Slot In Ground Plane Research Articles

Analytic Radiation Models of a Microstrip Line on a Slotted Ground Plane

In this Letter, analytic models for EM radiation analysis of a microstrip line (trace) on a slotted ground plane are proposed. The EM radiation is separated by the effects of trace and slot, and analytic radiation models for each effect are presented. The radiated electric field in the far region is calculated at a frequency up to 10 GHz, and the effect of the slot size on the radiation is examined. The proposed models are in good agreement with the numerical results while requiring a negligible computation time.

A triple band pattern reconfigurable planar antenna for 5G applications

Abstract This paper presents a triple-band planar antenna with diverse radiation patterns. The proposed planar antenna is a modified swastika shape with three fingers and the ground plane is a circle with rectangular slots etched on four sides radially. The slotted ground plane is loaded with Four PIN diodes to realign the surface current. Pattern reconfigurability is achieved at the triple bands by changing the states of the diode. The antenna operates in triple bands centered at 2.2, 2.9 and 3.5 GHz. The antenna is printed on FR4 Epoxy substrate. The simulated reflection coefficient is well below −10dB at resonant frequencies. The measured patterns and return loss are in very close agreement with the simulated results. This antenna can find potential applications in 5G systems.

Optimized Super-Wideband MIMO Antenna with High Isolation for IoT Applications.

A compact, low profile, multiple-input–multiple-output (MIMO) diversity antenna with super-wideband (SWB) characteristics has been proposed. The proposed antenna comprises four symmetric monopole-radiating elements printed on low-cost FR4 substrate with the slotted ground plane. The single antenna of a monopole structure and a quad-port MIMO antenna, with the dimensions of 30 × 20 mm2 and 60 × 55 mm2, respectively, are ideal for IoT and high-speed data applications. The proposed MIMO antenna has a high diversity gain and low envelope correlation coefficient (ECC) within the frequency range. Simulated results demonstrate the performance of the MIMO-SWB antenna, which operates from 2.3 to 23 GHz, with a high isolation level over 20 dB in the achieved frequency band. Moreover, the proposed MIMO antenna has been investigated with mirror fashion and orthogonal structure. Both structures provide similar results except for mutual coupling performance. The orthogonal adjustment for high isolation achieves better results with the proposed model. Further, the prototype of the proposed antenna is fabricated and measured effectively. Simulated and measured results show good agreement for super-wideband applications.

Development of deeply focused microwave lens applicator for efficient hyperthermia treatment

In this paper, a deeply focused microwave lens applicator is investigated for hyperthermia treatment. The lens applicator consists of a double spiral antenna (DSA) and frequency selective surface (FSS) as superstrate. The double spiral structure is designed on the top of the upper substrate (Substrate-1), the slotted ground plane is placed between the upper and lower substrate (Substrate-2), and the microstrip feed line is printed on the bottom of the lower substrate. The overall size of the proposed antenna is 32 × 32 × 3.27 mm3. Moreover, an FSS structure (as superstrate) is designed, which has a size of 64 × 64 mm2 (consists of a 4 × 4 unit cell). The FSS structure behaves as a lens that converts the bidirectional field pattern of DSA into the unidirectional pattern, which improves the focusing ability of the proposed applicator towards the phantom. The lens applicator is simulated with heterogeneous phantom (layers of skin, fat, and muscles), and the performance of the applicator is evaluated in terms of specific absorption rate (SAR), penetration depth (PD), and effective field size (EFS). The lens applicator is fabricated and experimentally validated in the presence of an artificial phantom. The measured results are in close agreement with the simulated one. Further, the performance of the applicator is analyzed for a deeply placed irregular-shaped tumor (at 15 mm from the skin surface). The study of temperature distribution is done, and the peak value of temperature is obtained as 43 °C with 2.5 W of microwave power given to the antenna. The temperature value around the tumor is obtained in the range of 41–45 °C, which is suitable for effective hyperthermia treatment.

Wideband Three Loop Element Antenna Array for Future 5G mmwave Devices

In this work, a compact, light-weight, low-cost, and easy install and incorporate mmwave printed square loop antenna with a perturbed ground plane is proposed. The antenna is fabricated on an ultra-thin 0.254 mm Rogers RT/Duroid 5880 substrate. The antenna resonates between 26 GHz and 40 GHz providing the broad bandwidth of 13 GHz ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sim 47$ </tex-math></inline-formula> %). First, a single element consisting of three rectangular square loops and a transmission line with total dimensions of 9 mm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times11$ </tex-math></inline-formula> mm ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.84\,\,\lambda _{0} \times 1\,\,\lambda _{0}$ </tex-math></inline-formula> ) is designed. The loop elements are arranged on top of each other and with the further insertion of square slot in ground plane, wideband resonance response has been achieved. The antenna demonstrates gain of more than 3.3 dBi, and radiation and a total efficiency of 98% at 28 GHz. The proposed design enables spatial diversity and minimize the effects of interference between adjacent channels by providing dual-beam within desired frequency band. In addition, a linear array ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$18.5\times22.5$ </tex-math></inline-formula> mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ) of four elements with a traditional feeding network is also designed, simulated, and measured. The gain of the array is 10.1 dBi, while the radiation and the total efficiency is more than 92 % at 28 GHz. A brief literature review and comparison of this work with other published works is also presented. To validate the proposed design and concept, a prototype is fabricated for both, a single element, and an array. It is found that the measured results and the computed results are in good agreement. Therefore, we believe that this system will find its applications within modern mmwave communication cellular devices.

A Modified SWB Hexagonal Fractal Spatial Diversity Antenna With High Isolation Using Meander Line Approach

This manuscript introduces a novel miniaturized super wideband (SWB) hexagonal fractal spatial diversity 2-element multiple-input-multiple-output (MIMO) antenna for broadband applications, as a compact wideband antenna is required for military radio and space communication devices. The designed antenna includes two hexagonal ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1^{st}$ </tex-math></inline-formula> modified Koch iteration) Koch fractal radiators with two linear tapered feedlines (TLTF) and a step tapered slotted ground plane (STSGP) that provides the broad impedance characteristic with miniaturized size in the operating band of 1.78-30 GHz. Moreover, the STSGP is also accountable for enabling the isolation ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$S_{12/21}$ </tex-math></inline-formula> ) better than 10 dB. To further meet the isolation higher than 22 dB, a meander line is protruded from the ground plane while maintaining a 6 mm edge-to-edge distance between two antenna elements. Typically, the MIMO antenna with high isolation is beneficial for high-speed data transmission. The experimental outcomes represent that the proposed MIMO antenna is with the advantages of reasonably good diversity gain (nearly 10 dB), stable radiation patterns, high peak gain (almost 6.6 dBi), and moderate radiation efficiency (around 85%) across -10 dB impedance bandwidth. The total active reflection coefficient (TARC) and envelop correlation coefficient (ECC) are less than −25 dB and 0.1 respectively. Due to all these attributes, the proposed 2-element MIMO antenna array can be a potential candidate for military radio, spectrum sensing for cognitive radio, and space communication applications.

A Pentagonal Shaped Microstrip Planar Antenna with Defected Ground Structure for Ultrawideband Applications

A new compact pentagonal microstrip patch antenna with slotted ground plane structure, developed for use in ultrawideband applications, is studied in this article. The proposed antenna is mainly constituted by a pentagonal shaped patch antenna, a defected ground plane structure, two stubs, and four slots to improve the bandwidth. The designed antenna has an overall dimension of 30 × 17.59 × 1.6 mm3, for WIMAX/WLAN/WiFi/HIPERLAN-2 /Bluetooth/LTE/5G applications with a very large bandwidth starting from 2.66 to 10.82 GHz (S11 < − 6 dB). A parametric study of the ground plane structure was carried out to find the final and the optimal UWB antenna, and to confirm that the antenna has good performance and broader bandwidth. The proposed antenna prototype has been fabricated. The measured results indicate that the antenna has a good impedance matching. The antenna has an electrically small dimension with a good gain, a notable efficiency, and a wide impedance bandwidth, which makes this antenna an excellent candidate for ultrawideband wireless communication, microwave imaging, radar applications, and the major part of the mobile phone frequencies as well.

Novel 2 × 2 square slot circularly polarized antenna array with wideband characteristics

In this paper, a novel 2 × 2 square slot wideband circularly polarized antenna array (CPAA) is proposed. The antenna consists of a sequential rotation feeding structure, four asymmetric U-shaped feeding strips and a slotted ground plane formed by four square slots with cut corners, four rectangular slots, and four L-shaped strips. In contrast to the traditional L-shaped feeding strips used in CPAAs, an asymmetric U-shaped feeding strip is, for the first time, presented to improve the antenna performance. By using these strips and slots as perturbation elements, the slotted CPAA is able to stimulate multiple circular polarized (CP) radiation modes, resulting in wideband CP radiation. The measured results revealed that the 3-dB axial-ratio (AR) bandwidth for AR < 3 reached 81.3% (1.75–4.15 GHz), whereas the −10-dB impedance bandwidth (|S11| < −10 dB) reached 88.6% (1.96–5.08 GHz).

A compact ultra-wideband square and circular slot ground plane planar antenna with a modified circular patch

Abstract A compact ultra-wideband (UWB) square and circular slot ground plane planar antenna with a modified circular patch for UWB communication is presented. This antenna has a low reflection coefficient and high gain in the range of 8.94 GHz, starting from 2.85 to 11.79 GHz. The proposed antenna demonstrates UWB behavior with electrically small dimensions of 0.18 λ0×0.14 λ0×0.015 λ0 (λ0 is the free-space wavelength at 2.85 GHz). The fractional bandwidth of the antenna is 122.1%, with stable radiations. The antenna's maximum gain stands at 2.79 dBi, and the antenna's peak efficiency stands at 72%, respectively. It is lightweight, compact, and easy to manufacture. Hence, it can be used for the complete range of UWB applications and covers Wi-Max/WLAN/ X-Band and Ku-Band.

A double hollow rectangular‐shaped patch and with the slotted ground plane monopole wideband antenna for microwave head imaging applications

SummaryThis paper introduces a lightweight wideband planar antenna with an antenna array configuration for microwave head imaging. The designed antenna is composed of a double hollow rectangular‐shaped patch and with the slotted ground. Its measurements are small: 0.28λ × 0.24λ × 0.006λ, where λ is the lowest operating frequency's wavelength. The design process has been completed using CST and then fine‐tune the parameters of the architecture structure to accomplish the ideal bandwidth. The antenna is manufactured and measured in order to test antenna properties. The prototype was being used for brain screening than with the Hugo‐head model. With adequate impedance matching, the antenna meets an operational bandwidth of 1.82 GHz (1.22–3.04 GHz) with an overall peak gain of 5 dBi with a stable radiation property. Fidelity factors both for face‐to‐face and side by side alignment are 92.7% and 83.75%, respectively, indicating that the antenna had a little signal interruption. To determine the backscattered signals of the antenna with Hugo‐head phantom, a nine‐antenna array‐based setup is assumed, with one antenna serving as a transmitter and the remaining eight receiving the dispersed signals.

PATCH AND GROUND PLANE SLOTS EFFECT ON THE RECTANGULAR PATCH MICROSTRIP UWB ANTENNA BANDWIDTH PERFORMANCE

In this paper, the impact of patch and ground plane slots on the bandwidth performance of a microstrip UWB antenna is presented. Our reference antenna is a microstrip feeding type monopole feature with a rectangular patch and a partial ground plane. In order to evaluate the characteristics of the reference antenna bandwidth, two separate slot types (right-angle triangular and rectangular) have been inserted into the patch and a single slot configuration like a rectangular is also inserted into the partial ground plane on the backside of the feed line to the appropriate. The influence on the bandwidth characteristics of single and multiple slot cases is analyzed using the HFSS simulator. Based on the slot configurations, the simulation results verify that the antenna bandwidth can be improved.

A novel antipodal tapered slot antenna integrated with half mode substrate integrated waveguide‐based bandpass filter for K and Ka band applications

AbstractIn this article, we present a novel half mode substrate integrated waveguide (HMSIW)‐based bandpass filter fed antipodal tapered slot antenna. We employ a novel feed consisting of three horizontal slots with two gaps arranged periodically on the top metal layer of HMSIW to obtain |S11|&lt;‐10 dB and |S21|≃0 dB over the passband from 21.6 to 40 GHz. We incorporate sinusoidal corrugations at the antenna outer edges along with ground plane slots. We control the operating bandwidth of the antenna over 21.6–40 GHz with |S11|&lt;‐10 dB using the proposed feed. The antenna offers gain of 10–12.44 dB and stable radiation pattern over the controlled band. The proposed antenna, 16 × 30.3 × 0.254 mm3 in volume, is fabricated and tested for validation. The measurement results show good agreement with simulations. The proposed antenna compares favorably with the state‐of‐the‐art. It is compact and exhibits stable gain and stable radiation pattern over the controlled bandwidth.

A compact inexpensive UWB-modified elliptic antenna including a slotted ground plane for an indoor positioning system

Within the present article, an original inexpensive UWB-modified elliptic antenna including slots in its ground plane is presented. This antenna with the FR4-epoxy substrate has a very modest size of 21 × 24 × 1.6mm3. The measured results confirm that the suggested antenna has an impedance bandwidth (|S11|< − 10 dB) of 134.13%, which expands from 3.1 to 15.72 GHz, covering the entire UWB frequency range and reaching a maximum gain of approximately 9.5 dBi at 14 GHz with an average value equal to 3.3 dBi throughout the functional frequency band and a maximum radiation efficiency of 97% obtained for the frequency 8.3 GHz with an average value equal to 94% over the whole frequency band. Excellent accordance between the simulation and measurement is observed. This antenna presents an approximately omni-directional radiation diagram in some directions, a dipole-like radiation pattern at lower frequencies and a quasi-stable group delay through the operating band, making the antenna relevant for most useful UWB applications, especially for indoor localization. Impedance matching is performed by employing two ellipses with diverse semi-major axes ″a″ as radiating patches and by optimizing the size, number, and position of the inserted slots in the downsized ground plane. Detailed information on the simulation and experimental results is provided and discussed.

Electrically Tunable Left-Handed Textile Metamaterial for Microwave Applications.

An electrically tunable, textile-based metamaterial (MTM) is presented in this work. The proposed MTM unit cell consists of a decagonal-shaped split-ring resonator and a slotted ground plane integrated with RF varactor diodes. The characteristics of the proposed MTM were first studied independently using a single unit cell, prior to different array combinations consisting of 1 × 2, 2 × 1, and 2 × 2 unit cells. Experimental validation was conducted for the fabricated 2 × 2 unit cell array format. The proposed tunable MTM array exhibits tunable left-handed characteristics for both simulation and measurement from 2.71 to 5.51 GHz and provides a tunable transmission coefficient of the MTM. Besides the left-handed properties within the frequency of interest (from 1 to 15 GHz), the proposed MTM also exhibits negative permittivity and permeability from 8.54 to 10.82 GHz and from 10.6 to 13.78 GHz, respectively. The proposed tunable MTM could operate in a dynamic mode using a feedback system for different microwave wearable applications.

Single‐fed dual wideband filtenna for 4G / 5G mobile applications

This article presents a single-fed single-layer dual-band slotted antenna which has the ability to simultaneously operate at microwave and millimeter-wave (MMW) frequency bands. It consists of a rectangular slotted ground plane, double cascaded tuning stubs, and embedded MMW element of L-shape inside the slotted ground. Ultra-wideband bandstop filter (BSF) is inserted at the feeding for isolating the two operational bands. The BSF consists of 3-open circuited stubs and in-line coupled line section. For demonstration, a design prototype of the complete integrated filtenna is fabricated and measured. Good agreements between simulated and measured results are observed. The proposed filtenna operates at 5.2 and 28 GHz with impedance bandwidth (15.23% and 17.03%) and the gain reaches (4.09 and 6.18 dBi).

A Dual-Band Modified Franklin mm-Wave Antenna for 5G Wireless Applications

Franklin array antennas are considered as one of the most competitive candidates for millimeter-wave (mmW) 5G applications due to their compact size, simple geometry and high gain. This paper describes a microstrip Franklin antenna array for fifth generation (5G) wireless applications. The proposed modified Franklin array is based on a collinear array structure with the objective of achieving broad bandwidth, high directivity, and dual-band operation at 22.7 and 34.9 GHz. The designed antenna consists of a 3 × 3 array patch element as the radiating part and a 3 × 3 slotted ground plane operating at a multiband resonance in the mmW range. The dimensions of the patch antennas are designed based on λ/2 of the second resonant frequency. The designed antenna shows dual band operation with a total impedance bandwidth ranging from 21.5 to 24.3 GHz (fractional bandwidth of 12.2%) at the first band and from 33.9 to 36 GHz (fractional bandwidth of 6%) at the second band in simulation. In measurement, the impedance bandwidth ranges from 21.5 to 24.5 GHz (fractional bandwidth of 13%) at the first band and from 34.3 to 36.2 GHz (fractional bandwidth of 5.3%) at the second band, respectively. The performance of the antenna is analyzed by parametric analysis by modifying various parameters of the antenna. All the necessary simulations are carried out using HFSS v.14.0.

Narrowband aperture coupled waveguide to microstrip transition for space applications

Background/Objectives: To design, analyze and fabricate aperture coupled waveguide to microstrip transition for Ka-Band where energy is coupled through slot in ground plane and a metal patch placed over the substrate. Methods: Impedance matching approach has been adopted for transition design. Microstrip line is inserted into the waveguide through aperture acting as a probe. Followed by inductive line and transformer line for impedance translation between waveguide and microstrip line. Waveguide transition has been designed using Ansoft High Frequency Structure Simulator (HFSS) full-wave EM simulator. Findings: Designed transition shows return loss performance better than 15 dB and insertion loss better than 0.5 dB for back to back configuration over a frequency band of 34 – 36 GHz. Transition is fabricated on RT5580 Duroid substrate (2r= 2:2) with substrate thickness 0.254 mm. Measured results show return loss better than 25 dB and insertion loss less than 1 dB over a frequency band of 34-36 GHz. Table 2 shows comparison of present design with previously reported designs in terms of performance. Novelty/Applications: Comparison of the presented transition shows superior performance to previously reported transition designs in terms of transition bandwidth and insertion loss. Aperture coupled transitions can be widely used for space applications where hermetic sealing is required and it saves extra effort for sealing. Certain RF circuit applications require narrowband waveguide transitions to attain required performance, in this case aperture coupled transition can be a good option and its integration with RF circuits is also easy. Fabricated transition design results show good agreement with simulated results so it can be concluded that design is tolerant to fabrication errors. Transition has been fabricated using standard PCB process so production of such transition can be done easily without requirement of any special facility for fabrication. Keywords: Aperture coupled transition; waveguide; microstrip; kaBand;hermetically sealed

A frequency reconfigurable microstrip antenna based on graphene in Terahertz Regime

In this paper, a frequency reconfigurable THz antenna is presented. The antenna is a microstrip antenna including a rectangular patch and a slotted ground plane. To realize frequency reconfigurable antenna in THz band, graphene is used instead of PIN diodes. The antenna is enable to work in different modes by changing the parameters of graphene. This ability can replace ON or OFF state of the diode. By working in these different modes, the operation frequency of the proposed antenna changes from 2.8 to 4.2 THz. Suitable radiation patterns, wide impedance bandwidth more than 10%, a good impedance matching, and an average gain of 2dB are achieved throughout the most the antenna’s operation states.

Bandwidth Enhancement Technique of a Dual-Band Circularly Polarized Dielectric Resonator Antenna

This paper presents the rectangular aperture coupled dielectric resonator antenna with dual-band circularly polarized response. The antenna geometry have stair case shaped rectangular dielectric resonator in the form of main radiating element. The specific geometry provides increment of aspect ratio of the dielectric resonator. This allows merging of various resonant frequencies having higher order modes that result in the bandwidth enhancement. This antenna provides 18.63% and 7.68% of -10 dB S11-parameter bandwidth response in operating passbands, respectively. The specific geometry and the introduction of circular slots in ground plane results in the orthogonal modes excitation at the nearby resonant frequencies. Due to this, the circular polarization response at 7.76 and 8.33 GHz frequencies is achieved. The peak gain of 5.8 and 4.6 dBic is obtained in the respective lower and upper operating passbands. Through parametric analysis, tuning of antenna responseis also achieved. The proposed antenna with the optimized parameters may have potential applications in the microwave C- and X-band setups.

Design and Analysis of Dual Frequency Microwave Moisture Sensor Based On Rectangular Microstrip Antenna

The two proposed design microstrip patch antenna as a sensor are analysed with the help of CST software for detecting the moisture. The proposed design is T-Shape rectangular shape with slotted in the ground plane and without slotted in the ground plane. It is operated at two frequencies 2.2GHz and 4.6GHz. It is designed on FR4 substrate and thickness is 1.676mm. The moisture can be detected with the help of oven drying technique. It will be helpful for measuring the moisture content. This technique is very easy, less time consuming, versatile and compact. The ground parameter of the proposed design is 20mm, as well as the length and width of the patch dimensions are 15mm and 10mm, which will be very portable. The designs is simulated on CST software and gets the good return loss, which is -16dB at 2.2GHz and -45dB at 4.6GHz. The gain is also the important parameter of the sensor; the proposed slotted ground plane design gain is 4.99dB at 4.6GHz as well as without slotted ground plane design gain is 5.1dB at 4.6GHz. It will be fabricated and measure the moisture in rice grains with the help of vector network analyser. The calibration equation and regression equation is also the important role of detecting the moisture content.