. Two three port antennas form a six port antenna with a relatively compact distance of 0.23&#x03BB;. The measured results show that the frequency diversity is specifically manifested as when port 1, 3, 4, 6 are excited respectively, the six port antenna operates in 4.73-5.02 GHz with a peak gain of 5.38 dBi. And, when port 2, 5 are separately excited, the antenna works at 3.80-4.40 GHz with a peak gain of 5.01 dBi. Meanwhile, the six port antenna exhibits diverse radiation patterns with better total efficiency up to 84.8%. Furthermore, the port isolation in the two operating bandwidth is better than 21.7 dB and 18.5 dB, which also indicates that the designed six port antenna can be applied for 5G.

Sustainable dual-band microstrip patch antenna with paper-based substrate and aluminum for multipoint distribution systems and WiMAX application

In this study, a microstrip patch antenna design with a U-shaped patch and a paper-based substrate is presented. Metallic parts such as the patch, ground plane and microstrip line feed are designed in aluminum. Utilization of recyclable paper and aluminum yields a sustainable and environmentally friendly design. The dual-band antenna operates between 1.950-2.125 GHz and 2.650-2.825 GHz with a bandwidth of 0.175 GHz for both frequency ranges. It is suitable for multipoint distribution systems (2.076-2.111 GHz) and WiMAX application (2.700-2.800 GHz). Monopolar radiation patterns are obtained for the operation frequencies of both frequency ranges. Maximum gain values are 5.009 dBi and 5.413 dBi for the operation frequencies of multipoint distribution systems and WiMAX application, respectively. While the antenna can be used indoors and outdoors, radome design is not considered in the structure. No parasitic elements or slots are included in the antenna. All simulations are carried out by using AN-SYS HFSS software package.

Evaluation & Comparison between Plus Sign Slotted and U-shaped Microstrip antennas for Wi-MAX application using IE3D

In this paper, a slotted patch antenna of Microstrip antenna (MSA) type has been put forward. The enrichment in gain is realized by cutting slots of suitable dimensions in the rectangular patch using the technique of probe feed. Optimum feed providing the required outcome is found. Simulation of the two projected antennas had been carried out by means of IE3D software. Performance assessment would be grounded on altering the patch dimensions, the acquired results are compared especially in gain, the efficiency of the antenna, the pattern of radiation, VSWR, and return loss with a U-shaped patch antenna.

A Metamaterial Loaded Microstrip Patch Antenna for Lower 5G U-NII Spectrum

In this study, we have proposed a metamaterial loaded microstrip patch antenna for the sub-6 GHz range to operate in the Unlicensed National Information Infrastructure (U-NII) band. The Proposed Microstrip Patch Antenna (PMPA) has a U-shaped patch and an array of Complementary Split Ring Resonators (CSRR) in the ground plane. By adding a slot in the middle, the rectangular patch becomes a U-shaped one which is responsible for the enhancement of antenna bandwidth and gain. Our antenna provides a bandwidth of 392 MHz which is about 2.7 times larger compared to that of a Conventional Microstrip Patch Antenna (CMPA) of the same dimension. The maximum gain of our antenna is found 6.56 dB which is around 2 dB higher than that of the conventional one (4.72 dB). Due to the addition of the CSRR array in the ground plane, an improved impedance matching of 50 ohms has been achieved. The operating frequency range of the PMPA is from 5.525 to 5.917 GHz which can be used for 5G applications such as Wi-fi, Wi-Max, and IoT devices in the U-NII band.

DESIGN OF DUAL BAND PATCH ANTENNA AT KU-BAND FOR WIRELESS APPLICATIONS

In this paper, U-shaped patch antenna with triangular stub antenna is proposed for satellite and radar applications. The U-shaped with triangular stub structure is considered on the patch antenna with symmetric feed is presented on the substrate. The antenna design is impressed on FR4_Epoxy substrate material whose dielectric constant is 4.4. The adopted antenna resonates dual band frequencies at 14.1049GHz and 15.1610GHz which are used for satellite communications and 16.9363GHz and 17.7903 GHz which are used for radar communications. The parameters of antenna like gain, reflection coefficient, radiation pattern and bandwidth are analyzed and presented in the results. The adopted design achieves gain of 5.18dB and reflection coefficient of -28.75dB at 14.1049GHz, gain of 3.79dB and reflection coefficient of -16.31dB at 15.1610GHz, gain of 3.40dB and reflection coefficient of -16.45dB at 16.9363GHz and gain of 4.17dB and reflection coefficient of -15.93dB at 17.7903GHz.

Intelligent Antenna System for Medical Applications

In this paper, we present U-shaped patch antenna with meander slot. The objective of the proposed antenna is for biomedical application. The operating frequency of the proposed antenna is 2.45 GHz. The designed antenna is of compact size of 35*25*1.5 mm3 with FR4 substrate which is possible by meandered slot. It is demonstrated that the antenna with meandered slots reveals low return loss at perfect resonant frequency which is suitable for bio medical applications. The bio medical application needs compact size of the antenna, which is attained by placing meandered slots above the surface of the radiating patch. The antenna simulation is carried out by advanced design system simulator.

Dual‐band dual‐polarized compact planar monopole antenna for wide axial ratio bandwidth application

In this article, a geometrically simple, microstrip line-fed planar monopole structure with slanting edge ground plane is designed to realize the dual-band dual-polarized operation. The proposed antenna consists of a rotated U-shaped patch and an electromagnetically coupled L-shaped parasitic radiating element. Owing to the combination of microstrip line-fed radiating patch and a slanting-edge rectangular ground plane on the opposite side of the substrate, the proposed dual-band antenna can generate broad axial ratio bandwidth (ARBW) in the upper frequency band. The overall dimension of the prototype is only 32 × 32 × 1.6 mm3. The measured results validate that the proposed antenna has two operational frequency bands, 29.84% (1.54-2.08 GHz) for linearly polarized radiation and 71.85% (3.96-8.4 GHz) for circularly polarized radiation. Measured result shows that 3-dB ARBW of the proposed antenna is 73.54% (3.80-8.22 GHz) in the higher frequency band. It shows that the higher frequency band exhibits a left-hand circularly polarized radiation in the boresight direction.

Design & analysis of a dual-band MIMO antenna to reduce the mutual coupling

A compact dual wide-band multiple-input-multiple-output (MIMO) radiator is presented in this article. The MIMO radiator is developed on a 1.5 mm thick FR-4 substrate. The proposed structure is composed of U-shaped patches which are connected with small rectangular slit loaded circular rings and partial ground plane with chamfer edges. This arrangement is placed symmetrically at a far distance of 2.5 mm to achieve dual-operating bands with a high amount of isolation, radiation efficiencies and group delay between two radiators. The proposed compact dual-band radiator is resonating at 2.5/6.4 GHz frequencies and it provides isolation greater than 20 dB over the operating bands. The proposed design has a size of 0.45 λ0 × 0.291 λ0 × 0.03λ0 mm and |S11| of about 41.25 dB and 14.58 dB. This design has a wide impedance matching in the range of frequencies from 2.38 GHz to 3.17 GHz & 5.14 GHz to 7.39 GHz with |S21| < 15 dB. The performance of diversity is calculated through diversity gain (DG) higher than 9.99, and Envelope Correlation Coefficient (ECC) which is less than 0.04 over the operating bands.

A Compact Microstrip Antenna With Enhanced Bandwidth and Ultra-Wideband Harmonic Suppression

A compact microstrip antenna with enhanced bandwidth and ultra-wideband harmonic suppression is presented in this communication. To broaden the working bandwidth of dipole antenna, U-shaped patch, slender stub, and parasitic patch are applied. To improve the bandwidth of the harmonic suppression, slender stub, parasitic patch, short stub, and U-shaped slot are introduced. The proposed antenna has a wide impedance bandwidth and an ultra-wideband harmonic suppression without extra circuit. In the end, a model antenna with the center frequency 4.3 GHz (f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">C</sub> ) is designed and manufactured. The proposed antenna has a fractional bandwidth of 42.8% (3.43-5.3 GHz) and a wide harmonic suppression bandwidth range from 1.4fC to 6.0f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">C</sub> (6.2-26 GHz).

Design of a miniaturised broadband 3 × 3 mm antenna for intraocular retinal prosthesis application

A highly compact and broadband antenna suitable for a prosthetic device to restore vision in the blind is presented. By embedding three straight sections of meandered microstrip patch line at the feed point, the proposed antenna gives three separate bands at 2.45, 4.2, and 5.8 GHz. The square patch loop is etched in the centre for miniaturisation. Three U-shaped patch stubs are utilised for frequency tuning. Three bands are merged together by adopting two square annular rings in the ground to obtain a wider bandwidth (2–8 GHz) incorporating unlicensed industrial, scientific and medical (ISM) and UWB bands.

A new group of species within the bee genus Ruizantheda, with a revised key to the males of the genus (Hymenoptera: Halictidae: Caenohalictini).

Males of the neotropical bee genus Ruizantheda Moure sensu lato (Halictinae: Caenohalictini) differ from those of other caenohalictine genera in having the outer gonostylar plate with a large membranous region that extends to the ventral region, and the ventral gonostylar lobe retrorse. These features permit the placement of six additional species described here, four of which are new, in the genus in this broader sense. The males of these six species share the following characteristics: profemur swollen; mesofemur exceedingly swollen; mesotibia slightly swollen with flat, minutely ridged ventral area and small apical tooth; S4 shortened medially, commonly largely hidden under S3, with transverse median depression and apical margin emarginate; apicolateral lobes of S4 with tuft of branched setae and stout, simple, recurved setae on margin; S5 with U-shaped gradulus and setal patch, sometimes inconspicuous; outer lateral expansion of penis valve bilobed, and median posterior margin of volsella strongly angulate. Together, these species constitute a new group within Ruizantheda and share with the previously known Ruizantheda inca Coelho, Felizardo, Engel, R. aerugineus Coelho, Felizardo, Engel, and R. kallos Coelho, Felizardo, Engel, a short outer gonostylar plate, terminating before the apex of the main gonostylar lobe as well as the presence of long setae on its dorsal surface. In other species of Ruizantheda the outer gonostylar plate extends beyond the apex of the main gonostylar lobe and lacks setae. The species comprising this distinctive subgroup of Ruizantheda, and treated herein, are: R. nigra n. sp., R. colombiana n. sp., R. venezuelana n. sp., R. baeri (Vachal) n. comb., R. pilosa n. sp., and R. gaullei (Vachal) n. comb. Two of the new species expand the distribution of the genus northward into Colombia and Venezuela. In addition to the description and illustration of the species, an updated key to the species of Ruizantheda s. l. is provided.

Study and design of U-shaped patch antenna for multiband application

Recent mobile technologies require slimmer mobile phones to furnish several frequency bands with minimal number of installed antenna. Therefore, in this paper, U-shaped patch antenna for multiband is proposed, designed and analyzed. Despite using more than one antenna, only one antenna is sufficient to resonate at several frequencies. The proposed antenna resonates at three different frequencies which are 2.9 GHz, 3.8 GHz and 4.8 GHz with optimum gains of 1.36 dBi, 1.23 dBi and 0.98 dBi respectively. The antenna was designed and simulated using in CST software.