Maximum Antenna Gain Research Articles

<inline-formula> <tex-math notation="LaTeX">$E$ </tex-math> </inline-formula>-Band Substrate Integrated Waveguide Orthomode Transducer Integrated With Dual-Polarized Horn Antenna

This paper presents an E-band substrate integrated waveguide (SIW) dual-polarized antenna system, which consists of an orthomode transducer (OMT) and a dual-polarized horn antenna. On the basis of a two-layer substrate design, the function of OMT is realized by utilizing an SIW section to excite TE10 mode for the vertical polarization, a quasi-coaxial stripline to excite quasi-TEM mode for the horizontal polarization. And also, a slot line transition is placed at the common port of the two structures for impedance matching with the ridge SIW dual-polarized horn antenna. In this way, the dual-polarized horn antenna is designed with an exponential ridge structure simultaneously for better impedance matching and higher efficiency of the antenna. To verify the functionality of the proposed integrated OMT-antenna structure, an experimental prototype is fabricated and measured, and a good agreement is found between its simulation and measured results. Over the frequency range of 83–87 GHz, return loss better than 10 dB at all ports and cross-polarization less than −25 dB are obtained. The maximum antenna gain is about 14 dBi for the horizontal polarization and 15.2 dBi for the vertical polarization. It is believed that the proposed OMT-antenna design is suitable for ultrahigh capacity millimeter-wave backhaul applications in future wireless communication systems.

Broadband single‐layer reflectarray antenna for X‐band applications

A new type of X-band (8-12 GHz) unit cell structure on a single-layer for broadband reflectarray antennas is presented in this study. To obtain a broadband performance, a unit cell composed of a circular ring and a complementary diagonal patch ring is proposed. This new type unit cell is designed on a 0.183 × λ 0 (air-dielectric) thin dielectric substrate and has a 430 ° phasing range with slow phase variation. Based on the wide phase variation of the proposed unit cell, a centre-fed broadband reflectarray antenna is designed with 9 × 9 unit cells, 81 elements on a square plane geometry. The designed reflectarray has 40% aperture efficiency and 96% antenna efficiency at 10.5 GHz. The validity of the reflectarray antenna is verified through measurement and simulation results. The experimental and simulation results are in good harmony. The measured and simulated results show that the maximum gain of the reflectarray antenna is 21.6 dBi at 10.5 GHz and has 23% 1 dB gain bandwidth and 29% 3- dB gain bandwidth. Also, the minimum cross-polarisation discrimination is 31.2 dB at 11 GHz frequency.

C-Band Active-Antenna Design for Effective Integration With a GaN Amplifier

This paper aims to effectively integrate a GaN amplifier into a high-efficiency active-antenna design. In this paper, the antenna is designed for a GaN high-electron-mobility-transistor (HEMT) impedances calculated by a load–pull simulation with a GaN nonlinear model, which contributes to a lossless design and prevents power-added-efficiency (PAE) reduction by active-antenna integration. The antenna impedance is selected to reduce the impedance-transform ratio with the GaN HEMT. In addition, the active antenna includes a second-harmonic-tuning circuit for high efficiency. The active antenna comprises antenna- and amplifier-circuit layers piled onto a Peltier unit, which has a high affinity with this cooling systems. The antenna and amplifier circuits are designed on low- and high-dielectric substrates, respectively, enabling the amplifier to be downsized and the antenna gain to be increased. Each layer is connected by a through-hole. First, the single-stage amplifier is fabricated with a maximum output power of 37.95 dBm and a maximum PAE of 62.94%. Next, the GaN active antenna is fabricated with a maximum effective isotropically radiated power of 44.61 dBm and a maximum antenna gain of 23.99 dBi. The assumed amplifier large-signal characteristics of the active antenna agree with those of the single-stage amplifier. Therefore, the amplifier and the antenna are integrated without loss.

The Gain Estimation of a Fabry-Perot Cavity (FPC) Antenna with a Finite Dimension

In this paper, we have presented an equation for estimating the gain of a Fabry-Perot cavity (FPC) antenna with a finite dimension. When an FPC antenna has an infinite dimension and its height is half of a wavelength, the maximum gain of that FPC antenna can be obtained theoretically. If the FPC ant...

Lens Antenna for Wide Angle Beam Scanning at 79 GHz for Automotive Short Range Radar Applications

This communication presents the design and experimental verification of a substrate integrated waveguide fed lens antenna for 79 GHz automotive radar applications. The proposed integrated lens antenna consists of a six layer cylindrical Luneburg lens illuminated by 17 source elements of substrate integrated waveguide fed by a planar log periodic dipole antenna array. The Luneburg lens is developed by using a unique foam material AirexR82 ( $\varepsilon _{r} = 1.12$ ), which is drilled and pressed to achieve the different dielectric constant needed to follow the index law inside the lens. The return loss and the radiation characteristics of the proposed integrated lens antenna are investigated and validated by measurements. A good agreement between the measured and simulated results is observed. The measured results confirm the beam scanning capability of the proposed integrated lens antenna for a wide scan angle of ±85° in azimuth plane having a maximum antenna gain of 15 dBi at 82.5 GHz and gain drop of less than 2.75 dB for the edge feeds. The estimated radiation efficiency of the antenna is found to be 67% at 82.5 GHz.

CPW-Fed Wideband Circular Polarized Antenna for UHF RFID Applications

We propose a wide bandwidth antenna with a circular polarization for universal Ultra High Frequency (UHF) radio-frequency identification (RFID) reader applications. To achieve a wide 3 dB axial ratio (AR) bandwidth, three T-shaped microstrip lines are inserted into the ground plane. The measured impedance bandwidth of the proposed antenna is 480 MHz and extends from 660 to 1080 MHz, and the 3 dB AR bandwidth is 350 MHz and extends from 800 to 1155 MHz. The radiation pattern is a bidirectional pattern with a maximum antenna gain of 3.67 dBi. The overall size of the proposed antenna is 114 × 114 × 0.8 mm3.

Graphene-Flakes Printed Wideband Elliptical Dipole Antenna for Low-Cost Wireless Communications Applications

This letter presents the design, manufacturing and operational performance of a graphene-flakes based screenprinted wideband elliptical dipole antenna operating from 2 GHz up to 5 GHz for low cost wireless communications applications. To investigate radio frequency (RF) conductivity of the printed graphene, a coplanar waveguide (CPW) test structure was designed, fabricated and tested in the frequency range from 1 GHz to 20 GHz. Antenna and CPW were screen-printed on Kapton substrates using a graphene paste formulated with a graphene to binder ratio of 1:2. A combination of thermal treatment and subsequent compression rolling is utilized to further decrease the sheet resistance for printed graphene structures, ultimately reaching 4 Ohm/sq. at 10 {\mu}m thicknesses. For the graphene-flakes printed antenna an antenna efficiency of 60% is obtained. The measured maximum antenna gain is 2.3 dBi at 4.8 GHz. Thus the graphene-flakes printed antenna adds a total loss of only 3.1 dB to an RF link when compared to the same structure screen-printed for reference with a commercial silver ink. This shows that the electrical performance of screen-printed graphene flakes, which also does not degrade after repeated bending, is suitable for realizing low-cost wearable RF wireless communication devices.

A Novel Substrate Integrated Suspended Line Wideband Leaky-Wave Antenna

A novel compact wideband leaky-wave antenna based on substrate integrated suspended line is proposed. The proposed antenna is designed to be self-packaged format with five substrate layers and embedded air cavities. Asymmetric feeding is utilized to excite the first higher order mode. In order to achieve the suppression of backlobe and impedance matching, the tapered radiator with an etched slot is introduced. According to the measured results, the maximum antenna gain of 15.1 dBi and 50% fractional bandwidth from 7.5 to 12.5 GHz are obtained. Additionally, the self-packaged antenna has good radiation properties with low backlobe and sidelobe. The scanning angle of the measured main beam is about 44° ranging from 10° to 54°.

A miniaturized UWB via‐less CRLH‐TL loaded CPW FED patch antenna

ABSTRACTA novel miniaturized ultra‐wide band (UWB) via–less composite right hand left hand transmission line (VL‐CRLH TL) loaded‐coplanar waveguide (CPW) fed monopole antenna has been designed. The CRLH unit cell has been realized with series capacitance and parallel inductance and implemented with gap capacitance and meander line inductance respectively. The meander line inductance is grounded using CPW ground through rectangular stub which eliminates conventional CRLH TL metallic via into ground plane. The proposed antenna is constructed of two unit cells fed by a CPW feed. The offset of feed location attached to patch is more important for impedance matching between them and proposed optimum feed location offset lof = 0.6 mm, which eliminates additional quarter wave transformer to impedance match. The total compact antenna dimension is 25 × 15 × 1.6 mm3 or 0.12λ0 × 0.07λ0 × 0.008λ0, where λ0 is free‐space wavelength at 1.55 GHz. It covers the impedance bandwidth (S11< −10dB) of 1.55 GHz – 14.25 GHz, which corresponds to 160% of fractional bandwidth. The minimum and maximum gain of antenna are 1 dBi at 1.55 GHz and 3.5 dBi at 8.4 GHz respectively, which is suitable for UWB applications. The parametric study of antenna has been done using CST microwave studio and a prototype of the antenna with FR4 substrate is fabricated and tested. Good agreement between simulated and measured results. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:2485–2492, 2016

Investigation and design of an ultra-wideband fractal ring antenna for notch applications

In this article, an ultra wideband ring antenna with a fractal formation for notch application is presented. The antenna was printed on FR-4 substrate, which was a low cost one with the relative permittivity of 4.4 and thickness of 1.6 mm. The total dimension of antenna was 50 mm × 50 mm. It could be applied as a notch antenna for propagation rejection in IEEE 802.11a for instance by covering were as without conflicting with wireless systems. The prototype antenna presented in this article, has a rejection band at 5–6 GHz and covers the frequency range of 2.1–11 GHz with the VSWR of less than 2. For improvement of the notch frequencies and for obtaining dual notch band characteristic some changes in prototype antenna with a slot at fractal structure have been performed. The final antenna had dual notch band at 2.5 and 5.5 GHz. The current distribution in the notch frequency has been provided. The efficiency has also been checked for the entire frequency band. The maximum antenna gain was achieved between 2–8 dBi. All the simulations were done in HFSS and compared with the experimental results. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:1629–1634, 2016

무선 DVI 동글장치를 위한 스파이럴 구조를 갖는 폴디드 모노폴 안테나에 관한 연구

In this paper, we proposes a internal antenna for wireless DVI dongle device using the folded monopole structure. The proposed antenna uses a basic structure of spiral and monopole. The antenna optimized for parameters length, gap, width, and rectangle of folded monopole antenna using the spiral structure. To confirm the characteristics of the antenna parameters, HFSS from ANSYS Inc. was used for the analysis. We used an FR4 dielectric substrate with a dielectric constant of 4.4. The DVI dongle size of the proposed antenna is , and the size of the antenna area is . There is a value of return loss less then -10dB in 2.4GHz and 5.8GHz, band and the maximum antenna gain is -4.13dBi. The utilization possibility of the wireless DVI Dongle antenna have a folded monopole with spiral shape could be confirmed according to compare and analyze the simulation and measurement data.

A Compact Dual-Polarized 3:1 Bandwidth Omnidirectional Array of Spiral Antennas

A circularly polarized wideband omnidirectional array of spiral antennas is presented. It covers the frequency band from 1.2 up to 3.6 GHz while keeping a good $S_{11}$ and an omnidirectional coverage. This array achieved a dual polarization using left- and right-hand Archimedean spiral antennas. The gain of the array is enhanced using a unique cavity for the entire array, and the realized gain is above the maximum theoretical gain of a single spiral antenna.

Triple-notch UWB monopole antenna with fractal Koch and T-shaped stub

In this study, a triple-notch ultra-wideband (UWB) monopole antenna with fractal Koch and T-shaped stub is presented. The prototype antenna is based on a circular monopole antenna with a back-plane feed line modified for 2–11GHz in an omnidirectional pattern. By implementing a combination of fractal Koch and T-shaped stub on the antenna, a triple-notch band occurred at 2, 3.5, and 5.8GHz for rejecting personal communication services (PCS), worldwide interoperability for microwave access (WiMAX), and wireless local area network (WLAN). In addition to the UWB application frequency range of 3.1–10.6GHz, the final antenna covers a frequency range of 1.78–1.91GHz for GSM 1800, 2.28–3.120GHz for Wi-Fi, and 2.4GHz for Bluetooth applications with a voltage standing wave ratio (VSWR)<2. Simulated results of HFSS and CST are compared with experimental results. The dimensions of the antenna are 50mm×50mm×1.6mm. The current distribution and efficiency at notch frequency are noted for the whole frequency band, and the maximum antenna gain is between −3.5 and 6.5dBi. In this study, methods using Koch structure and T-shaped stub to achieve triple-notch antenna are implemented in three steps. In addition, the effects of T-shaped stub and fractal Koch on the magnitude of the antenna (S11) are studied.

무선 HDMI 동글장치를 위한 폴디드 모노폴 안테나에 관한 연구

In this paper, we propose a internal antenna for wirless HDMI dongle device using the folded monopole structure. The proposed antenna is for 2.4GHz and 5.8GHz. The antenna optimized for parameters length, gap, width, and radius of semicircular of monopole antenna using the `F` structure. To confirm the characteristics of the antenna parameters, HFSS from ANSYS Inc. was used for the analysis. We used an FR4 dielectric substrate with a dielectric constant of 4.4. The HDMI dongle size of the proposed antenna is , and the size of the antenna area is . There is a value of return loss less then -10dB in 2.4GHz and 5.8GHz, band and the maximum antenna gain is -4.13dBi. The result proved the possibility of the practical using `F` structure that came frin comparing and analyzing the measured and simulated data of the antenna.

두 개의 팔을 가진 초광대역 자기상보형 시뉴어스 안테나

본 논문에서는 Cellular/GSM800, GSM900, ISM, GPS, DCS/GSM1800, PCS/GSM1900, WCDMA/UMTS/IMT2000, WiBro, WLAN, WiMax의 주파수 대역(0.824~5.85 GHz) 전체를 포함하는 초광대역 시뉴어스 안테나를 제안하였다. 제안한 시뉴어스 안테나는 두 개의 팔(arm)로 이루어져 있으며, 자기상보(self-complementary) 구조로 설계하여 주파수 무관 특성을 나타내도록 하였다. 안테나는 클로펜스타인 테이퍼(Klopfenstein taper) 구조의 광대역 발룬(balun)을 사용하여 <TEX>$50{\Omega}$</TEX>에 정합시켰다. 측정 결과, 제안한 안테나의 대역폭은 반사손실 -10 dB를 기준으로 할 때 0.76~6 GHz까지 5.24 GHz로, 목표 주파수 대역을 모두 포함하는 것을 확인하였다. 방사패턴은 E-plane과 H-plane 모두에서 전체 동작 주파수 대역에 걸쳐 거의 변화 없이 양방향성 브로드사이드 빔을 보였으며, 최대 이득은 2.32~6.01 dBi로 측정되었다. This paper presents a ultra-wideband sinuous antenna that operates in a whole frequency range (0.824~5.85 GHz) of Cellular/GSM-800, GSM900, ISM, GPS, DCS/GSM1800, PCS/GSM1900, WCDMA/UMTS/IMT2000, WiBro, WLAN and WiMax. The proposed antenna, which is composed of two sinuous arms, is designed as a self-complementary structure in order to have frequency-independent characteristics. It also uses a wideband balun of Klopfenstein taper structure to match to <TEX>$50{\Omega}$</TEX>. Experimental results show that the -10 dB return loss bandwidth of the proposed antenna is 5.24 GHz that ranges from 0.76 to 6 GHz, which covers all the frequency bands of the various wireless services. Within the entire operating frequency range, the measured radiation patterns in both E-plane and H-plane show nearly constant bidirectional broadside beams and the maximum antenna gain is measured to fall between 2.32~6.01 dBi.

Dual band antenna designing with composite right/left handed

ABSTRACTIn this article, dual band antenna by implementation of composite right/left‐handed for UWB and WLAN application is presented with L shape ground. First antenna, has two resonances at 1.8 and 5.2 GHz for GSM 1800 and 5 GHz WLAN indoor application with omnidirectional pattern and It is fabricated on FR‐4 low cost substrate with dielectric constant ε = 4.4 and loss tangent of tan δ = 0.02. In the second antenna, first band support 2.38–2.48 GHz that covers the WLAN with omnidirectional pattern but the second operation band is between 4.18 and 9.85 GHz for covering WLAN and at this frequency, antenna has semidirectional pattern. The second antenna is printed on Taconic TLY‐5 low permittivity substrate with relative permittivity of 2.2. Maximum antenna gain between −2 and 4 dBi but second antenna shows low gain and it is in range of 1.4–3.3 dBi. Albeit, here, the results of simulated antenna design are compared with experimental results. The current distribution shows that how these CRLH cells have helped for change in pattern of antenna. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:774–779, 2015

A COMPACT ANTENNA DESIGN FOR UHF RFID APPLICATIONS

This paper presents a new compact end-fire antenna for ultra-high frequency (UHF) radio frequency identification (RFID) applications. The antenna has two meandered dipole drivers. A folded reflector and a rectangular reflector are demonstrated. The advantage of the end-fire antenna with meander dipole drivers compared to the conventional quasi-Yagi antenna is a reduction in the length of the driver, which allows closer space for RFID reader. The end-fire antenna is fabricated on a FR4 printed circuit board (PCB), the dimension of the antenna is 81 × 58 mm 2 . The measured bandwidth is around 25 MHz (905-930 MHz) under the condition of VSWR less than 2. The maximum gain of the end-fire antenna is 3.5 dBi, it is suitable for fabrication on low-cost, low dielectric constant materials. The antenna configuration, design, simulated and measured results have been well discussed. A good agreement is obtained between the simulated and experimental results. This new compact end-fire antenna is desirable for RFID reader applications.

Miniaturization of Microstrip Antenna by CRLH-TL Technique

In this paper, an electrically small microstrip antenna has been presented by employing composite right/left-handed transmission line. The prototype antenna was designed by using Interdigital capacitor and spiral inductor. It is fabricated and printed on FR-4 low cost substrate with dielectric constant 4.4 and thickness 1.6 mm, Dimensions of antenna are $$15.5\,\hbox {mm}\times 12\,\hbox {mm}$$15.5mm×12mm. So, the size reduces about 69 % compared with conventional microstrip patch antennas at 1.8 GHz and more than 80 % for 1.1 GHz. Final model of the antenna has triple bands at 1,060, 1,800 and 2,500 MHz. Which two frequencies (1.8 and 2.5 GHz) are suitable for GMS and WLAN applications. The presented antenna is simulated in HFSS, Finally the simulated and experimental results are compared. The antenna has low gain so, it is suitable only for indoor and medical care applications which we need low power and low profile devices. The maximum gain of antenna at 2.4 GHz is around $$-$$-8 dBi that it is drawback of antenna, but it will sufficient for indoor and implant application such as health care. The antenna has an Omni directional pattern and a linear polarization.

IFA 구조를 이용한 소형 433MHz 안테나의 구현

Abstract In this paper, the antenna of a small active RFID for 433MHz is proposed, and the proposed antenna is a kind of built-in antenna, which uses IFA structure. The performance was improved by the change of the spacing between the feed point and short strip, inserting the meander line structure in a radiator, and varying the gap between the radiator and the ground plane in the proposed antenna. To confirm the characteristics of the antenna parameters, HFSS from ANSYS Inc. was used for the analysis. The frequency band of 433MHz Active RFID is from 433.67 to 434.17 MHz. There is a value of return loss less than –9.54 dB in 433MHz band of the active RFID, and the maximum antenna gain is -4.28dBi. The Jig size of the proposed antenna is 72 × 44 × 1mm, and the size of the antenna area is 35.5 × 19.5mm. The result proved the possibility of the practical use on miniaturized 433MHz antenna using IFA structure that came from comparing and analyzing the measured and simulated data of the antenna.

A Study on a Single Band Notch Characteristic of a UWB Planar Antenna with an Elliptical Element

UWB planar antenna comprising an elliptical element with a single band notch characteristic are studied and presented. A novel UWB planar antenna characteristic is compared with proposed design. Slanting slit is etched in the elliptical element. The slit is considered to generate the band notch characteristic. The elliptical element and ground plane are composed on top of the substrate. The band notch is characterized to eliminate the Wireless Local Area Network (WLAN). The proposed antenna maximum gain is better when compared with the novel UWB planar antenna. The radiation patterns are unchanged.