Semicircular Slot Research Articles

Triple notched coplanar waveguide-fed novel ultrawide band antenna with time domain analysis

This research proposition introduces a novel microstrip antenna design that features triple notches for ultra-wideband (UWB) applications. The antenna, measuring 35.4 mm × 28.82 mm × 1.57 mm, incorporates rectangular and semi-circular slots, as well as a pentagonal stub. A modified U-shaped slot on the pentagonal stub creates one notched frequency band at 3.3–3.7 GHz. Additionally, two Split Ring Resonators (SRRs) are integrated into the antenna’s rear surface, resulting in two more notched bands at 5.1–5.8 GHz and 7.1–7.8 GHz. Operating within a frequency range from 3 to 11.2 GHz with VSWR ≤ 2, the antenna effectively excludes the triple stop bands at 3.3–3.7 GHz (11.4%), 5.1–5.8 GHz (12.8%) and 7.1–7.8 GHz (9.4%). The proposed antenna has been successfully prototyped and verified. An extensive result analysis has been conducted, confirming that the developed antenna is suitable for application in a range of wireless systems. Moreover, the article includes the implementation of an equivalent circuit for the proposed antenna.

An Innovative DGS Based Textile Antenna with Semi-Circular Slot for Future IoT’s and AI Applications

An Innovative DGS Based Textile Antenna with Semi-Circular Slot for Future IoT’s and AI Applications

Electromagnetic scattering from a truncated semicircular slot for TM mode

Electromagnetic scattering from a truncated semicircular slot for TM mode

Pattern Diversity Based Four-Element Dual-band MIMO Patch Antenna for 5G mmWave Communication Networks

This study presents a planar dual-band multiple-input multiple-output (MIMO) antenna design for the prospective fifth-generation (5G) frequency bands of 28 and 38 GHz. The antenna element is designed by utilizing a rectangular patch with an offset microstrip feeding technique. A dual-band response is achieved by placing semi-circular slots on each side of the patch element. To tune the frequency response and improve impedance matching, vertical rectangular slits are etched in the rectangular patch and the ground plane, respectively. The results show that the single antenna element offers an impedance bandwidth of 2.52 GHz (26.32–28.84 GHz) and 7.5 GHz (34–41.5 GHz). In addition, a MIMO configuration based on pattern diversity using four antenna elements is designed and fabricated. The designed MIMO configuration achieves an impedance bandwidth of 3 GHz (27–30 GHz) and 5.46 GHz (35.54–41 GHz) at operating bands of 28 and 38 GHz. The peak realized gain for the single element at 28 and 38 GHz is noted to be 7.4 dBi and 7.5 dBi, respectively. Furthermore, the polarization diversity configuration illustrates an isolation of > 15 dB and > 25 dB for the 28 and 38 GHz frequency bands, respectively. Moreover, the MIMO configuration attains appropriate values for the envelope correlation coefficient (ECC) and diversity gain (DG), Total Active Reflection Co-efficient (TARC), Channel Capacity Loss (CCL) and Mean Effective Gain (MEG) for the operating frequency bands. The proposed MIMO system based on results seems to be potential choice for mmwave Ka Band Applications.

CPW-Fed UWB-MIMO Antenna with Triple-band Notched and High Isolation using Double Y-shaped Decoupling Structure

A ultra-wideband (UWB) multiple-input-multiple-output (MIMO) antenna using double Y-shaped decoupling structure with high isolation and triple notched-band is presented. The designed antenna composed of two orthogonally placed monopole elements, coplanar ground and double Y-shaped branch. The defected substrate structure is used to achieve miniaturization. By slotting successively C-shaped slot, semi-circular slot and rectangular slot on the radiation patch and the ground, achieved three notched bands at 3.5 GHz WiMAX, 5.25 GHz WLAN, and 7.5 GHz X-band. The proposed antenna can operate in range of 2.56-12 GHz with triple notched bands of 3.31-3.96 GHz, 4.58-5.67 GHz and 6.57-8.16 GHz. Considering all the results, it can be concluded that the antenna presented has a great performance in terms of good radiation, high isolation (>24 dB), a low level ECC (<0.01) and a high DG level (>9.99), which proves the presented antenna has good prospect in UWB-MIMO systems.

Pattern Diversity Antenna for 5G-NR Application Based on Closely-Spaced Semi-Circular Slots

Pattern Diversity Antenna for 5G-NR Application Based on Closely-Spaced Semi-Circular Slots

Single iterated fractal inspired UWB antenna with reconfigurable notch bands for compact electronics

A simple, compact, and low-profile antenna operating over ultrawideband with high gain is presented in this manuscript. The antenna has dimensions of W × L = 19 mm × 21 mm and is placed on the rear side of the FR-4 substrate material. The antenna contains simple geometry, inspired from a circular fractals, which consists of a circular patch with a CPW feedline. The circular patch is loaded with two fractals patches at both top end of the substrate and the rectangular stub is loaded at the lower side, to improve the antenna's bandwidth. The constructed antenna offers a wide band of 3–13.5 GHz. The antenna geometry also contains three semicircular slots, which are etched to generate the notch bands. Each slot is etched step by step, giving notch bands at 3.9 GHz, 5.2 GHz, and 8.1 GHz. In the final stage, two diodes are added to attain reconfiguration. The antenna offers moderate gain and high radiation efficiency. The hardware model of antenna is engineered to verify the simulated results. Moreover, the antenna is compared with other works in literature. The outcomes of the proposed antenna and comparison with the literature work make the suggested work the best candidate for future UWB portable devices.

Non-conventional leather substrate based high isolation wideband MIMO antenna for body-centric applications

This work presents the design of a dual-port high isolation compact wideband wearable multiple-input multiple-output (MIMO) antenna employing a non-conventional leather substrate material. The designed antenna structure comprises defected structure at the ground plane, including two semicircular slots and two 'H' shaped stubs in the cascaded form to minimize the coupling effect between the antenna ports. The antenna works over the 2.22–8 GHz frequency range with a fractional bandwidth of 113.12 %, covering the application bands of WLAN (2.4–2.484 GHz), WiMAX (3.2–3.85 GHz), WLAN (5.15–5.35 GHz/5.725–5.825 GHz), C band downlink/uplink (3.7–4.2 GHz/5.925–6.425 GHz) and downlink defense (7.2–7.7 GHz) band. The suggested antenna provides port isolation above 27 dB, envelope correlation coefficient (ECC) under 0.09, diversity gain (DG) above 9.94 dB, channel capacity loss below 0.33 Bits/Sec/Hz, low magnitude ratio between mean effective gains of two ports (<0.1 dB), and a stable total active reflection (TARC) over the active spectral region. The designed antenna offers a SAR value less than the threshold level (<1.6 W/kg). The constructed MIMO antenna structure consumes a volume of 32 × 52 × 2 mm3.

Miniaturized dual wideband MIMO antenna for implantable biomedical applications

AbstractA novel miniaturized multiple input multiple output (MIMO)‐based implantable antenna is designed to operate with dual bands, which are wide enough to cover three industrial, scientific, and medical (ISM) bands of 402–405 MHz, 902–928 MHz, and 2.4–2.48 GHz. The proposed antenna has an overall dimension of π × × 0.635 mm3 and uses an RT3010 substrate of thickness 0.635 mm. Each element of MIMO has a spiral structure made of meandered line to realize resonance at 915 MHz, while an arc is etched in each element for obtaining a band of 403 MHz. Semicircular slots are etched in each quadrant of the ground plane for better impedance matching at the higher band of 2.4 GHz. In a −10 dB fractional bandwidth of 95%, 45.36% is attained for the realized bands. Simulation in a skin phantom provides better impedance matching and mutual coupling of less than −15 dB in the three operating bands.

SEMICIRCULAR SLOT BASED UWB MICROSTRIP PATCH ANTENNA FOR VARIABLE BAND NOTCHED APPLICATIONS

The patch antenna with Ultra-Wide Band (UWB) characteristics is a promising candidate for wireless communication. It is a major research problem to mitigate electromagnetic interference (EMI) with narrowband technologies such as 5G lower band, Wi-MAX, WLAN and satellite band, which are all in the UWB region. This study describes a UWB antenna with variable band rejection that can be used to avoid interference with Wi-MAX and 5G lower band applications. The UWB characteristics of a simple rectangle patch antenna with a faulty ground structure has been designed for operational bandwidth (2.7–13) GHz. A novel method semicircular slot (SCS) at the radiation patch creates a band notched from (3.25–3.80) GHz and (3.4–4) GHz. Variable band rejection between (2.95–4.40) GHz can be achieved by adjusting the “Wa” values. When measured over the band rejection frequency, the return loss (S11) and VSWR values are very close to 0 dB and larger than 2. The simulated and measured results such as return loss, VSWR, 2-D polar pattern and gain have almost similar agreement. The design of the suggested antenna is simple, compact and efficient for Wi-MAX application, this is an ideal UWB antenna with the band notch characteristics.

Improvement in the Gain of UWB Antenna for GPR Applications by Using Frequency-Selective Surface

In this article, high-gain ultra-wideband (UWB) monopole antenna is presented. The UWB monopole antenna is a semicircular-shaped antenna with a semicircular slot at the top side. The bottom plane consists of partial ground with triangular and rectangular slotted structures to improve the impedance bandwidth of the proposed antenna. In order to enhance gain, a 6 × 6 metallic reflector (FSS) is placed below the antenna. The performance of the offered design is validated experimentally. The simulated results show resemblance with the measured results. The antenna resonates for the UWB ranging from 3 to 11 GHz. Moreover, the integration of FSS improves the average gain by 4 dB, where peak gain obtained is 8.3 dB across the UWB. In addition, the reported unit cell having dimension of 0.11 λ × 0.11 λ gives wide bandwidth (7.2 GHz) from 3.3 GHz to 10.5 GHz. The performance of the proposed antenna determines its suitability for the modern day wireless UWB and GPR applications.

Wireless Powering and Telemetry of Deep-Body Ingestible Bioelectronic Capsule

In this article, a complete and efficient wireless power transfer (WPT) system, consisting of a full-duplex antenna, a half-wave rectifier, and a WPT transmitter (Tx), is designed and validated for deep-body ingestible biomedical capsules. A two-port full-duplex antenna is adopted to perform seamless telemetry and to act as a receiver for WPT Tx without using a multiplexer circuit. The full-duplex implantable antenna operates at 915 MHz (Port 1) and 1300 MHz (Port 2) and occupies compact dimensions of 8 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times $ </tex-math></inline-formula> 8 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times $ </tex-math></inline-formula> 0.13 mm 3. It maintains high isolation of >30 dB and peak realized gains of −19.3 dBi at 915 MHz and −17.7 dBi at 1300 MHz. The miniaturization of this antenna is achieved using semicircular slots on the patch and circular slots on the ground plane while mutual coupling between the ports is reduced by a series of metallic vias. Moreover, a low-profile and efficient rectifier is designed at 1300 MHz and integrated with port 2 of the antenna. The suggested rectifier achieves a radio frequency (RF) to direct current (dc) conversion efficiency of 80.4% at an input power of 1 dBm. Furthermore, a patterned patch antenna is designed that acts as a WPT Tx for the biomedical capsule. After examining the individual performance of the antenna, rectifier, and WPT Tx, the overall WPT system is then validated by placing the capsule (rectifier integrated antenna) inside minced pork meat and powered by the WPT Tx. This WPT system is suitable for modern capsule devices due to its features, such as compact size, high gains, high RF-dc conversion efficiency, simultaneous wireless powering and telemetry, and high-power transfer efficiency (PTE).

Dual Band Microstrip Semicircular Slot Patch Antenna for WLAN and WIMAX Applications

Dual Band Microstrip Semicircular Slot Patch Antenna for WLAN and WIMAX Applications

Design of Dual Mode AVA with Enhanced Radiation Characteristics

This paper presents the design of a Dual mode antipodal Vivaldi antenna (AVA) with narrowband to wideband switching characteristics. The radiation characteristics are improved by loading the semi-circular slots on the radiator based upon the surface current analysis. This resulted in gain enhancement and the lower resonance frequency improvement. High-frequency switching is achieved via PIN diodes with proper biasing circuits. The proposed antenna is fabricated on a low-profile FR-4 substrate with the dimensions of 60 mm x 40 mm x 1.6 mm. The proposed antenna exhibits 8.3 GHz bandwidth in wideband mode with a peak gain of 6.9 dBi and 1.6 GHz bandwidth in narrowband mode with a peak gain of 7 dBi. Reference antenna is fabricated with the same dimension and utilized for the comparison with the proposed antenna. All the simulation results are carried out using CST full-wave simulator. The working principle of the antenna is explained through simulation and verified through measurements.

A Compact Semi-circular Slot MIMO Antenna with Enhanced Isolation for Sub-6 GHz 5G WLAN Applications

A Compact Semi-circular Slot MIMO Antenna with Enhanced Isolation for Sub-6 GHz 5G WLAN Applications

Gain improvement of THz antenna using semicircular slot and modified ground plane

SummaryIn this paper, gain improvement and impedance matching of THz patch antenna by using semicircular slot and modified ground plane are discussed. The proposed antenna consists of a simple rectangular patch configuration. The novelty of the proposed antenna is its semicircular slot, and modified ground structures are used to enhance the gain and impedance matching of the proposed antenna. Design evolution along with parametric studies is also offered in this paper along with the return loss comparisons. Surface current distributions that are presented for the validation of proposed antenna's operation are controlled by the slots. The effect of slots on performance of the proposed antenna is also offered in this paper. The proposed antenna is designed and simulated on CST software. The proposed antenna occupies a compact area of 100 × 150 × 10 μm3, which in terms of wavelength can be given by 0.33 0.5 0.03 where is the free space wavelength at 1 THz. The proposed antenna has a resonant frequency of 1 THz with a realized peak gain of 8.87 dBi and efficiency of 87%, respectively. The proposed antenna can be a suitable candidate for 1‐THz applications.

Research on cogging torque of the permanent magnet canned motor in domestic heating system

The permanent magnet canned motor (PMCM) is a new type of energy-saving motor used in domestic heating system. Starting from the operating environment of the equipment, this paper studies the operating state of the motor. Based on the analysis of the motor structure and the maximum operating conditions, the method of weakening the cogging torque of the motor is studied, and the auxiliary slot method is selected to weaken the cogging torque of the PMCM. The finite element model of the motor is established, the influence of the number and type of auxiliary slots on the cogging torque is analyzed. Through analysis and calculation, it is concluded that the cogging torque of the motor can be reduced when the number of auxiliary slots is two. At the same time, compared with various slot types, the semicircular slot type has the smallest cogging torque. The circle helps to improve the flow of magnetic field and will not form corners and cause magnetic field deposition. This paper has certain engineering application value for the optimal design of the PMCM.

Performance Analysis of Microstrip Antenna with Several Feed Networks for Satellite Communication

The modern wireless communication systems demand significantly higher bandwidth with a highly directive antenna for better performance. For this purpose, the feed networks such as Series Feed (SF), Corporate Feed (CF), and Corporate-Series Feed Network (CSFN) in the design of antennas play a vital role. Therefore, in this paper, rectangular microstrip antennas with inner ring slot, two semi-circular slots on both sides of the microstrip, and two director elements have been designed. The proposed antennas in four sets with different shapes for satellite communication operate at the Ku-band frequency. In this design, copper (annealed) has been used as material for the ground plane. The substrate material of this proposed antenna is Rogers RT5880, with a dielectric constant at 2.2. Moreover, the probe feed technique has been used in this antenna, further followed by SF, CF, and CSFN networks. The presented design is simple, compact, and very economical with optimal gain and bandwidth. The structure parameters of this proposed antenna are numerically computed. The antenna features are simulated by CST Microwave Studio, a commercial simulator based on finite integration techniques that support the numerical analysis. Further, the antenna performances based on the considered feeding techniques of the proposed antenna have been compared.

Microstrip Patch Antenna Designs with Quarter-Circular and Semi-Circular Slots in Patches for Wireless Communication Applications in Frequency Range of 1.2 GHz-4.6 GHz

Microstrip Patch Antenna Designs with Quarter-Circular and Semi-Circular Slots in Patches for Wireless Communication Applications in Frequency Range of 1.2 GHz-4.6 GHz

MIMO Antenna System with Self Isolation Characteristics for GSM and sub-6 GHz 5G Applications

A compact dual-element multiple input multiple output (MIMO) antenna with self isolation characteristics exhibiting dual band characteristics covering GSM-900 (0.88–1.08 GHz) and sub 6 GHz band for 5G (3.11–4.63 GHz) has been proposed. In the proposed design, two semicircular slots have been cut from the radiating part to attain the wide spectrum for 5G. Further, a rectangular open ended slot have been cut from the middle of the partial ground plane to obtain the two bands without rising the overall dimensions of antenna. The whole dimensions of the suggested MIMO antenna is $$48 \times 27{ } \times 1.6\,{\text{mm}}^{3}$$ . It gives a high isolation (19 dB) and broad bandwidth (1.52 GHz) for 5G applications simultaneously without employing external decoupling structures. Further, MIMO performance has been analyzed by particular diversity parameters such as envelope correlation coefficient, diversity gain and mean effective gain. For the validation of results, the suggested antenna is fabricated and experimentally tested.