Antenna Size Research Articles

Sexual differences in size and chemical composition of antennae of American cockroach, Periplaneta americana (Dictyoptera, Blattodea)

Insect make use of their antennae for sensory purposes, in search for food, mating partners and any other necessary communications. In this study, sexual differences in the measurements and ionic concentration of the adult American cockroach, Periplaneta

Pattern Similarity and Gain Enhancement of Dual-Band Antenna Using an ENZ Metamaterial

A dual-band antenna with pattern similarity using the energy-squeezing mechanism of an epsilon-near-zero (ENZ) metamaterial is designed, and experimental results are presented with simulated data. To achieve high gain and pattern similarity, a waveguide-based ENZ metamaterial property is adopted in a planar microstrip form at the upper band. The designed dual-band antenna is resonating at 4.3 GHz and 9.8 GHz frequencies with the desired radiation pattern. A metamaterial unit cell with ENZ characteristics at 9.8 GHz is designed to improve the antenna’s performance. The permittivity and permeability of the unit cell are characterized using the Nicolson–Ross–Weir method. By adding a square ring structure, the antenna geometry exhibits ENZ characteristics. Using the ENZ material’s energy-squeezing mechanism, a 12-dB gain improvement is achieved in the upper band without affecting the lower band radiation characteristics without increasing the complexity. It can be used in C- and X-band applications, such as mobile, military, defense, and radar communication. The dual-band antenna with ENZ material is fabricated, and the measured results show a good match with the simulated results. The proposed antenna size at 4.3 GHz is 0.58λ × 0.58λ × 0.02λ.

Compact size antenna for skin implantable medical devices

Abstract This research work presents an implantable antenna that operates at 5.8 GHz. By using a radiator with a loop-based design, the antenna can be made smaller. Radiator is made up of three connected rectangular loops. On the substrate’s back side, an I-shaped ground plane is used. As substrate and superstrate, polydimethylsiloxane (PDMS) with dimensions of 7 mm × 5 mm × 0.3 mm is used. The conducting sections are made using copper foil that is 30 µm thick. The suggested antenna is examined by the implantable medical device using realistic human scalp phantom models and a homogenous skin box. Simulated study revealed that it operates around 5.8 GHz with a bandwidth from 5.69 to 5.92 GHz. The specific absorption rate was 0.28 and 0.26 W/kg for skin box and human scalp phantoms, respectively, at 1 mW input power across 1 g volume tissue.

Inset Fed Rectangular Patch Antenna Design for ISM Band Applications

Wireless communication systems rely on efficient and compact antennas to transmit and receive signals. Microstrip patch antennas have gained popularity due to their small size, low profile, and ease of fabrication. In this study, an inset fed microstrip rectangular patch antenna using a partial ground plane is designed for ISM band applications in the frequency range of 2.4 - 2.4835 GHz. The antenna is made on a low-cost FR4 substrate with a dielectric constant of 4.3 and a thickness of 1.6 mm. The dimensions of the antenna is 28.35 × 37.58 mm2. The antenna is fed by an inset feedline, which provides a compact and efficient feeding mechanism. The design of the antenna is carried out using CST Microwave Studio software. The performance of the antenna is evaluated based on various parameters such as return loss, bandwidth, VSWR, directivity, gain, and radiation pattern. The simulation results indicate that the proposed antenna achieves a return loss (S11) of -27.339 dB, a bandwidth of 0.01478 GHz (147.8 MHz), and a VSWR of 1.09. Additionally, the antenna provides a gain of 2.97 dBi, a directivity of 4.7 dBi, and an efficiency of -1.726 dB (67.20%). Overall, this design meets the requirements of decreased antenna size, lightweight, low profile, cost-effectiveness, simple manufacturing, and good performance for ISM band applications.

Miniaturization and Bandwidth Enhancement of Fractal-Structured Two-Arm Sinuous Antenna Using Gap Loading with Meandering

A sinuous antenna is a frequency-independent antenna known for its wide bandwidth and consistent gain, which makes it valuable in broadband applications such as ultrawideband (UWB) radar and ground-penetrating radar (GPR). However, sinuous antennas tend to be rather large. Consequently, numerous studies have explored miniaturization methods, with the gap-loading method emerging as a prominent approach. Unfortunately, it is still difficult to achieve broad bandwidths for conventional miniaturized sinuous antennas. In this paper, we use a novel approach incorporating a meander shape into the sinuous curve and employing gap loading with meandering. This innovative technique results in the development of a fractal-structured two-arm sinuous antenna characterized by an ultra-compact size and significantly expanded bandwidth. Adding a meander line in the outermost part maximizes the capacitance, thereby enhancing the gap-loading effect and minimizing the overall size of the sinuous antenna. In addition, the introduction of an inner meander line increases the inductance, contributing to a further expansion of the antenna’s bandwidth. For example, the electrical length of the antenna without the meander line is 0.552 × 0.552 × 0.052 λg3, while the electrical length of the antenna with the meander line is only 0.445 × 0.445 × 0.036 λg3, i.e., 19.4% smaller. The antenna lacking the outermost meander line exhibits a 10 dB impedance bandwidth, spanning from 0.74 to 10.53 GHz. In contrast, the antenna featuring the outermost meander line has a 10 dB impedance bandwidth, extending from 0.51 to 10.72 GHz, which results in a remarkable enhancement in the fractional bandwidth (by 8.1%). Hence, the proposed antenna design is a good candidate for broadband applications that require miniaturization.

Design of Multiband, Reconfigurable Coplanar Meander Antenna for WLAN Applications

This paper presents the implementation of Reconfigurable, Planar Meander Antenna operates at 2.45 GHz and 5.12 GHz for WLAN applications. In the proposed work the planar meander antenna is designed using FR4 substrate. In the meander antenna the varactor diodes are incorporated in the appropriate arm positions to achieve reconfigurability. In this, reconfigurability is accomplished using frequency tuning. Also, the principle of reconfigurability in meander antenna focuses size reduction and dual band operations. The meander structure is characterized for its operating frequency. A parametric study is done for finding the resonance in the appropriate arm positions of the meander antenna. The varactor diodes fixed meander antenna is tested using network analyzer. The comparison is made for the antenna designs of with and without varactor diodes for the establishment of reconfigurability. The effects of active components are ignored. The proposed antenna design is validated for its concurrence in both simulation and experimentation. The arm and the behavior of the frequency tuning is tested using the network analyzer. The reflection coefficient is -23.66dB and -18.41dB at 2.45 GHz and 5.1 GHz respectively. The overall size of the meander antenna is reduced by 76%. VSWR of the proposed antenna is 1.

Low-Loss Paper-Substrate Triple-Band-Frequency Reconfigurable Microstrip Antenna for Sub-7 GHz Applications.

In this paper, a low-cost resin-coated commercial-photo-paper substrate is used to design a printed reconfigurable multiband antenna. The two PIN diodes are used mainly to redistribute the surface current that provides reconfigurable properties to the proposed antenna. The antenna size of 40 mm × 40 mm × 0.44 mm with a partial ground, covers wireless and mobile bands ranging from 1.91 GHz to 6.75 GHz. The parametric analysis is performed to achieve optimized design parameters of the antenna. The U-shaped and C-shaped emitters are meant to function at 2.4 GHz and 5.9 GHz, respectively, while the primary emitter is designed to operate at 3.5 GHz. The proposed antenna achieved peak gain and radiation efficiency of 3.4 dBi and 90%, respectively. Simulated and measured results of the reflection coefficient, radiation pattern, gain, and efficiency show that the antenna design is in favorable agreement. Since the proposed antenna achieved wideband (1.91-6.75 GHz) using PIN diode configuration, using this technique the need for numerous electronic components to provide multiband frequency is avoided.

Design and Performance Analysis of Rectangular Microstrip Patch Antennas Using Different Feeding Techniques for 5G Applications

In this article, the design and performance of a novel rectangular microstrip patch antenna (RMPA) utilizing the dielectric substrate material FR4 of relative permittivity (Ԑr = 4.3) and thickness (h = 0.254 mm) is proposed to operate at (fr = 28 GHz). Three different feeding techniques (microstrip inset line, coaxial probe, and proximity coupled line) are investigated to improve the antenna radiation performance especially the antenna gain and bandwidth using Computer Simulation Technology (CST) and High Frequency Structure Simulator (HFSS). The simulated frequency responses generally reveal that the proximity-coupled fed provides extremely directive pattern and maintain higher radiation performance regardless of its antenna size which is larger than the other considered feeding ones. With the presence of the three feeding techniques, the gain is improved from 5.50 dB to 6.83 dB additionally, the antenna bandwidth is improved from 0.6 GHz to 3.60 GHz at fr = 28 GHz when the reflection coefficient S11= -10 dB. Compared to the previously designed RMPA, the proposed design has the advantages of reliable size, larger bandwidth and higher gain, which make it more suitable for many 5G application systems.

Interconnect for Dense Electronically Scanned Antenna Array Using High-Speed Vertical Connector.

We present the design and the performance evaluation of a new interconnect for large-scale densely packed electronically scanned antenna arrays that utilize a high-speed digital board-to-board vertical connector. The application targets microwave tissue, imaging in the frequency range from 3 GHz to 8 GHz. The tissue-imaging arrays consist of hundreds of active antenna elements, which require low-reflection, low-loss, and low-crosstalk connections to their respective receiving and transmitting circuits. The small antenna size and the high array density preclude the use of coaxial connectors, which are also expensive and mechanically unreliable. Modern board-to-board high-speed connectors promise bandwidths as high as 12 GHz, along with high pin density, mechanical robustness, and low cost. However, their compatibility with the various transmission lines leading to/from the miniature printed antenna elements and microwave circuitry is not well studied. Here, we focus on the design of the transitions from coplanar waveguide transmission lines to/from a high-speed vertical connector. The performance of the interconnect is examined through electromagnetic simulations and measurements. Comparison is carried out with the expensive sub-miniature push-on sub-micro coaxial connectors commonly used in miniature radio-frequency electronics. The results demonstrate that high-speed vertical connectors can provide comparable performance in the UWB frequency range.

An L-Slot Frequency Reconfigurable Antenna Based on MEMS Technology.

Given the shortage of spectrum resources and the demand for communication systems of diminutive size, multi-function, and adaptive characteristics, this paper proposes an L-slot frequency reconfigurable antenna based on the MEMS switch. The antenna size is 4.07 × 5.27 mm2 and is suitable for the U-band. The antenna structure consists of two RF MEMS switches, a Rogers RT5880 dielectric substrate, an L-slot patch, and a full-coverage ground. The switch is of a series contact structure and is arranged at the corner of an L-slot. By controlling the on and off state of the switch, the antenna can switch between four states of 42.36, 47.65, 53.13, and 56.72 GHz. According to the simulation results in CST STUDIO SUITE 2018, the maximum gain of the antenna is 7.90 dB, the impedance bandwidth of each state is above 1 GHz, and the direction is mainly consistent. The antenna can meet the demand for multi-frequency millimeter wave communication.

The role of the pigment-protein complex LHCBM1 in nonphotochemical quenching in Chlamydomonas reinhardtii.

Nonphotochemical quenching (NPQ) is the process that protects photosynthetic organisms from photodamage by dissipating the energy absorbed in excess as heat. In the model green alga Chlamydomonas reinhardtii, NPQ is abolished in the knock-out mutants of the pigment-protein complexes LHCSR3 and LHCBM1. However, while LHCSR3 is a pH sensor and switches to a quenched conformation at low pH, the role of LHCBM1 in NPQ has not been elucidated yet. In this work, we combined biochemical and physiological measurements to study short-term high-light acclimation of npq5, the mutant lacking LHCBM1. In low light in the absence of this complex, the antenna size of PSII was smaller than in its presence; this effect was marginal in high light (HL), implying that a reduction of the antenna was not responsible for the low NPQ. The mutant expressed LHCSR3 at the wild-type level in HL, indicating that the absence of this complex is also not the reason. Finally, NPQ remained low in the mutant even when the pH was artificially lowered to values that can switch LHCSR3 to the quenched conformation. We concluded that both LHCSR3 and LHCBM1 are required for the induction of NPQ and that LHCBM1 is the interacting partner of LHCSR3. This interaction can either enhance the quenching capacity of LHCSR3 or connect this complex with the PSII supercomplex.

A circularly polarised multiple input multiple output antenna with single‐sense for sub‐6 GHz 5G applications

AbstractIn this study, a compact wideband circularly polarised Multiple Input Multiple Output (MIMO) antenna with the two parasitic elements is proposed. The printed monopole antenna for wideband circular polarisation proposed in authors' previous study is used as an antenna element. One‐sided substrate reflector is installed at the back side of the antenna, positioned 0.2λ0 away, to improve the gain. The circularly polarised radiation, deteriorated by the influence of mutual coupling of two antenna elements and reflector, is improved by deploying two parasitic elements on the bottom layer of the antenna's substrate. The antenna's size is 0.99λ0 × 0.32λ0 and the reflector's size is 1.41λ0 × 0.82λ0 (λ0 is the free‐space wavelength at lowest operating frequency). The measured bandwidth of 10 dB impedance with a 3 dB axial ratio is 33.49% from 3.53 to 4.95 GHz, which can be utilised for sub‐6 GHz 5G applications. The simulated and experimental results are compared to validate the antenna characteristics.

A Triple-Band Broadband Miniature Antenna Design for Implantable Continuous Glucose Monitoring

This paper presents a miniaturized triband implantable planar antenna that covers the industrial, scientific, and medical (ISM) band and the Wireless Medical Telemetry Service (WMTS) band which can be used in a continuous blood glucose monitoring device. The antenna consists of a slotted radiating patch and a ground plane with a cross slot to miniaturize its size. The overall antenna size is only 51.35 mm3 (7.6 × 7.6 × 0.889 mm3) due to the reduced size by the slotting technique. Compared to other implantable antennas with similar performance, the proposed antenna is smaller in size, simple in construction, and easy to be fabricated. By cutting a cross slot in GND, impedance matching is improved, especially at the two higher frequency bands. We have fabricated the prototype and carried out measurements. The results show its gains are −32.2 dBi, −18.8 dBi, and −19.1 dBi at 0.9 GHz, 1.4 GHz, and 2.45 GHz, respectively. Its radiation patterns have good symmetry in the two lower operating frequency bands. In addition, the maximum SAR values comply with the IEEE standard safety guidelines (IEEE C95.1-2019).

Design of a Compact Microstrip Decoupled Array

A one-dimensional mono-pulse microstrip antenna plays an important role in target detection, tracking, recognition and imaging. However, feeding and coupling are the main reasons for the large size of the mono-pulse antenna, which is not conducive to miniaturization and integration. A miniaturized mono-pulse antenna is proposed to reduce the size and improve the integration in antenna design. The proposed antenna has a more compact size and good isolation, with a well-maintained radiation pattern and zero depth. The antenna unit size is 0.19 λ0 × 0.19 λ0 × 0.006 λ0. The overall antenna size is 78 mm × 78 mm × 1.48 mm (0.63 λ0 × 0.63 λ0 × 0.0012 λ0). In this communication, a general decoupling feeding network for two-element microstrip array antennas is also designed. Experiment validations confirm that the operating frequency of the designed antenna system is at 2.45 GHz with a gain of 5.54 dBi. The return loss of the sum and difference ports is 16.14 dB and 15.2 dB, respectively. The isolation of the ports is 36.6 dB. The proposed miniaturized mono-pulse antenna is approximately 64% smaller in size compared to previous versions.

Design and optimization of circularly polarized dielectric resonator antenna array based on Al2O3 ceramic

A comprehensive design of an ultra-broadband circularly polarized (CP) dielectric resonator antenna (DRA) array operating in the C-band for fifth-generation (5G) communication systems is presented in this paper. The objective is to achieve a compact antenna size capable of receiving and transmitting CP electromagnetic waves over a wider bandwidth. The material chosen for the dielectric resonator (DR) is Alumina (Al2O3) ceramic, known for its low dielectric loss and exceptional mechanical properties, making it an ideal candidate for the DR. The proposed design utilizes a 2 × 2 array of cross-shaped DRs, fed by a compact circular phase-shift feeding network with double-point feeding. This configuration results in a 3-dB axial ratio (AR) bandwidth of 48.7 % and an impedance matching bandwidth (IMB) of 53.2 %. The antenna's horizontal size is reduced to 1.17 × 1.17λ02, and the gain is significantly enhanced by exciting multiple Mie resonances in the stacked DRs, yielding a measured peak gain of 12.48 dBic. These outstanding features position the CP DRA array as an excellent choice for 5G communication systems.

Review on Patch Antennas for Unmanned Aerial Vehicle Application

The wide-ranging Unmanned Aerial Vehicle (UAV) applications making them be one of the Internet of Things promising technologies. The vast potential of monitoring and surveillance for public safety threats using drones be a current issue for researchers. Antennas play an important part in UAV to create reliable communication links. There are different types of antennas that can be used for UAV application depend on antennas size, efficiency, gain, angle of radiation pattern, polarization, etc. This paper mainly focuses on patch antennas for UAV applications. In general, there are two types of patch antenna is described which are single patch antenna and array antenna. The review of patch antennas can be a useful guideline to choose or design antenna for UAV applications in the future.

Design of compact low‐profile planar filtering antenna with enhanced suppression level

AbstractA compact low‐profile planar filtering antenna with an enhanced suppression level is presented in this paper. The presented antenna has a simple structure, consisting of an E‐shaped driving patch, a shorted parasitic patch, and a defected ground structure (DGS). The E‐shaped driving patch serves as an effective radiator and facilitates the filtering response. The shorted parasitic patch is horizontally arranged and coupled with the driving patch through the radiating edge. And a radiation null and an extra in‐band resonance can be generated, which would simultaneously broaden the impedance bandwidth and improve the suppression level. In addition, a DGS on the metalized ground plane is etched to introduce another radiation null, and the out‐of‐band suppression level would be significantly enhanced. The filtering antenna with a center frequency of 3 GHz was constructed and tested to verify its performance. The measured values, which indicate a bandwidth of 10% (2.85–3.15 GHz) and a peak realized gain of 5.2 dBi, are in agreement with the simulated values. The presented filtering antenna features a low profile of 0.016λ0, a compact antenna size of 0.16λ20, as well as an improved suppression level of more than 22 dB.

Unidirective Miniaturized Ultrawideband Antenna for Sensing Buried Objects in Handheld Ground-Penetrating Radar Systems: A design approach

Ground-penetrating radars (GPR) using ultrawideband (UWB) technology have attracted a lot of research interests worldwide for high-resolution sensing and material characterization. This research contribution, therefore, introduces a miniaturized lightweight UWB antenna with high-gain characteristics for applications in handheld GPR systems. The high-gain antenna is developed to function in the 3.13–11.74-GHz wide frequency range such that it can allow high-resolution sensing of buried targets, such as landmines, metal pipes, and other structures. An elliptical quadrant-shaped UWB monopole radiator with a protuberant ground plane is conceptualized to constitute a highly miniaturized antenna of size 18 × 11 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The standalone UWB antenna realizes an impedance bandwidth of 3.07–11.67 GHz with a peak gain of 2.9 dBi. Next, a single-side copper-coated dielectric substrate as a reflector is placed beneath the antenna to attain a significant gain improvement. The proposed design with a reflector provides an average gain improvement of about 7.1 dB without influencing the original bandwidth. For experimental validation, a prototype is fabricated and characterized. The measured performance reveals close agreement with the simulation with an operating bandwidth of 3.19–11.83 GHz and a maximum gain of approximately 10 dBi at 4.02 GHz.

A CPW‐fed fractal monopole antenna with a reduced ground plane in frequency range of 500 MHz‐5.5 GHz

AbstractIn this article, the authors propose a super wide band CPW‐fed fractal monopole antenna suitable for phased array antennas with a shaped beam radiation pattern, operating in the frequency ranges below and above 1 GHz at the same time. The antenna has an octagonal radiator with fractals of the same shape added to its edges and sides. Also, the symmetrical elliptical ground planes have reduced the antenna size and, consequently, the mutual coupling in the antenna array. Despite the super‐wide frequency range, the antenna's radiation pattern is relatively steady in the E‐plane, and the negligible ripple on the radiation pattern makes it suitable for shaped beam radiation patterns in phased array design. The single‐element antenna with an overall size of 0.24λ × 0.38λ at 500 MHz is printed on an FR‐4 substrate. The outcomes of the simulation and measurement are well agreed in the frequency band of [500 MHz to 5.5 GHz] with an impedance bandwidth (|S11|&lt; −10dB) of 166.67% and VSWR&lt; 2. Also, the fidelity factor of the antenna is studied to investigate the SWB performance.

Low-Cost L-Band to Ku-Band Frequency Reconfigurable BAR64-02V Controlled Antenna for Satellite, Military, and Radar Applications

A miniaturized edge-fed multi-band wideband (WB) sensor complementary split ring resonator (CSRR) and two folded pedal arms loaded antenna for wireless, ISM, military, Radar, and satellite applications is fabricated, tested, and investigated. The reduced ground plane at the bottom to makes the gain positive and leads to improvement in the radiation efficiency. Loading of antenna patch with two folded bicycle pedal-shaped arms results in an increased total electrical length and hence antenna could be tuned up to higher frequency bands. The appended two folded pedal arms enhance the value of gain and CSRR loading introduces additional resonant frequencies below −10dB reflection coefficient. The symmetrical ground width compression results in total antenna size miniaturization to 43.33% concerning the conventional circular microstrip antenna designed at a frequency of 2.45GHz. The antenna has a bidirectional radiation pattern with a gain of 5.21dBi and a radiation efficiency of 90.50%. The antenna exhibits four bands (2.13–2.58GHz), (2.77–3.89GHz), (5.65–6.56GHz), and (7.77–12.98GHz) within a frequency sweep of 1–15GHz, therefore it, is the most suitable element for Bluetooth, PCS, ISM band, 3G/4G/5G, Wi-MAX/WLAN/ Wi-Fi, and wireless, satellite, military, and RADAR applications. These bands are frequency reconfigured by two BAP64-02V PIN diodes in the pedal-arms fold locations with four switching combinations. The measured (frequency sweep: 1–23GHz) and simulated antenna reflection coefficient values are found in match except for a frequency range of 12–14 GHz. The antenna was fabricated on a low-cost FR-4 that holds well <12 GHz frequencies, and >12 GHz frequencies values this shows nonlinear and frequency dispersion.