ESPAR Array Design for the Wireless Communication and IoT Applications

doi:10.21203/rs.3.rs-1448202/v1

Download PDF

Research Article

ESPAR Array Design for the Wireless Communication and IoT Applications

https://doi.org/10.21203/rs.3.rs-1448202/v1

This work is licensed under a CC BY 4.0 License

Journal Publication

published 30 Nov, 2023

Read the published version in Telecommunication Systems →

You are reading this latest preprint version

It is very important to handle the interference between the transmitter and receiver in wireless communication system. The high gain antenna is an essential component in such a communication system. In this paper, a new Electronically Steerable Parasitic Array Radiator (ESPAR) array antenna is presented for high gain communications and sensing. The antenna array (1x2) consists of two single ESPAR antennas with an optimum distance. The maximum gain of the single antenna is 8.17 dB whereas the minimum gain is 7.88 dB. Likewise, the peak gain of the array antenna is 11.40 dB which increased by 3 dB approximately. The designed antenna could operate at the frequency of ISM band 2.4 GHz to 2.50 GHz. The elements of the ESPAR antenna are placed on substrate namely Rogers RO4725-JXR with a thickness of 0.787 mm whose dielectric constant is 2.55, as a result it could be fabricated inexpensively. The space between the active and parasitic elements is chosen as λ/4 for optimum performance. To reduce the mutual coupling, the distance between the two ESPAR antennas is selected as λ/8. This proposed array design of ESPAR antenna could be applied into wireless communications, in wireless sensor networks (WSNs) and IoT communication applications.

ESPAR Array antenna

High Gain

WSN Communications

IoT Applications

In any wireless communication system, antenna is a vital component. Antennas are used to connect two or more devices over long distance wirelessly through the air medium [1, 7]. If the antenna gains are higher, it could easily handle the interference by providing strengthen information signals at the receiver [8]. For this the array antenna is the best choice to enhance the gains. The first array antenna was introduced in the 1940s. This development was significantly used in wireless communications because it improves the reception and transmission systems with minimum interference [2, 3]. The antenna array consists of N-radiated elements applied to special functions. Feeding can be done specifically to achieve the goals of increasing gains or maintaining radiation patterns or maintaining alignment [4, 22]. In this way, the array antenna is widely used in the recent communication systems due to its advantages as like higher gains, and better radiation patterns and power efficiency. Additionally, it is very important to use the array antennas for the faster data rate in any dense communication systems efficiently and for the sensing many targets or sensors [6, 25, 29]. However, it is a big challenge to design this array antenna using optimum radiator. The main goal of this research is to propose the high gain Electronically Steerable Parasitic Array Radiator (ESPAR) antenna with its 1x2 array to face the interference because adopting the antenna array is an effective way to improve the system performance. ESPAR is the technique by which beam steering is achieved without the use of phase shifters at any particular directions. In ESPAR antenna, a driven element is surrounded by the closely spaced parasitic elements [16].

The ESPAR array antennas are arranged in such a way that the distance between each antenna is λ/8, also the space/ gap between the active and passive elements is λ/4 by which it could easily reduce the co-channel interference [18–19]. The proposed single ESPAR antenna’s maximum gain (8.17 dB) is much higher than the previously published antennas like 6.99 dB [9], 5.70 dB [16], and 7.73 dB [17]. As compared to the other array antennas gain 7.51 [3], 8.50 [4], 9.91 [27], the gain (11.40 dB) of the suggested array antenna is also higher (9.95 dB to 11.4 dB). Based on the other parameters i.e., reflection coefficient, radiation pattern, and directivity, the designed array antenna’s performance is also exhibited as much better.

In this paper, we like to propose a new ESPAR (Electronically Steerable Parasitic Array Radiator) array antenna/ ESPAR antenna to make a beamforming at a particular direction. The beam steering of the proposed ESPAR antenna exhibits very high performance regarding the gains of 8.17 dB, reflection coefficient of -24.90 dB, and the wider operating bandwidth of 270 MHz. The beamforming of the antenna can be performed efficiently in the directions of ${0}^{0}$,${45}^{0}$,${90}^{0}, {135}^{0}$,${180}^{0}$,${225}^{0}$ ${270}^{0}$, ${315}^{0}$ respectively.

The main features of the proposed ESPAR/ array of ESPAR antenna can be summarized as follows:

The suggested single, and array of ESPAR antenna are capable to work at (2.40 ~ 2.49) GHz frequency;
The gain of the single ESPAR, and array of ESPAR antenna are relatively higher than many published single and array antennas;
The bandwidths of the proposed antenna are also larger than the many published once antenna papers at the respective frequency band;
Overall, the proposed antenna is considered reliable and robust to be used in the ISM band frequency system applications.

The rest of the paper is arranged as follows. The following section II describes the related works resume. Section III describes the array factor overview, the model of the proposed ESPAR antenna and its evaluation based on the simulation result is presented in section IV. Finally, the conclusion of this manuscript is drawn in section V.

Ultra-wideband patch antenna arrays of 2x1 and 2x2 are presented in [1] whose gain increases from 1 to 2.50 dB as compared to the single one, and the resonating frequencies of these array antennas are 3.40 GHz, 5.80 GHz, 8.60 GHz, and 12 GHz. The maximum gain of this published paper is approximately 6 dB. A novel microstrip patch antenna array with two elements presented to be operated at 5.90 GHz frequency in [2] that uses Rogers RT 5880 material as substrate. The peak gain of this array antenna is 9.61 dB whereas the single antenna gain is 7.51 dB. In [3], the patch array antenna with 1x2 elements is proposed with two input ports by providing the center frequency of 2.30 GHz and 3.50 GHz, the respective gains are obtained as 10.10 dB and 12.20 dB at these resonating frequencies. As substrate this array antenna used FR-4 material. A two-element array antenna based on a stub-loaded configuration is presented in [4]. Its operating frequency obtained as 2.15 GHz to 2.38 GHz with the maximum gain of 8.50 dB. Dissimilar circular patch antenna of 1x2 and 1x4 arrays are demonstrated in [7] that used FR-4 glass-epoxy dielectric material to cover the band of (2.40–2.48) GHz frequency. The highest gain of this published paper is 8.03 dB. A published paper [8], hexagonal shape 2x2 array of patch antenna with defected ground structure (DGS) is designed to be operated at the frequencies of 2.40 GHz and 5.80 GHz. A 7- elements ESPAR antenna at 2.48 GHz operating frequency for Direction-of-Arrival (DoA) estimation is presented in [5]. The design paper [6] of broadband 7- elements ESPAR antenna is proposed to work for all frequencies in the band of 465 MHz to 700 MHz with the peak gain of 9 dB. A single UHF RFID 13- elements ESPAR antenna [9] is designed on the FR-4 material for operating at the frequency of 2.40 GHz. The peak gain of this ESPAR antenna is 6.99 dB. Paper [10] illustrated a 13- element ESPAR antenna using FR-4 laminate for 2-D direction-of-arrival (DoA) estimation at 2.48 GHz frequency by providing the value of gain is 6.75 dB, also its minimum return loss is exhibited as -14 dB. A 5-elements ESPAR antenna [11] with a sole active element and four parasitic elements is designed for operation at 2.10 GHz frequency, and the minimum return loss at this frequency is approximately – 18 dB. The distance between the active and each parasitic element is set to be λ/14 mm. The research work is performed by the paper of [12] with 7- elements ESPAR antenna, where the distance between active and passive elements is λ/4 at 2.50 GHz frequency. Five-elements ESPAR antenna using slot active element is presented in [13] which fabricated on the FR-4 substrate material to be resonated at 2.45 GHz frequency. The suggested article [16], represents 5- elements ESPAR antenna that can be used for the (2.10– 2.60) GHz frequency band. The crossed monopole of this ESPAR antenna presented for the broadband characteristics of 520 MHz band at a return loss of -15 dB and the antenna gain range about (4.70–5.70) dB. Paper [17] proposed a 7- elements ESPAR antenna to be used for the operating frequency of (1.70–2.70) GHz, the lengths/ heights of the active monopole and the parasite sleeve wires is about λ/4. The gain range of this antenna is from 6.15 dB to 7.37 dB. Lately, paper [19] presented the microstrip patch hole hexagonal design ESPAR antenna whose maximum gain is 7 dB, the minimum reflection coefficient is -19 dB, and the operating frequency bandwidth is 130 MHz.

Array factor (AF) in any system usually depends on the number of antennas, distance between the each antenna, amplitude and phase of the input signals at each element (antenna). The antenna array can be arranged either at z- axis or at x- axis and y- axis in any designed system frequently depicted in Fig. 1(a). To be noted the simplest array antenna consists of two elements separated at a distance of d. The AF for N- elements can mathematically be expressed as [14]

Array Factor, AF($\theta )$ = $\sum _{n=1}^{N}{e}^{f\left(n-1\right)(kd\text{cos}\theta + \delta )}$ (1)

where, Ψ = $Kd\text{cos}\theta + \delta )$then Eq. (1) can be written as

AF($\theta )$ = $\sum _{n=1}^{N}{e}^{f\left(n-1\right)\varPsi }$ (2)

here, k = $\frac{2\pi }{\lambda }$, $\theta$ is the angle between array axis and the observation of azimuthal angle, $\delta$ is the phase shifter which equals to the zero for the broadside array, d is the different antenna’s spacing from each other.

Now, for the simple two elements array, the equation of the array factor (AF) can be written as follows [15]

AF($\theta )$ = $\frac{1}{2}\left|1+ {e}^{j\varPsi }\right|=\left|\text{cos}\frac{\varPsi }{2}\right|$ (3)

For this array, the space between the antennas must be d ≤ λ/2. Otherwise, many side lobes will appear due to the negative value of cosine term for, d > λ/2.

Therefore, when the outputs (gains) from each antenna are combined (${r}_{1}, {r}_{2}, {r}_{3}, \dots , {r}_{n}$is the output of array amplitude sequence), there is a coherent summation that increases the output gain of amplitude as shown in Fig. 1(c). Simply, this scenario can mathematically be defined as follows,

z = $\sum _{n=1}^{N}{r}_{n}$ (4)

A. Single ESPAR antenna

An electronically steerable parasitic array radiator (ESPAR) antenna consists of one active element (fed element or radiator) and the others are the parasitic elements (or parasitic radiators) attached with variable reactance. The proposed ESPAR antenna is designed using the CST studio simulator. The active monopole (numbered as #0) placed in the center of the metal ground plane surrounded by 4- parasitic elements (numbered as #1- #4) printed on Rogers RO4725-JXR dielectric substrate. Its relative permittivity, ${\epsilon }_{r}$= 2.55 and thickness, h = 0.787 mm. To design a low-profile ESPAR antenna, it has to significantly be reduced the height. The original concepts while its radiation patterns can successfully be used to provide accurate direction of arrival estimation, a number of constructions based on the number of radiators have been investigated. The distance between an active element and the passive elements is λ/4 (= a). The active monopole here is fed by the coaxial connector via the central pin in order to provide 50Ω impedance appropriately and its height, ha = 26 mm. The parasitic elements can be opened (directors that pass through the electromagnetic wave) or shortened (reflectors that reflects the energy) to the ground by the pin diode switching circuits designed on dielectric substrate whose height, hp = 27.2 mm. The central pin of every surrounding passive element can be connected to the ground via a corresponding switching circuit realized using inductance and reactance sets. The switching mechanism influences the passive elements resonance by involving additional, centrally located load (close to open or short circuit). As a consequence, the proposed 5- elements antenna provides ${360}^{0}$ beam steering with each ${45}^{0}$ discrete step using n = 8 directional radiation patterns. In such setup, nth radiation pattern will have its main beam direction equal to ${\phi }_{max}^{n}$for which the radiation pattern will have its maximum in the horizontal plane. All considered steering vectors together with associated main beam directions and radiation pattern numbers, n are gathered in table II.

The 3-D radiation pattern of the proposed antenna at all the switching state is illustrated in Fig. 3. By which the antenna will definitely provide the strength connectivity in any networks even though there is a difference in height of installed nodes. Also, the antenna provides standard gain values which are sufficient to be used in weather tracking, WSN system; IoT- based smart city deployments, and so on. Moreover, the impedance matching of the proposed antenna is very good as depicted in Fig. 4, for the first switching state. The reflection coefficient below − 10 dB in the considered frequency band of the antenna is presented. The minimum return loss exhibits as -24.90 dB with a bandwidth of 270 MHz, from where; it could observe that the antenna exactly resonates at 2.49 GHz frequency.

Comparative analysis results with some other published ESPAR antenna papers are demonstrated in Table III, based on the radius, r (mm) of the substrate, maximum height of the antenna elements, h (mm), resonating frequency (GHz), maximum gain (dB), and the value of return loss |S1,1| (dB) of the antenna.

However, the proposed ESPAR antenna has maximum gain of 8.17 dB, minimum value of return loss is -24.90 dB, and the optimum operating bandwidth is 270 MHz with the least side lobe. As compared to the many ESPAR antennas, its size, heights are smaller; also the characteristics parameters exhibit very well in result that is why this might be selected to be used in the respective communication system.

The proposed antenna’s gain during the angular directions of ${0}^{0}$ is 8.17 dB whereas the gain at the time of main lobe angular directions of ${90}^{0}$, ${180}^{0}$, and $27{0}^{0}$ is 8.12 dB, also the gain 7.88 dB obtained at ${45}^{0}$, ${135}^{0}$, $2{25}^{0}$, and $31{5}^{0}$. It happens due to the reactance set of the antenna at different passive elements.

B. 1x2 array of ESPAR antenna

In 1x2 array of 5- elements ESPAR antenna, each ESPAR antenna is arranged in such a way that the distance between the two antennas is about one-eight wavelength, λ/8 to be operated in the ISM band frequency of (2.40–2.50) GHz. The simulation and geometrical design specification of the 1x2 array antenna is illustrated in Fig. 5 with two single 5- elements ESPAR antennas. The lumped ports of the two ESPAR antennas are setup in different way as depicted in Fig. 5(a).

During the first steering vextor in accordance with table IV, the return loss plot of the array antenna is demonstrated in Fig. 6, more specifically the reflection coefficients for S1,1, S2,2, of the 1x2 array 5- elements ESPAR antenna is shown in Fig. 6(a). The S1,1 and S2,2 curves minimum return loss exhibited as – 18 dB. Moreover, the S2,1 and S2,2 curves return loss present below the – 16 dB as illuminated in Fig. 6(b). After combining the farfield results, the final reflection coefficient is displayed in Fig. 6(d), which indicates that the array antenna resonates at 2.46 GHz frequency with minimum return loss of – 21.50 dB. At the time of second steering of the reactance set presented in table IV, the reflection coefficient is shown in Fig. 7. The S2,1 and S2,2 return loss curves present below the – 25 dB as illustarted in Fig. 7(b), and the Fig. 7(c) is presented as the combined result. Again, when the ${\phi }_{max}^{3}$ = ${90}^{0}$ folowed by the reactamce set of table IV, the reflection coefficient is depicted in Fig. 8. For the other beam directions, the return loss plot of the proposed array antenna maintain the same result followed by the reactance set table.

The complete 3-D radiation pattern of the proposed 1x2 array antenna is displayed in Fig. 9 by following the directions of ${0}^{0}$, ${45}^{0}$, ${90}^{0}$, ${135}^{0}$, ${180}^{0}$, ${225}^{0}$, ${270}^{0}$, and ${315}^{0}$. It’s observed that the peak gain of the proposed antenna is 11.40 dB and the least gain of the array antenna is 9.95 dB.

It is obtained from the presented table V, that the designed array antenna is compared with some published once papers based on the type array of antenna, array dimensions (nxm), operating frequency (GHz), and gain (dB).

This paper incorporates with the design of 1x2 array of antenna by proposing 5- elements ESPAR antenna. The ESPAR array antenna has some advantages like wider elevation angle directions, efficient ${360}^{0}$radiation pattern, higher beam gains, and so on. The beam steering of the proposed array antenna exhibits very high performance at (2.40–2.50) GHz frequency regarding radiation pattern, gains of 9.95 dB to 11.40 dB, reflection coefficients, and the wider operating bandwidth. The beamforming of the single and array antenna can be performed efficiently in the directions of ${0}^{0}$,${45}^{0}$,${90}^{0}$,${135}^{0}$, ${180}^{0}$, ${225}^{0}$, ${270}^{0}$ ${315}^{0}$ respectively. Thus, the proposed design antennas are seemed to be a reliable, and robust for low power transmission system to build a better communication.

ACKNOWLEDGMENTS

This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (Ministry of Education) (NRF-2016R1D1A1B01008046) and this work was supported under the framework of international cooperation program managed by the National Research Foundation of Korea (2019K1A3A1A3910299511, FY2019). Also, this work was supported under the framework of international cooperation program managed by the National Research Foundation of Korea (2020K2A9A2A08000106, FY2020).

Dwairi, M. O. (2021). “Increasing Gain Evaluation of 2×1 and 2×2 MIMO Microstrip Antennas,”Engineering, Technology & Applied Science ResearchVol. 11, No. 5,
Technologies, et al. (2018). (ICCCNT), Bengaluru, India,
Ferda Cansu, G., et al. (2020). “A Two-Element Array Design of Dual-Band Quasi- Yagi Antenna with Reflector,” Pro. in IEEE International Symposium on Antennas and Propagation and North American Radio Science Meeting,
Siti Nailah Mastura Zainarry (April 2018). et al, “A Frequency- and Pattern-Reconfigurable Two-Element Array Antenna,'' IEEE Antennas and Wireless Propagation Letters, Vol. 17, no. 4,
Taillefer, E., Hirata, A., & Ohira, T. (2005). ``Direction-of-arrival estimation using radiation power pattern with an ESPAR antenna,'' IEEE Trans. Antennas Propag., vol. 53, no. 2, pp. 678_684, Feb.
Md, M., Rahman, H. G., Ryu, R. F. I. D., & Based, W. S. N. (2021). Communication System in Interference Channel,” Pro. in IEEE International Symposium on Local and Metropolitan Area Networks (LANMAN), USA,
Maciel, A., et al. (2017). “Dissimilar Circular Patch Size Antenna Array with Enhanced Bandwidth and Broadside Gain,” Pro. in SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC), Aguas de Lindoia, Brazil,
Kanchan, W., et al. (2018). “Miniaturization and Gain Enhancement of Array Antenna for Dual Band RADAR System,” Pro. in IEEE Indian Conference on Antennas and Propagation (InCAP),
Mateusz, R., Communications, et al. (2016). (MIKON), Krakow, Poland,
Kulas, L. (2017). “Simple 2-D Direction-of-Arrival Estimation Using an ESPAR Antenna,”IEEE antennas and wireless propagation letters, vol. 16,
Paraskevi, N., Daskalaki, et al. (2014). “Design and Analysis of a 5-element ESPAR Antenna with an Active PIFA,” Procgress in European Conference on Antennas and Propagation (EuCAP),
Jiawen Sun, Y., Ning, & Jiang, W. (2014). “Influence of Parasitic Elements on Characteristics and Design of ESPAR Antenna,” URSI- General Assembly and Scientific Symposium (URSI-GASS), Beijing, China, 20 October
Lee, K. P., “Five-element ESPAR antenna using the annular ring slot active element,”Microwave and Optical Technology Letter, Volume- 58, Issue- 12, December 2016.
Siti Fazlina, M., et al. (2012). “Impact of Number Elements On Array Factor in Linear Arrays Antenna,”Pro. in IEEE International Colloquium on Signal Processing and its Applications,
Apostolov, P. (2021). “Efficient Two-Element Array Antenna,” Pro. in Electronica, Sofia, Bulgaria,
Dong-Cheol, S., et al. (January 2016). “The characteristics of broadband ESPAR antenna with coupled multiconductor strips,”Microwave and Optical Technology Letters, Vol. 58, No. 1,
Liang, Q., Sun, B., Zhou, G., & Li, J. (2018). “Broadband ESPAR antenna using sleeve wires,”Int. J. of RF Microw Computer aided Eng.,Volume28, Issue 9,
Jung-Nam, Lee, et al. (2019). λ/64‐spaced compact ESPAR antenna via analog RF switches for a single RF chain MIMO system. ETRI Journal, 41(4), 536–548
Changyoung An and, & Ryu, H. G. (2021). “Design and Evaluation of ESPAR Antenna using Hexagonal Microstrip Patch with Hole,” Proceeding in ISAP2020, Osaka, Japan,
Bashir, Alshami, et al. “Design of a Broadband ESPAR Antenna,” Mediterrannean Microwave Symposium (MMS), Tangiers, Morocco, 08 February 2010
Shafaq, K., et al. (2013). “ESPAR Antenna System for Dynamic Tracking of Active Targets,” Pro. in European Modeling Symposium, Manchester, UK,
Halim, E. A., Ibrahim, I. M., “Array antenna design for wireless backhaul 3.5 GHz 5G application,” Proceedings in Innovation and, & Competition, T. (2021). (INOTEK), Melaka, Malaysia,
Caspers, E., et al. (2012). “1x8 Quasi-Yagi Antenna Array,”Progress in Applied Computational Electromagnetics,
Toto, S., et al. (2018). “Design of Microstrip Rectangular Circular Array Antenna 1x 8 at Frequency of 1800 MHz for Increase Power of 4G signal,” Journal of Physics: Conference Series, Volume 1364,
Enis, K., et al. (2021). “A Low Profile Highly Isolated Phased Array MIMO Antenna System for 5G Applications at 28 GHz,” Pro. in European Conference on Antennas and Propagation,
Alami, A., et al. (2019). “Design and Simulation of RFID Array Antenna 2x1 for Detection System of Objects or Living Things in Motion,” Pro. in International Workshop on Microwave Engineering, Communications Systems and Technologies (MECST), Belgium,
Salah, I., et al. (2020). “Design and Development of a Microstrip Patch Antenna Array for Rectenna System,” Pro. in International conference on intelligent systems: theories and applications, Morocco,
Md, et al. (2021). “UHF RFID Wireless Communication System for Real Time ECG Monitoring,” Pro. in ICUFN, Korea,
Md, M., Rahman, H. G., & Ryu (2022). “Direction Finding of ESPAR Antenna Based on Beam Scanning Method for IoT Sensor Network,” Pro. in International Conference on Green and Human Information Technology (ICGHIT), Korea,

Table I. Espar Antenna Dimensions

Dimension	Value (mm)	Dimension	Value (mm)
ha	26	hp	27.2
a	λ/4	r	100

Table II. Reactance Set of the Proposed Espar Antenna

Number, n	Directions, ${\varvec{\phi }}_{\varvec{m}\varvec{a}\varvec{x}}^{\varvec{n}}$	Lumped Ports
Number, n		#1	#2	#3	#4
1	0⁰	0.1 pF	0.5 nH	0.5 nH	0.5 nH
2	45⁰	0.1 nH	0.5 pF	0.1 pF	0.7 nH
3	90⁰	0.5 nH	0.1 pF	0.5 nH	0.5 nH
4	135⁰	0.5 nH	0.1 nH	0.5 pF	0.1 pF
5	180⁰	0.5 nH	0.5 nH	0.1 pF	0.5 nH
6	225⁰	0.5 pF	0.1 nH	0.7 nH	0.1 pF
7	270⁰	0.5 nH	0.5 nH	0.5 nH	0.1 pF
8	315⁰	0.5 pF	0.1 pF	0.1 nH	0.7 nH

Table III. Comparative Analysis

Ref.	Radius, r (mm)	Height, h (mm)	Frequency (GHz)	Peak Gain (dB)	\|S1,1\| (dB)
[5]	60.34	30.34	2.48	7	N/A
[9]	246	71	0.87	6.99	-12.2
[12]	60	30	2.50	5.67	-11
[16]	120	30.60	2.40	5.70	-15
[17]	N/A	40.5	2.20	7.73	N/A
[19]	56	N/A	3.50	7	-19
[20]	400	200	0.60	9	N/A
[21]	121.2	N/A	2.45	5.21	N/A
[28]	140	26	2.40	8.44	-16
This	100	27.2	2.49	8.17	-24.9

Table IV. Reactance Set of the Proposed 1x2 Espar array Antenna

Directions,	Lumped Ports
	ESPAR-1				ESPAR-2
	#1	#2	#3	#4	#1	#2	#3	#4
0⁰	0.15 pF	0.45 nH	0.45 nH	0.45 nH	0.2 pF	0.45 nH	0.45 nH	0.45 nH
45⁰	0.45 nH	0.2 pF	0.45 nH	0.45 nH	0.3 pF	0.45 nH	0.45 nH	0.45 nH
90⁰	0.45 nH	0.1 pF	0.1 pF	0.45 nH	0.1 pF	0.2 pF	0.45 nH	0.45 nH
135⁰	0.45 nH	0.45 nH	0.2 pF	0.45 nH	0.45 nH	0.2 pF	0.45 nH	0.45 nH
180⁰	0.45 nH	0.45 nH	0.45 nH	0.15 pF	0.2 nH	0.2 pF	0.45 nH	0.45 nH
225⁰	0.45 nH	0.45 nH	0.45 nH	0.15 pF	0.2 nH	0.45 nH	0.2 pF	0.45 nH
270⁰	0.1 pF	0.45 nH	0.45 nH	0.1 pF	0.45 nH	0.45 nH	0.1 pF	0.1 pF
315⁰	0.2 pF	0.45 nH	0.45 nH	0.45 nH	0.45 nH	0.45 nH	0.45 nH	0.3 pF

Table V. Comparison results and Analysis

Ref.	Array type	Array (nxm)	Frequency (GHz)	Gain (dB)
[22]	Patch	1x8	3.5	6–10
[23]	Patch	1x8	2.4–2.50	6- 9.74
[24]	Patch	1x8	1.80	7.32
[25]	Patch	1x8	28	6.99- 10
[26]	Patch	2x1	2.40	9.22
[27]	Patch	1x2	5.80	9.19
This	ESPAR	1x2	2.40–2.50	9.95–11.4

Download PDF

Journal Publication

published 30 Nov, 2023

Read the published version in Telecommunication Systems →

Reviewers agreed at journal
17 Mar, 2023
Reviews received at journal
16 Apr, 2022
Reviewers invited by journal
16 Apr, 2022
Editor assigned by journal
14 Mar, 2022
First submitted to journal
13 Mar, 2022

You are reading this latest preprint version

ESPAR Array Design for the Wireless Communication and IoT Applications

Status:

Journal Publication

Version 1

Abstract

Figures

I. Introduction

Ii. Related Works And Array Factor

Iii. Espar Antenna And Array Design

Vi. Conclusions

Declarations

ACKNOWLEDGMENTS

References

Tables

Status:

Journal Publication

Version 1