Analysis Method of Bending Effect on Transmission Characteristics of Ultra-Low-Profile Rectangular Microstrip Antenna

With the advent of wearable communication devices, microstrip antennas have developed multiple applications due to their ultra-low-profile properties. Therefore, it is essential to analyze the problem of frequency shift and impedance mismatch when the antenna is bent. For the case of a rectangular patch antenna E-plane bent on the cylindrical surface, (1) this paper introduces the effective dielectric constant into the cavity model, which can accurately predict the resonance frequency of the antenna, and (2) according to the equivalent circuit model of the antenna resonance mode, the lumped element parameters are calculated based on the above effective dielectric constant, so that impedance characteristics and the S-parameter matching the port can be quickly constructed. From the perspective of circuit frequency characteristics, it explains the change in the transmission performance of the curved antenna. The experimental results show that the maximum difference between the experimental and theoretical calculation frequencies is less than 1%. These results verify the validity and applicability of the theory in the analysis of ultra-low-profile patch antennas and wearable electronic communication devices. It provides a theoretical basis for the fast impedance matching of patch antennas under different working conditions.

Broadband high gain cavity resonator antenna using planar electromagnetic bandgap (EBG) superstrate

This paper presents a broadband miniaturized Fabry–Perot cavity resonator antenna (CRA) made of novel electromagnetic bandgap (EBG) superstrate as partially reflecting surface (PRS) and reactive impedance surface (RIS) backed rectangular patch antenna. To the best of the authors' knowledge, the proposed EBG exhibits the highest stopband bandwidth (BW) with a bandgap existing between 7.37 and 12.4 GHz (50.9%). Frequency-selective property of the EBG is utilized under plane wave incidence to demonstrate it as PRS superstrate in CRA antenna. The cavity is excited with a rectangular microstrip antenna which is made of two dielectric substrates with an additional RIS layer sandwiched between them. The RIS provides wideband impedance matching of the primary feed antenna. A 7 × 7 array of the EBG superstrate is loaded over the patch antenna having an overall lateral dimension of only 45 × 45 mm2 or 1.62 λ0 × 1.62 λ0 where λ0 is the free space wavelength at the center frequency of 10.8 GHz. The proposed Fabry–Perot CRA (FP-CRA) achieves gain enhancement of 6.59 dB as compared with the reference antenna and has a 10 dB return loss BW of 23.79% from 10.07 to 12.79 GHz. A prototype of the FP-CRA is fabricated and experimentally tested with single and dual layers of EBG superstrate. Measured results show BWs of 21.5 and 24.8% for the two cases with peak realized gain of 12.05 and 14.3 dBi, respectively. Later a four-element antenna array with corporate feeding is designed as the primary feed of the CRA. The simulation result shows a flat gain of >13 dBi with gain variation <1.2 dB over the impedance BW of 13.2%.

Realization of multiple-band terahertz metamaterial absorber using two identical split rings having opposite opening directions connected by a rectangular patch

Multiple-band metamaterial absorber at terahertz regime using periodically arranged surface structure placed on ultra-thin thickness of insulating dielectric slab backed by a metallic ground plane is demonstrated in this paper....

Optimized Bandwidth Enhanced Wideband Microstrip Antenna for 5G Applications

In this article, a single port with truncated corner and common T-shaped notch loaded microstrip patch antenna for bandwidth enhancement is presented which is useable for mid band of 5G applications. The design of this prototyped antenna is obtained by loading truncated corner and T-shaped notch on rectangular patch antenna having 50 Ω microstrip line feed. The optimized antenna 5 is selected as proposed antenna at design frequency 3 GHz among antenna 1- antenna 5after study of simulated results through IE3D Mentor Graphics simulation software. Proposed antenna covers a wide bandwidth from 2.39 to 4.04 GHz and fractional bandwidth of 51.3% with pair of resonance frequency having return loss of -23.38 dB and -29.65 dB respectively.

Gain and Bandwidth Enhanced Optimized Notch Loaded Microstrip Antenna for 5G Applications

In this paper, a rectangular patch antenna is presented loaded with T-shaped notch as well as having truncated corner for the enhancement of gain and bandwidth which is bring into play for mid band of 5G applications. With design frequency of 3 GHz, this prototyped design antenna having 50 Ω microstrip line feed for impedance matching and simulation has been performed using IE3D Mentor Graphics simulation software. Fractional impedance 51.3% has been observed from 2.39 to 4.04 GHz. An enhanced peak gain of 5.05 dBi and maximum directivity of 6.214 dBi has been observed at 4.22 GHz and 4.34 GHz respectively.

Effects of the Feedline Position on Microstrip Patch Antenna Performance

In this study, it is aimed to demonstrate the effects of the feed line position on the operating frequency, return loss and bandwidth of the rectangular patch microstrip antenna. For this purpose, a compact-sized antenna that can operate at 2.4-2.45 GHz frequencies is designed in High Frequency Structure Simulator (HFSS) program. Then, the position of the feedline is changed horizontally and vertically, and its effects are observed. The results obtained after the modificaions are given and discussed. It is stated that the feed line position is a very important parameter that affects the basic characteristics of the antenna.

A Flexible Broadband CPW-Fed Circularly Polarized Biomedical Implantable Antenna With Enhanced Axial Ratio Bandwidth

Implantable antennas have a vital role in biomedical telemetry applications. Therefore, a compact low-profile circularly polarized biomedical implantable antenna operational in industrial, scientific, and medical (ISM) band at 2.45 GHz is reported. The presented antenna is fed by a modified co-planar waveguide (CPW) technique to keep the size of the antenna compact. The radiating monopole consists of a slotted rectangular patch with one slot at an angle of 45 degree and truncated small patch on the left end of the CPW ground plane to make the antenna circularly polarized at the required frequency band. A flexible Roger Duroid RT5880 substrate (εr = 2.2, tanδ = 0.0009) with the standard thickness of 0.254 mm is used to achieve bending abilities. The complete volume of the designed antenna is 21 mm × 13.5 mm × 0.254 mm (0.25 × 0.16 × 0.003 ). The antenna covers the bandwidth from 2.35-2.55 GHz (200 MHz) in free space while from 1.63 GHz to 2.8 GHz (1.17 GHz) inside skin tissue. As the designed antenna is operational in skin tissue with larger bandwidth, the bending analysis along the (x & y)-axis is also analyzed through the simulation. A good agreement between the simulation and measurements of the bended antenna is observed. The measured -10dB impedance bandwidth and the 3dB axial ratio (AR) bandwidth inside skin-mimicking gel are 47.7% and 53.8%, respectively at 2.45 GHz frequency band. Finally, the specific absorption rate (SAR) values are also analyzed through simulations, and it is 0.78 W/kg inside skin over 1 g of mass tissue. The proposed SAR values are less than the limit of the federal communication commission (FCC). This antenna is miniaturized and an ideal applicant for the biomedical implantable applications.

DESAIN ANTENA MIKROSTRIP E-SHAPED PATCH PADA FREKUENSI 5500 MHz UNTUK WIFI

Modifying the shape of the patch microstrip antenna is one way to solve the narrow bandwidth. E-Shaped patch microstrip antenna is obtained by modifying a rectangular patch mikrostrip antenna. The results on this research have succesfully compared the design and simulation antenna parameters between rectangular patch and E-shaped patch. It uses FR-4 as a substrate and works on 5500 MHz frequency for WiFi. The feeding method using a feedline method. The E-shaped patch microstrip antenna has a VSWR value of 1.04 and the antenna return loss is -33.73 dB, better than the rectangular patch. The gain of E-shaped patch is increased by almost 2.5 times and the bandwidth is increased by 10.18% compared to the rectangular patch. The radiation pattern of the two patches has the same directional radiation pattern.

An Eigenmode Study of Nanoantennas from Terahertz to Optical Frequencies

In this work, we present a rigorous full-wave eigenanalysis for the study of nanoantennas operating at both terahertz (THz) (0.1–10 THz), and infrared/optical (10–750 THz) frequency spectrums. The key idea behind this effort is to reveal the physical characteristics of nanoantennas such that we can transfer and apply the state-of-the-art antenna design methodologies from microwaves to terahertz and optics. Extensive attention is given to penetration depth in metals to reveal whether the surface currents are sufficient for the correct characterization of nanoantennas, or the involvement of volume currents is needed. As we show with our analysis, the penetration depth constantly reduces until the region of 200 THz; beyond this point, it shoots up, requiring volume currents for the exact characterization of the corresponding radiating structures. The cases of a terahertz rectangular patch antenna and a plasmonic nanoantenna are modeled, showing in each case the need of surface and volume currents, respectively, for the antenna’s efficient characterization.

CPW-Fed Penta Band Monopole Antenna for Multiservice Wireless Applications

A compact triple T-shaped stub with meander loaded strip antenna for penta band applications is proposed. The rectangular patch antenna with meandered and open-ended slot cuts is utilized to realize four operating bands at 2.45 GHz, 3.1 GHz, 5.3 GHz, and 6.5 GHz with an impedance bandwidth of 400 MHz (2.15-2.550 GHz), 1000 MHz (2.7-3.7 GHz), 200 MHz (5.4-5.6 GHz), and 200 MHz (6.4-6.6 GHz), respectively. For an additional resonance frequency, the length of the central T-shaped stub is slightly modified which causes the variation in the current distribution. As a result, the resonance frequency of 5.5 GHz is divided into two resonance frequency bands which are operating at 5.25 GHz and 5.85 GHz with an impedance bandwidth of 100 MHz (5.25-5.35 GHz) and 200 MHz (5.75-5.95 GHz), respectively. Furthermore, a parametric reflection coefficient and surface current distribution analysis is carried out to understand the strip and slot behavior at resonance frequency bands. Finally, a prototype is fabricated and its reflection coefficient, gain, and radiation pattern are measured. The experimental result shows that the proposed antenna is reliable for penta band applications.