Performance analysis of inserted resonators in microstrip array antenna for biomedical applications

A novel single feed frequency and polarization reconfigurable microstrip patch antenna

This paper presents a dual-polarized single layer metasurface in order to increase the gain of a single microstrip patch antenna in the X-band. The metasurface is comprised of circular unit cells with cross slots, exhibiting the same magnitude (S <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</inf> and S <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">21</inf> ) and phase responses when subjected to TE and TM polarized waves. This single layer planar metasurface can boost the gain of a probe feed single microstrip patch antenna from 7.2 dBi to 16.2 dBi at 10 GHz. The antenna's gain and reflection coefficient with reference to the polarization of the antenna are made stable by employing cross slots, making it a more improved and robust design compared to the metasurface with rectangular slots. Moreover, a strong coupling is observed on the metasurface with cross slots considering both polarized waves.

Radar communication systems are needed to predict weather and other military needs. One of the important parameters required for a radar communication system is an antenna with high performance and broad bandwidth that can improve the resolution. The research proposes a single patch microstrip antenna that is rectangular and has a 8 GHz resonance frequency for radar applications that have high bandwidth and performance. The antenna was developed with two dual feed lines connected to the peradiation element with the 2x1 element array technique aimed at increasing the bandwidth of the frequency. The antenna is designed using a FR-4 substrate with a tangent loss of 0.0265, a dielectric constant ( |r) = 4.3, a substrat thickness (h) = 1.6 mm. The dimensions of the rectangular single patch microstrip antenna substrata are 20x20 mm2 and 35x35 mm2 for the dual feed line antenna design. Simulation results from the antenna development showed a 159.62% increase in bandwidth compared to the original antenna design. The reflection coefficient also increased from the original design antenna, which was -16.36 dB, to -25.64 dB or an increase of 56.72%. This antenna is very suitable and recommended to be applied as a receiver antenna on radar communications systems

Graphene based array antennas are becoming more popular for wireless applications due to their ultra slim structure, versatile nature, flexibility, robustness and other advantages as compared to conventional patch antennas. Small size and high gain coplanar waveguide (CPW) feed single element microstrip patch antenna (MPA), 16 elements array antenna and 32 elements array antenna for millimeter wave applications are presented in this paper. The proposed antenna configurations have been designed and simulated using computer simulation technology (CST). Kapton is used as the dielectric substrate having dielectric constant of 3.5 and thickness of 0.075 mm. Graphene is used in the radiating patch as well as ground plane of the antennas whose electrical conductivity is of 1.4286 × 106 S/m2. The thickness of patch and ground plane are of 0.025 mm and 0.05 mm respectively. Each single element antenna has dimension of 1.75×1.5×0.075 mm3 and each array configuration consist of corresponding number of same dimensional single elements. The results of all the proposed antenna configurations have been analyzed in terms of return loss, bandwidth, gain, VSWR and radiation efficiency. Among all the proposed antennas and analyzed feeding methods, the grounded coplanar waveguide (GCPW) feed 32 elements array antenna shows the best performance.

This paper presents an optimized 868 MHz low-noise amplifier (LNA) based on a bipolar junction transistor (BJT), specifically designed for wake-up receivers operating in the sub-GHz band. The proposed LNA achieves low noise, high gain, and good impedance matching while consuming only 3.2 mA from a 3.3 V supply, resulting in a total power consumption of 10.56 mW. Designing efficient sub-GHz LNAs for low-power applications involves a careful balance between multiple performance metrics. Higher gain typically requires increased biasing current, which can raise power consumption, while achieving a low noise figure often conflicts with input-matching constraints. The presented design addresses these trade-offs by leveraging the BFP740 BJT and employing a stub-based microstrip matching network to simultaneously optimize the gain, noise figure, and input–output matching. Simulation results, using both external lumped elements and microstrip techniques, show a forward gain (S21) of 15.2 dB at 868 MHz, with an input reflection coefficient (S11) of −6.9 dB and an output reflection coefficient (S22) of −6.3 dB. The amplifier achieves a minimum noise figure of approximately 1.77 dB, which is notably low for this frequency band. These results demonstrate that the proposed LNA offers a compact, energy-efficient, and cost-effective solution, ideally suited for always-on, low-power wireless applications such as Internet of Things (IoT) devices and wireless sensor networks.

Objectives: To design new multi-band antennas based on patch resonator with comparative results to each other. Both antennas are compact in size and have high quality responses which can be applied in many handheld and personal communication devices. Methods/Analysis: New microstrip patch antennas based on modified first iteration of Minkowski fractal geometry and applying central small square cut in the main resonator have been presented in this paper with and without inserting corner square patches. Both antennas have designed using single layer and dual feeds to operate as multi frequency devices. The antennas have been modeled and optimized by using the Microwave Office (MWO) simulator based on the method of moments. The projected antennas have been designed using FR4 substrate with a relative dielectric constant of 4.4 and a substrate height of 1.6 mm. Compared with the microstrip patch antenna without inserting corner patches using same main patch resonator dimensions and substrate specifications, the designed antenna with corner patches exhibits more operational frequencies as well as as greater frequency ratios with respect to the first fundamental frequency. Findings: New microstrip antennas based on patch resonator with and without inserting corner patches have been proposed. The first antenna exhibits multi-frequency behavior, where resonances appear to take place at frequencies of 2.49, 3.03and 6.63 GHz, within 2 to 7 GHz frequency range. The second antenna exhibits a higher number of resonant frequencies that appear at 2.14, 2.55, 5.03, 5.81, 5.9 and 6.14 GHz respectively under same previous frequency range. The first three operational frequencies have decreased or shifted by inserting corner square patches due to increased electrical physical dimensions of the second antenna. Also, these corner patches act as EM perturbation elements to stimulate the second antenna with more resonant frequencies within 2-7 GHz frequency sweeping range. Theoretically, there is an important relation between antenna dimensions and guided wavelength. This relation specifies if antenna dimension is less than quarter guided wavelength (λg ), then the antenna is impractical because radiation resistance, bandwidth and gain are decreased and therefore the antenna size is enlarged. By the way, the dimensions of Antennas 1and 2 have been found to be (0.259 λg x 0.259 λg ) and (0.269 λg x 0.269 λg ) respectively according to their fundamental frequencies which are satisfactory. Both antennas have small sizes and high quality responses which can be applied in many handheld and personal communication devices. Novelty/Improvement: In this paper, new multi-band antennas based on patch resonator have been proposed. The proposed resonators have been initiated from the transformed version of the first iteration of Minkowski fractal geometry. These antennas have compact dimensions with good return loss and radiation pattern performances which are desired features to be adopted in many communication devices. Keywords: Compact Antenna, Electronic Design Automation (EDA), Microstrip Patch Antenna, Multi-frequency Antenna, Radiation Patterns.

This paper presents a compact, novel, quad patch and triple band single substrate microstrip patch antenna for 5G/6G mm wave applications. The aim is to design an antenna within the K-band with three resonance frequencies at 24, 29, and 34 GHz. The antenna is designed on a volumetric dimension of 11×12.7×1.6 mm3. The substrate used is FR4 (dielectric constant 4.4), having a loss tangent of 0.0022. A microstrip line of width 1 mm for a 50 Ω impedance line is used to match with the load antenna, which has four rectangular connected patches. Patch dimensions come from standard antenna equations and simulation done on Ansys High-Frequency Structure Simulator software. Validation of simulated results is done through measurements on the prototype antenna. A substantial good agreement is found between the simulated and measured results. The gain of the proposed antenna is 6.16 dBi, with return loss being ≤-10 dB. Bandwidths are 1.1 GHz (23.8 - 24.9 GHz), 0.9 GHz (28.6 - 29.5 GHz), and 0.8 GHz (33.7 – 34.5 GHz), respectively. The far-field radiation characteristics of both E-plane and H-plane are also reported. The proposed design is suitable for mm wave applications, including smart vehicles, global positioning systems, radio frequency identifications, etc.

In this work, we present a self cascode based ultra-wide band (UWB) low noise amplifier (LNA) with improved bandwidth and gain for 3.1–10.6 GHz wireless applications. The self cascode (SC) or split-length compensation technique is employed to improve the bandwidth and gain of the proposed LNA. The improvement in the bandwidth of SC based structure is around 1.22 GHz as compared to simple one. The significant enhancement in the characteristics of the introduced circuit is found without extra passive components. The SC based CS–CG structure in the proposed LNA uses the same DC current for operating first stage transistors. In the designed UWB LNA, a common source (CS) stage is used in the second stage to enhance the overall gain in the high frequency regime. With a standard 90 nm CMOS technology, the presented UWB LNA results in a gain $$\hbox {S}_{21}$$ of $$20.10 \pm 1.65\,\hbox {dB}$$ across the 3.1–10.6 GHz frequency range, and dissipating 11.52 mW power from a 1 V supply voltage. However, input reflection, $$\hbox {S}_{11}$$ , lies below $$-\,10$$ dB from 4.9–9.1 GHz frequency. Moreover, the output reflection ( $$\hbox {S}_{22}$$ ) and reverse isolation ( $$\hbox {S}_{12}$$ ), is below $$-\,10$$ and $$-\,48$$ dB, respectively for the ultra-wide band region. Apart from this, the minimum noise figure ( $$\hbox {NF}_{min}$$ ) value of the proposed UWB LNA exists in the range of 2.1–3 dB for 3.1–10.6 GHz frequency range with a a small variation of $$\pm \,0.45\,\hbox {dB}$$ in its $$\hbox {NF}_{min}$$ characteristics. Linearity of the designed LNA is analysed in terms of third order input intercept point (IIP3) whose value is $$-\,4.22$$ dBm, when a two tone signal is applied at 6 GHz with a spacing of 10 MHz. The other important benefits of the proposed circuit are its group-delay variation and gain variation of $$\pm \,115\,\hbox {ps}$$ and $$\pm \,1.65\,\hbox {dB}$$ , respectively.

Microstrip antenna is expected to be used as part of satellite data reception system since it is more compact, low profile and lightweight than any conventional antenna. This study proposed development circular microstrip antenna with feed line to be implemented in C-band Himawari-8 satellite data reception system. It started with a single circular microstrip antenna then array <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$2\mathrm{x}2$</tex> . The substrate used is FR-4 with 4.3 dielectric constant, both ground and patch used are copper. The width and length of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$2\mathrm{x}2$</tex> array antenna patch is 94.19 mm and 88.49 mm respectively with radius 9.93 mm. Simulation results show that the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$2\mathrm{x}2$</tex> array antenna has better performance than single patch antenna although its bandwidth is slightly lower than single patch. In general, the performance value of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$2\mathrm{x}2$</tex> array antenna in simulation has meet the requirements. The gain of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$2\mathrm{x}2$</tex> array antenna reached 12.37 dB which is way higher than single antenna patch. Furthermore, the process could be continued to design <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$4\mathrm{x}4$</tex> array microstrip antenna to get higher gain than <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$2\mathrm{x}2$</tex> array antenna. After that, the design could be fabricated and integrated to parabolic antenna as a replacement of feed horn antenna which is being used currently for C-band Himawari-8 satellite data reception system.

A novel, compact, single probe-feed square microstrip patch antenna for operation in dual frequency can be achieved by cutting unequal finger like rectangular slots perpendicular to the radiating edges. From the experimental results obtained, the proposed antenna is about 67% smaller compared to a traditional rectangular patch operating at the same frequency and we have got the dual frequency operation in two different bands i.e. L and S bands.

A simple single element rectangular microstrip patch antenna with a semicircular defect on patch surface is proposed to eliminate the electric fields due to first higher order orthogonal mode (TM02) consequently to improve the co-polarized (CP) to cross-polarized (XP) radiation mainly in the broadside direction in H-plane without affecting its co-polarized radiation characteristics. Around 25 dB polarization purity (co-polarized to cross-polarized ratio) is obtained from the proposed structure. The optimum shape of the defect has been chosen with theoretical justification and verified through simulation. Along with the improvement of polarization purity, the proposed structure also reveals moderate gain and miniaturization.

The use of micro-strip antennas in wireless communication is very popular due to their low cost, low profile and ease of fabrication. But poor performances like narrow bandwidth, low gain etc. confines their application. As the upcoming 5th generation (5G) requires high gain antenna, the main concern of this research is to design a high gain micro-strip patch antenna using air substrate. The antenna is designed and simulated using Zeland's IE3D and operates at 28 GHz band. The gain, bandwidth, return loss and efficiency of the single element antenna is 9.82 dBi, 1.29 GHz, 42 dB and almost 100% respectively.

This work is proposed a single layer wideband conformal microstrip patch antenna with low profile suitable for airbone application. Semicircular shape slots located at the corners of the patch and center of the length of the patch along with a partially cut ground plane are utilized to improve the impedance bandwidth of the patch antenna over the standard rectangular patch. The antenna exhibits passband characteristics across multiple bands with fractional impedance bandwidth (VSWR < 2) of about more than 113% with an operating range 4.31–15.691 GHz for the proposed planar and 114% bandwidth with frequency range 4.37–16 GHz for the cylindrical antenna configuration (covering C, X, and Ku bands). Radiation characteristics of both planar and the cylindrical conformed versions of the antenna in both E and H planes are also presented for the corresponding resonant frequencies within the operating frequency range. The effect of the radius of curvature on the resonance curve is also analyzed for the cylindrical conformal patch antenna.

In this paper, we present a novel design of a single feed large frequency ratio dual-frequency microstrip patch antenna with orthogonal linear polarizations. In order to achieve large frequency ratio, two microstrip wings were set on both sides of the main patch, which connects with the help of PIN diodes. The PIN diodes also help improve cross polarization discrimination at the high frequency band. Additional results will be presented during the symposium.

In this paper, a new broadband low noise amplifier (LNA) is proposed. The LNA utilizes a composite NMOS/PMOS cross-coupled transistor pair and a difference amplifier to in-crease the linearity while reducing the noise figure. The introduced approach provides partial cancellation of distortion and noise generated by the input transistors, hence, degrading the overall distortion. The LNA is implemented by using the UMC 130 nm CMOS technology node. The post simulation shows that a conversion gain equals 16.2 dB across 0.05-3.1 GHz frequency range, an IIP3 is +9.2 dBm, and minimum and maximum noise figure are 1.4 dB and 2 dB, respectively. The LNA consumes 32.4mW from 1.8 V supply and occupies an area of 0.075 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> .