Low-profile Patch Antenna Research Articles

TRIPLE-BAND CIRCULAR PATCH MICROSTRIP ANTENNA FOR WIRELESS COMMUNICATION

In this article, a triple-band patch antenna using a circular patch microstrip antenna is constructed with a low-profile patch antenna using a 1.5 mm thick FR4 substrate (εr= 4.3). As mobile devices like smartphones and laptops become more common, the usage of tiny, triple-band antennas has also become more common. The objective of this research is to design a circular patch antenna with a 3–11 GHz dipole-like radiation pattern, which may be used for industrial, scientific, and medical reasons. For the suggested triple-band antenna design, the slotted radiator with six arches and the reduction of the ground plane are among the components. In addition, the standard 50 Ω RF transmission line stimulates the patch antenna; this transmission line is attached to the microstrip line by an impedance-compliant SMA connection. Data from the experiments are obtained, evaluated, and compared; to the patch's surface current distributions, gain, and radiation patterns. According to the measurements, S11 has an impedance bandwidth in the 5.5 GHz band of less than -10 dB, 6.6 GHz band, and 10.4 GHz band at all frequencies. The superb radiation pattern performance, relatively consistent gain throughout the bands, and practical bandwidths of this antenna make it a good choice for C-band and dual X-band applications.

A Dual-Polarized Differential-Fed Low-Profile Patch Antenna With Improved Bandwidth and Gain Selectivity

A Dual-Polarized Differential-Fed Low-Profile Patch Antenna With Improved Bandwidth and Gain Selectivity

A Single Plane Low profile Patch Antenna π-Shaped Slots and Low Side Lobe Level for Directive Wireless Communications

The patch antenna was used recently for ISM band (5.725 – 5.875) GHz, the patch antenna suffers of being an antenna with low gain as well as narrow operating bandwidth with high side lobe level (SSL) radiation pattern. A single plane with low profile and easy fabrication microstrip patch antenna has been proposed in this work was presented for directive communications and operates in Industrial, Scientific, and Medical (ISM) band 5.8 GHz with low SLL radiation pattern and gain of 5.20 dB for pint to point (directive). The gain of antenna has been increased while SLL decreased due to shifting the radiating patch and feeder of antenna with specific distance toward –ve side of the X-axis without any need for using techniques which would increase overall dimensions of antenna. The antenna has been printed on Arlon AD 250 substrate. The simulated results of antenna’s gain, operating frequency, bandwidth, return loss, and radiation pattern are presented. CST Microwave studio software was used in this design simulation.

Design of Microstrip Patch Antenna for 5G Communications

Abstract: This project aims to design and implement a low-profile patch antenna for 5G communication application. The resonating frequency has been chosen as 3.5 GHz for 5G application. Rogers RT5880 (lossy) epoxy material with permittivity of 2.2 has been chosen for the substrate material which has fire redundant property. The size of the substrate is 60×60 mm. The proposed antenna is compact Star-Shape radiating patch with defected ground structure, and the feeding technique is used as strip line feed. This proposed Star-Shaped antenna has been designed, analyzed and simulated by CST microwave studio, an electromagnetic simulation software. Antenna parameters like S-Parameter, Antenna Gain, Directivity, Efficiency has been observed and tabulated the results. This proposed Star-Shape antenna is widely used for 5G mobile communication applications.

Wideband E-shaped Patch Antennas for Advanced Wireless Terminals

Low-profile patch antennas have become ubiquitous in wireless terminals, especially as devices have become smaller and demand more functionality out of their RF subsystems. While their shape and size is attactive for many applications, their narrow bandwidth hinders their usage in many systems. With the rise of computer-aided design, many patch antenna design concepts have been presented with enhanced bandwidth capabilities. The E-shaped patch antenna, whose original shape presented in the early 2000’s resembles the letter E, offers compelling performance with reasonable manufacturing complexity. In it most basic form, this antenna was linearly polarized and either wideband or dual-band. Over the last two decades, many variations of the E-shaped patch have been presented in literature: circularly polarized, miniaturized, frequency reconfigurable, or even polarization reconfigurable. This paper summarizes these efforts in realizing novel functionalities with a relatively simple design geometry.

Low-Profile Patch Antenna Pair With Pattern Diversity Using Common and Differential Modes for MIMO Systems

We propose a low-profile hexagonal patch antenna pair with pattern diversity by using a single shared radiator. More specifically, both equivalent circuit and full wave simulation results show that the common mode and the differential mode of the grounded hexagonal patch could be excited with similar resonant frequencies, and then the coupling-feed method is employed to extend the impedance bandwidth. Simulation and measurement results demonstrate that such antenna pair, featuring a better decoupling performance, could be capable of generating both of the apple-shaped radiation pattern and the broadside radiation pattern in a wide band with the shared patch size of 0.2 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$ \lambda _{0}$</tex-math></inline-formula> <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$ \times\, 0.37\, \lambda _{0}$</tex-math></inline-formula> and the profile height of 0.05 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$ \lambda _{0}$</tex-math></inline-formula> . The proposed design should pave the way for the development of more compact multiple-input–multiple-output (MIMO) systems.

Low Profile Dynamic Patch Antenna Array With High-Intensity Radiation Fields (HIRF) Protection

A 1-bit low-profile patch antenna array integrating beam scanning and adaptive high-intensity radiation fields (HIRF) protection is proposed in this paper. Each antenna element consists of two dielectric layers, two radiation patches, a ground plane, and a feeding network. By electronically controlling a pair of coding diodes in the same direction, the antenna element can achieve 180 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^\circ$</tex-math></inline-formula> phase difference, producing two logical states, namely “0” and “1”. It has good beam scanning capability in the range of −60 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^\circ$</tex-math></inline-formula> to 60 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^\circ$</tex-math></inline-formula> . When the proposed antenna is exposed to HIRF, the protective diodes mounted over the grounded coplanar waveguide (GCPW) transmission line are triggered, dramatically reducing the overall gain of the antenna array. By optimizing design, the element possesses a bandwidth of 8.8 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\sim$</tex-math></inline-formula> 9.3 GHz. The grating lobe of the antenna array is suppressed by 17.5 dB thanks to the adoption of the non-uniform feed. The simulation results indicate that the proposed antenna element and array have a high isolation degree of 22.4 dB and 23.2 dB when exposed to HIRF, respectively. Finally, a prototype of the antenna is fabricated, and the validity of the proposed design is experimentally verified. The experimental results are in good agreement with the simulation results, demonstrating the validity of the proposed design.

Circularly Polarized Miniaturized Implantable Antenna for Leadless Pacemaker Devices

A compact circularly polarized (CP) implantable antenna working at 915 MHz, at the industrial, scientific, and medical (ISM) band, is developed in this article. The proposed radiator is based on a fully planar and low-profile patch antenna with a ground plane and different slots but without any via holes, which makes the structure a good candidate for implantable devices. The circular polarization is achieved by means of introducing a surrounding and asymmetrical U-shaped structure. A meander line has been included in the inside of the U-shaped structure to increase the electrical length of the antenna without increasing its mechanical dimensions. An impedance bandwidth of 18.9% from 810 to 980 MHz and an axial ratio of 17.2% from 850 to 1010 MHz have been achieved. The proposed antenna has a compact size of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$5.2\times 5.6\times0.25$ </tex-math></inline-formula> mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> , which seems to be the smallest antenna over the recently reported implantable antennas. In addition, the proposed antenna achieves a relatively high gain value of −23 dBi.

Triband Microstrip Rectangular Patch Antenna for Bluetooth/WiFi Applications

In recent years, according to the requirements of wireless applications, multiband and low profile patch antennas are desired. In this study, a simple rectangular patch triband microstrip antenna is developed to use for Bluetooth/WiFi applications. The antenna is in the form of rectangular slots with different lengths loaded on the rectangular patch with reduced ground size. FR-4 substrate with 1.6 mm thickness is used as substrate material and annealed copper is used as ground and patch materials. The designed antenna is simulated using CST MWS software program. Microstrip line feeding technique with discrete port is used to feed the antenna. According to the results, S11 parameters of three resonant frequencies can be given as -15.08 dB, -11.88 dB and -24.03 dB at 2.39 GHz, 3.07 GHz and 4.92 GHz respectively. Gain values of the resonance frequencies can be given as follows, 2.25 dBi, 3.76 dBi and 1.92 dBi at 2.39 GHz, 3.07 GHz and 4.92 GHz respectively. Proposed antenna bandwidth can be given as, 197.5 MHz (2.29 GHz – 2.49 GHz) at 2.39 GHz, 116.1 MHz (3.01 GHz – 3.13 GHz) at 3.07 GHz and 266.2 MHz (4.79 GHz – 5.06 GHz) at 4.92 GHz, respectively. Since the designed antenna can work at 2.4 GHz and 5 GHz frequency bands with 2.24 dBi and 2.34 dBi, respectively, IEEE 802.11ac/b/g standards are supported by the antenna. So the proposed antenna can be used for Bluetooth and 2.4 GHz/5GHz WiFi applications.

An All-Textile Dual-Band Antenna for BLE and LoRa Wireless Communications

In this paper, a dual-band conductive textile-based wearable antenna operating at LoRa-868 MHz and BLE-2.4 GHz is presented. The proposed antenna is intended for accurate geolocation, tracking and communication applications in the military, industrial and telemedicine industries. The low-profile patch antenna is suitable for integrating into clothing. It is composed of three textile layers: top and bottom silver-ink-printed polystyrene fabrics, and a neoprene substrate. To utilize the flexible and restorable properties of these textile materials, the proposed antenna is directly fed by a flexible cable using an aperture-coupled feeding technique. This method not only eliminates the use of the conventional, bulky, and metallic SMA connector but also introduces a secondary resonance at 2.4 GHz, enabling the dual-band property. Using a thin coaxial cable fixed on the aperture slot for proximity coupling, a compact antenna size of 150 mm2 is obtained that can easily be attached and detached on existing cloths. The proposed structure has been fabricated and measured in an anechoic chamber to verify the performance. Measured gain of 3.28 dBi and 3.25 dBi was realized for LoRa and BLE at an antenna size of 0.61 λg × 0.61 λg × 0.012 λg (where λg is guided wavelength at 868 MHz) with a front-to-back ratio (FBR) of greater than 10 dBi.

An end-fire low profile patch antenna to work on WiMAX frequencies used for harvesting power supply

In this paper, an end-fire microstrip patch antenna (MPA) is proposed of 3 GHz as a center frequency, designed, simulated, and measured to work on WiMAX frequencies within standard of 802.16e (WiMAX). A high gain ranged between (12.117-13.324) dB, high front to back ratio (F/B) of (35.770) at the center frequency, a wide band of 1.701 GHz, low profile, and semi-ideal voltage standing wave ratio (VSWR) of 1.053 is achieved. The simulation is done using computer simulation technology (CST-MW). The proposed design is based on two Fire-retardant substrates (FR-4) of relative permittivity (ε) 4.3+j0.025 and 1.53 mm thickness for each one, which is considered a high loss material. The measurement results show good agreement with the simulated results. In addition, the design can be used for harvesting power supply from mobile towers. Finally, the proposed design is compared with two other designs in terms of power conversion efficiency and overall size.

무선전력전송용 고지향성 Low-Profile 패치 안테나 설계

In this study, we propose a high-directivity low-profile patch antenna for microwave wireless power transmission systems. The proposed antenna is analyzed according to fundamental and higher-order modes based on the cavity theory, and high-directivity characteristics are derived with an optimum patch size using the directivity formula. To achieve low-profile characteristics, a high-directivity patch antenna is designed by applying the optimum permittivity, which can simplify the structure and lower the manufacturing cost. For a side length of 0.63λ0 and substrate permittivity of 5.4, a maximum directivity of 11.4 dBi is observed. The measured and simulated reflection coefficients are −12 dB and −12.7 dB at 5.8 GHz, respectively, and the bore-sight gains are 8.5 dBi and 10.1 dBi at 5.8 GHz, respectively.

A New β-shaped Microstrip Patch for Bluetooth

This paper introduced the design of a low-profile patch antenna. The demonstrated antenna can be used for Bluetooth application. At 2.4GHz the antenna has good properties. The antenna is built on flame resistant (FR4) substrate with a total size of 110mmx 110mm. To comprehend the resonant performance of the antenna a parametric analysis is performed by changing the radiating length and circular slot radius of β shaped antenna.

High-gain low-profile circularly polarized patch antenna for universal RFID reader application

It is known that for a microstrip antenna, if the height of the antenna is strictly limited, then the bandwidth is narrow. A way to solve this problem is to combine two modes. However, for almost all the two-mode resonant patch antennas reported, the height of the antenna conflicts with the frequency ratio of the two modes. The smaller the frequency ratio is, the higher the antenna. In this paper, a detailed mode analysis is performed, and a comprehensive mode shift design method is established. A dual resonant patch antenna with any frequency ratio can be designed. Guided by this method, a low-profile wideband patch antenna with a size of only 0.6λ0 × 0.6λ0 × 0.05λ0 for the universal RFID reader (840-960 MHz) is designed. The simulated and measured results show that a low-profile is achieved for universal RFID reader antennas.

High-Resolution Dielectric Constant Measurement Using a Sensor Antenna With an Allocated Link for Data Transmission

A dual-band low-profile patch antenna, which operates based on aperture-coupling mechanism, is exploited to measure the permittivity of a sample under test (SUT) in the microwave frequencies and send the measured data simultaneously. The upper resonant frequency, which is considerably affected by changing the permittivity of the SUT, can be utilized for sensing purpose. In contrast, the lower resonant frequency is almost independent of the samples hence can be used as the communication link. The samples are placed on top of the feeding side of the structure. The variation in the sample’s permittivity leads to changes in the input impedance of the sensor antenna. While this change results in having different feedline-dependent resonant frequencies, the cavity-dependent resonant frequency is almost preserved intact for different samples. The sensor antenna is designed using electromagnetic solver and an equivalent circuit is proposed to model its behavior. The effect of varying parameters in the equivalent model is investigated. Moreover, by fabricating the sensor, the measurement results show that by changing the permittivity of samples from 1 to 12.85, the upper band resonant frequency (feedline-dependent) shifts from 12.30 to 11.37 GHz (78 MHz per unit dielectric constant). Nevertheless, the small variation in resonant frequency and radiation characteristics of the antenna in the lower band (cavity-dependent) can provide a stable communication channel with respect to the SUT. This link with a reasonable 2.8% (9.54-9.81 GHz) 10-dB impedance bandwidth can be reserved for sending the measured and pilot data in a wireless sensor system.

Compact Patch Antenna With Vertical Polarization and Omnidirectional Radiation Characteristics

This communication proposes a compact, low-profile patch antenna with omnidirectional radiation pattern and vertical polarization. A pair of shorted patches are excited in-phase to achieve the omnidirectivity and the vertical polarization, simultaneously. The principle is to excite two back-to-back arranged shorted patches to generate symmetrical electric-field (E-field) distributions normal to the ground plane. Analytical study on how to generate the omnidirectional radiation pattern is carried out. Based on this study, we found that the spacing in between the two patches have little influence on the radiation characteristics, which provides another flexibility in the design. In addition, the shape of the patch and the corresponding field distribution are investigated to further improve the omnidirectivity. To improve the impedance bandwidth, resonant structures are inserted in between the patches, producing the second-order response in frequency. The antenna has been fabricated and characterized, and the measured results are in reasonable agreement with the simulations, showing that the proposed antenna is suitable for potential surface-mount wireless applications.

High-gain low-profile rectangular microstrip patch antenna with Yagi elements

ABSTRACT This paper presents a novel high gain rectangular microstrip patch antenna (RMSA) with vertically placed Yagi elements. The antenna is fed by a coaxial probe to excite TM01 fundamental waves at 2.4GHz, which is suitable for wireless local area network (WLAN) applications. In order to increase the antenna gain, Yagi elements are placed in groups of 5, on each side of the substrate in order to serveas directors for the radiating slots as well as the ground reflections. The proposed antenna offers 1.3dB gain improvement and %3 .1 impedance bandwidth increase in comparison to the plain rectangular microstrip antenna with the same specifications. The advantage of this antenna is to provide an easy and cost effective solution to increase microstrip antenna gain, particularly in 8-10dB range, without disruptingits planar structure.

Characterization of extremely low profile patch antenna loaded with periodic diamond metasurface ground plane

AbstractThe characterization of an extremely low profile patch antenna is studied which is loaded with periodic diamond metasurface ground plane. Compared with conventional patch antenna, the new antenna has a smaller patch size, increased bandwidth, and enhanced efficiency. These performances are numerically investigated and optimized. By loading an optimal metasurface structure, a particular patch antenna is demonstrated in experiments. Measured results show that the metasurface antenna is in extremely low profile of 0.0045λ0. The patch length is 0.245λ0 or 0.36λg which is far beyond the 0.5λg limitation associated with a conventional prototype. In addition, the metasurface antenna has an impedance bandwidth of 1.83% and radiation efficiency of 83% in measurement. These two parameters are observed to be limited at level of 0.69% and 69%, respectively for a conventional patch antenna.

RT/Duroid 5880-based Hook slotted multi frequency low profile patch antenna for WBAN applications

A triple band RT/Duroid 5880-based hook slotted Antenna for Wireless Body Area Network (WBAN) is investigated in this paper. This antenna can be used for On-body and Off-body communication; it provides wireless link between the wearable devices on the body and away from the body for WBAN users like patients, sports persons, soldiers and firefighters. The fabricated Low profile Patch antenna operates in RF Band, ISM Band and C Band in 1.87 GHz (Upper), 2.45 GHz (Lower) and 5.71 GHz (Upper) respectively. The hook slot designed on the patch antenna is used to improve the performance of antenna in view of WBAN applications. The proposed antenna is fabricated using RT/Duroid 5880 of permittivity 2.25 and tangent delta 0.0004 which is viable to use in wearable and On-body communications. Analysis of the proposed antenna is done by Simulation and fabrication results and their comparison. The low profile antenna performs maximum reflection coefficient value −25.73 dB, directivity 2.86 dBi, 3.39 dBi and 4.59 dBi at 1.8 GHz, 2.45 GHz and 5 GHz respectively, maximum gain 2.85 dB and 1.67 w/Kg SAR levels over 1 g of mass average.

A Design of Low Profile Microstrip Patch Antenna With Bandwidth Enhancement

It is known that for a microstrip antenna (patch antenna) resonant in a single mode, if the height of the antenna is strictly limited, the bandwidth is narrow, and the performance at the side frequencies is worse than that at the centre frequency. A way to solve this problem is to combine two modes into one single narrow band. However, almost all the two-mode resonance methods reported are for wideband patch antennas because the frequency ratio of two bands is commonly large and hard to decrease. In this article, a detailed mode analysis based on transmission line theory is performed, and a mode shift theory is established for patch antennas. A dual-mode patch antenna with any frequency ratio can be designed. Guided by this theory, a low-profile patch antenna with a size of only $0.23\lambda _{0}\times 0.23\lambda _{0}\times 0.027\lambda _{0}$ ( $\lambda _{0}$ is the wavelength of the centre frequency in free space) for the Beidou BD3 band (1.258 GHz-1.278 GHz) is designed. The antenna resonates in two modes, and the frequency ratio is only 1.02. The simulated and measured results show that the gain performance of the proposed antenna is almost flat over the operating band (3 dBic-3.1 dBic), which is hard to achieve through any other bandwidth enhancement method.