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. 2025 Apr 18;15:13480. doi: 10.1038/s41598-025-97276-w

A shared aperture multiport antenna for rural wireless communication and safety monitoring using TVWS, ISM, and 5G mmWave bands

Md Abu Sufian 1, Sang-Min Lee 2,✉, Domin Choi 3, Jaemin Lee 3, Dongkyu Sim 3, Minyoung Song 1, Nam Kim 3,✉
PMCID: PMC12008313  PMID: 40251305

Abstract

To accommodate the antenna demand for rural communication and safety monitoring a shared aperture muti-port antenna sensor is presented for three different operating frequencies covering both Sub- 6 GHz and 5G millimeter-wave bands. The antenna sensor is designed on a single substrate, while different ports are connected to different radiating elements to achieve multiple frequency responses. The simulated and measured findings show that the presented antenna can cover TV-white-space (TVWS) frequency band, 5.8 GHz ISM band, and the 5G millimeter-wave frequency band. At the TVWS band, the antenna yields an omnidirectional radiation pattern with a peak gain of 3.14 dBi. While the antenna provides a unidirectional radiation pattern at the 5.8 GHz ISM and 5G millimeter-wave band with a peak gain of 6.76 dBi and 7.68 dBi, respectively. Moreover, all the antenna ports offer a radiation efficiency of more than 92%. Additionally, the 2-port MIMO configuration at the 5G millimeter-wave band shows excellent MIMO diversity performances by utilizing the proposed novel decoupling structure, which consists of metallic stub and cavity vias. Overall performance of the proposed antenna, especially the three operating frequency band including the TVWS band, makes it a viable solution for the sensing and communication in rural areas.

Keywords: Antenna sensor, TVWS sensing, Sub- 6 ghz and millimeter-wave sensing, Shared-aperture antenna, Multi-port antenna, MIMO communication, Safety monitoring, Disaster response, Sensor for rural areas

Subject terms: Electrical and electronic engineering, Techniques and instrumentation

Introduction

In recent years, with the advancement of wireless communication technologies, antennas offering multiple frequency bands are becoming exceptionally popular among researchers for their ability to perform the tasks of multiple antennas1,2. These antennas are vital for resolving the various challenges of rural sensing applications including monitoring environmental conditions and agricultural activities, seamless wireless connectivity, and efficient disaster management3. However, selecting the antenna operating frequency for rural sensing and communication applications is very critical. As there is an antenna design tradeoff between the operating frequency and the coverage area. The lower frequency band outperforms the higher frequency band in terms of the antenna coverage area. While the higher frequency band such as the 5G millimeter-wave band offers a wide range of antenna bandwidth to accommodate a vast number of users with ultra-fast data transfer capabilities4,5.

Recently, the TV white space (TVWS) frequency bands, which refer to the unused frequency spectrum of television broadcasts (between 470 MHz and 780 MHz), have become very popular among researchers for their benefit of covering longer distances6,7. TVWS can be an excellent solution to communicate in rural and remote areas using TV broadcast towers where the number of base stations is limited. However, very few printed TVWS antennas have been reported in the literature7–9. In8, a system-embedded TVWS antenna is presented. The antenna offers a good omnidirectional radiation pattern; however, the antenna suffers from a low gain and does not cover the whole TVWS frequency band. On the other hand, the antennas in8and9provide a good gain but they occupy a very large antenna area7or cannot offer the full TVWS frequency band9.

Additionally, the 5.8 GHz ISM band and the 5G millimeter-wave frequency band are adopted rapidly in modern wireless communication modules for short-distance body area networks10,11and ultra-fast communication12,13, respectively. Several antennas are reported in the literature for the 5.8 GHz band10,11,14–16and 5G millimeter-wave frequency band12,13,17–20applications. In these works10–20various techniques have been utilized to improve the antenna performances in terms of bandwidth, gain, and radiation efficiencies. However, none of these works offer the TVWS frequency band along with the 5.8 GHz ISM or the 5G millimeter-wave band. To achieve the multi-standard operating frequency band from a single antenna module, the shared aperture antenna techniques can be utilized20–26. A beam-steerable shared aperture antenna is presented in20for 3.5 GHz and 28 GHz dual-band applications. Where multiple substrate and metallic layers along with metallic vias are utilized to achieve beam-steerable and dual operating frequency capabilities. In21electromagnetic structures are adopted to create the shared aperture antenna for four different frequency bands. Similarly, the others reported works22–26used multiple substrate layers with different techniques to create the multiband shared aperture antenna, Fabry-Perot cavity with folded reflect array22, magnetoelectric dipole23, artificial magnetic conductor24, quasi-Yagi structure25, and metasurface structure26. However, none of these reported works offers the TVWS operating band. And all of these works suffer from complex design procedures.

In this proposed work a shared aperture multi-port antenna sensor is presented for three different operating frequencies. The communication scenario of the proposed shared aperture multi-band antenna is presented in Fig. 1. Initially, a TVWS antenna is designed with an omnidirectional radiation pattern to sense any signal from any distant metropolitan area. The TVWS antenna consists of a slotted monopole that utilizes a partial ground plane.

Fig. 1.

Fig. 1

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The communication and sensing scenario of the proposed shared aperture multi-band antenna.

Subsequently, to fully reuse the antenna substrate a circular antenna with four rectangular slots is designed and optimized at the lower left side of the feedline of the TVWS antenna for the 5.8 GHz ISM band. Afterward, on the right side of the substrate, a 2-port 5G millimeter-wave MIMO antenna is created for the wideband 5G communication, while a novel decoupling technique consisting of parasitic element with cavity vias is proposed and utilized efficiently to achieve high isolation between the MIMO elements. To the author’s knowledge, no antenna modules have been reported in the literature that operate at the TVWS band while also covering the 5.8 GHz ISM band and the 5G millimeter-wave band. The proposed design approach enables the antenna system to sense and communicate efficiently at both shorter and longer distances due to its combination of very low and high operating frequencies. The CST 2023 academic software is used for all the antenna simulations27. Then, to validate the proposed work a prototype of the proposed antenna is manufactured and tested. The rest of the paper is organized as follows. The antenna geometry and design procedure are presented in section II. Whereas section III contains the results and discussion. Section IV presents a performance comparison with the other documented shared-aperture antennas in the literature. Finally, section V conveys the conclusion of the proposed work.

Proposed shared-aperture multi-port antenna design

This section explains the method by which the proposed antenna is designed. The shape and other design parameters of the antenna are provided in the first subsection. And in the following subsection the design process is described.

Geometry of the proposed antenna sensor

The layout of the proposed shared-aperture multi-port antenna sensor for TVWS, 5.8 GHz ISM and 5G millimeter-wave frequency band is depicted in Fig. 2. The proposed antenna sensor is created on a 1.52 mm thick Taconic TLY- 5 substrate having a relative permittivity of 2.2 and loss tangent of 0.0009. In the following subsection, the antenna design strategy is explained. And the optimized values of the design parameters for the proposed antenna are listed in Table 1.

Fig. 2.

Fig. 2

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Schematic and design parameters of the proposed shared-aperture multi-port antenna sensor (a) front and back view (b) design parameters of Ant- 2, and (c) design parameters of Ant- 3 and Ant- 4.

Table 1.

Optimized values of design parameters (unit = millimeter).

Variable Value Variable Value Variable Value Variable Value
W 111 G 1 111.8 L 3 5 P 2 8
L 178 G 2 8.9 L 4 13.5 R 9.35
D1 = D2 4.44 f 1 5 S 1 1.75 M 1 76
D 3 17.8 f 2 3.11 S 2 1.7 M 2 12
D 4 59.12 f 3 1.2 S 3 3 M 3 72
D 5 9 f 4 1 S 4 44 N 1 51.65
D6 = D8 5 L 1 110 S 5 1.47 N 2 15.5
D 7 2 L 2 57.3 P 1 7 r 0.3
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Design procedure

A detailed step-by-step design procedure of the proposed shared-aperture multi-port antenna sensor is conveyed in this sub-section along with the results of different design stages. This sub-section also explained the critical design parameters which help the antenna optimization to achieve the targeted performance.

TVWS antenna design for wider sensing coverage area

The design process of the proposed shared-aperture multi-port antenna sensor is started by designing a monopole antenna on a 1.52 mm thick Taconic substrate for the TVWS frequency band, while the edge feeding technique is.

utilized. Major design stages and the corresponding frequency responses of the TVWS band are presented in Fig. 3. The initial width (W) of the radiating element is predicted using the Eq. (1)28, whereas c is the speed of light, fr is the targeted frequency, and Inline graphic is the substrate’s dielectric constant. Afterwards the parameters are optimized for better performance.

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Fig. 3.

Fig. 3

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Different design stages for the initial TVWS band antenna and its frequency responses.

It can be observed from Fig. 3 that, initially the designed antenna, step- 1, offers a very narrow bandwidth. And step- 2 doesn’t offer a good frequency response. While the proposed structure, triangular slot on the radiating patch and square slot on the ground plane, as presented in step- 3 offers a very good frequency response with a wide operating bandwidth. All the design parameters are depicted in Fig. 2, and the optimized values are listed in Table I.

Figure 4 conveyed the parametric study of the TVWS band antenna for four different paraments. These parameters has the significant effect on the frequency response than the other parameters. However, the final results are achieved by optimizing all the parameters. It can be observed from Fig. 4 that the antenna frequency can be adjusted based on the requirements by controlling the proposed design parameters.

Fig. 4.

Fig. 4

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Parametric study of Ant- 1 for the TVWS band, (a) f1, (b) f2, (c) L2, and (d) D2.

3D radiation pattern of the designed TVWS band antenna is illustrated in Fig. 5 at 0.5 GHz and 0.6 GHz. The antenna offers an ideal omnidirectional radiation pattern in the operating band. At the TVWS band the antenna offers a gain of more than 3.14 dBi within the functional frequency band, with a radiation efficiency of 92%. Deu to the omnidirectional radiation characteristics the designed TVWS antenna can act as an antenna sensor which will collect data from all directions. Additionally, the benefit of this TVWS band is that the signal can be sent from very long distances. Therefore, this antenna sensor will benefit rural communication where the numbers of base station are limited.

Fig. 5.

Fig. 5

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3D radiation behavior of the designed TVWS band element at 500 MHz and 600 MHz.

5.8 GHz band circular patch design

After getting good results for the TVWS band, a circular radiating element is designed on the same substrate for the 5.8 GHz ISM band as shown in Fig. 2. The idea is to fully utilize the substrate aperture and achieve multiple standard frequency bands. The radius R of the circular patch is calculated using Eq. (2) and Eq. (3)28. Here, the h is the substrate height, Inline graphic represent the substrate’s dielectric constant, and the targeted frequency is fr.

Subsequently the antenna radius R along with the feed position S3 from the center is optimized to achieve the optimum performance. Additionally, four rectangular slots are created on the designed circular patch, which offers a little improvement of the antenna directivity. The proposed circular patch and its 3D radiation performance at 5.8 GHz is illustrated in Fig. 6. Although the designed circular patch offers a unidirectional radiation pattern, it provides a wide coverage angel by having a half-power-beam-width (HPBW) of 112.5° and a radiation efficiency of 94%. Due to the wide coverage angel with high gain, this circular patch can be used as an efficient sensor for the 5.8 GHz band sensing and communications.

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Fig. 6.

Fig. 6

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Design and performance of the circular patch (a) schematic layout, and (b) 3D radiation pattern with gain value at 5.8 GHz.

The frequency response of this circular patch is mostly dependent on the parameter R and S3 as shown in Fig. 7. It can be observed from Fig. 7 (a) that the resonant center frequency of the circular patch can be controlled by optimizing the radius R of the circular patch. By increasing the value of R, the center frequency shifts from upper band to the lower band. Similarly, by decreasing the values of R the circular patch can be tuned for the upper frequency band. Additionally, by controlling parameter S3, which represents the position of the feeding of the circular patch from the center, performance of the resonance can be improved. The parametric study for S3 is presented in Fig. 7 (b). The finalized parameter values of this circular patch are listed above in Table I. The proposed design of this circular patch yields an operating bandwidth of 330 MHz covering both 5.8 GHz ISM band and the 5.9 GHz vehicle to everything (V2X) band.

Fig. 7.

Fig. 7

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Parametric study and frequency response of Ant- 2 for the 5.8 GHz band for different parameters (a) R, and (b) S3.

Wideband 5G Millimeter-Wave 2-Port MIMO design

To support the 5G millimeter-wave communication, a 2-port multiple-input multiple-output (MIMO) configuration is designed on the right side of the substrate as shown in Fig. 2. Initially Ant- 3 is designed for a wideband operating frequency from 23.02 GHz to 30.37 GHz. While Eq. (1) is utilized to obtain the width of the Ant- 3. After satisfying the performance of Ant- 3 an identical structure is created very near to Ant- 3 which is denoted as Ant- 4. The distance between Ant- 3 and Ant- 4 is 5 mm. In this work we kept the Ant- 3 and Ant- 4 as close as possible to show that many more millimeter-wave elements can be integrated on the right side of the substrate. To maintain high MIMO isolation with lower element spacing, a novel decoupling structure, parasitic stub with cavity vias is proposed and implemented. The design stages of the proposed decoupling structure are conveyed in Fig. 8.

Fig. 8.

Fig. 8

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Different design stages of the proposed decoupling structure of the 2-port MIMO elements for the 5G millimeter-wave band.

The transmission coefficient of the 2-port 5G MIMO for the different design stages is presented in Fig. 9. The others performance parameters including reflection coefficient, radiation pattern, and gain of the proposed 2-port MIMO elements are discussed later in the Antenna Results section. Here only the transmission coefficient and surface current are studied to show the effectiveness of the proposed decoupling structure. It can be observed from the transmission coefficient of different design stages of the decoupling structure in Fig. 9 that the proposed decoupling structure offers a significant isolation between the MIMO elements. Absolute value of the transmission coefficient is referring to the isolation between the MIMO elements. Without the decoupling structure as in Step- 1, the MIMO elements show a low minimum isolation of around 16 dB within the functional band. While with the parasitic element an improved minimum isolation of 19 dB is obtained. And with the proposed decoupling structure, parasitic stub with cavity vias, offers a very high minimum isolation of more than 26.4 dB within the operating frequency band.

Fig. 9.

Fig. 9

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Transmission coefficient of the 2-port MIMO elements for the different decoupling structures.

The surface current of the MIMO elements for with and without the proposed decoupling structures is studied and displayed in Fig. 10 to show the effectiveness of the proposed isolation enhancement method, while port of Ant- 3 is excited. Without the decoupling structure the Ant- 4 is affected by the current of Ant- 3. On the other hand, with the proposed decoupling structure, parasitic stub with cavity vias, the Ant- 4 shows very negligible influence due to the excitation of Ant- 3. Thus, a high isolation between the MIMO elements is achieved.

Fig. 10.

Fig. 10

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Surface current behavior of the 2-port MIMO elements at 28 GHz with and without the decoupling structure while Ant- 3 is excited.

Mutual coupling between all ports

The mutual coupling of all ports of the proposed shared-aperture antenna is presented in Fig. 11. The absolute value of the mutual coupling also refers as the port isolation. It can be seen that the coupling between the Ant- 3 and Ant- 4 is the maximum among the antenna ports. Without the proposed decoupling structure between Ant- 3 and Ant- 4, the coupling was too high which is shown earlier in Fig. 9. It can be observed from the Fig. 11 that the isolation among all the others ports are less than 32 dB.

Fig. 11.

Fig. 11

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Mutual coupling between all antenna ports; Ant- 1, Ant- 2, Ant- 3, and Ant- 4.

Performance of the proposed antenna sensor

The finalized simulated and measured results of the proposed shared-aperture multi-port antenna sensor are presented in this section. While the prototype of the proposed shared-aperture multi-port antenna sensor is displayed in Fig. 12. All the S-parameters are measured using Keysight frequency measurement equipment in open environments. While the far-field characterization is done by a commercial company in anechoic chambers29. For Ant- 1 and Ant- 2 in low frequency chamber, while the radiation behavior of Ant- 3 and Ant- 4 is characterized in a millimeter-wave high frequency chamber.

Fig. 12.

Fig. 12

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Prototype of the proposed shared-aperture multi-port antenna sensor.

Characteristic analysis of the Ant- 1

Reflection coefficient

The simulated and measured frequency response of the Ant- 1 of the proposed shared-aperture multi-port antenna sensor in terms of reflection coefficient is presented in Fig. 13(a), while Fig. 13(b) contains the reflection coefficient of Ant- 2. It can be observed from Fig. 13 (a) that the Ant- 1 offers a very wide operating bandwidth (S11<–10 dB) of more than 840 MHz (from 0.467 GHz to 1.31 GHz). Which covers the entire TVWS band (between 470 MHz and 780 MHz). Additionally, the Ant- 1 also covers the L2 (1227.6 MHz), L5 (1176 MHz) GPS satellite bands, and 1.2 GHz satellite band. The operating frequency of Ant- 1 makes it a good fit to perform as an antenna sensor to sense multiple broadcast signal including, TVWS, GPS and satellite signals.

Fig. 13.

Fig. 13

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Frequency response of Ant- 1 and Ant- 2 for both simulation and measurement (a) Ant- 1, and (b) Ant- 2.

Radiation behavior and sensing capabilities of Ant- 1

To check the suitability of the proposed multi-port antenna sensor, the radiation characteristics of all ports are measured. The radiation behavior characterization setup for Ant- 1 is displayed in Fig. 14. As the antenna will be act as a sensor in actual applications, the proposed antenna is set as an receiver and a standard horn antenna is used as an transmitter in the measurement setup. The positioner rotate the antenna 360° at both E and H plane. It can be seen from the measured antenna radiation pattern performance in Fig. 15 that the Ant- 1 offers a omnidirectional radiation pattern with a gain of 3.7 dBi at 0.6 GHz, respectively. Within the operating band the Ant- 1 shows similar omnidirectional radiation pattern. With this omnidirectional radiation pattern the Ant- 1 can sense signal from all the direction within the operating frequency band between 0.467 GHz and 1.31 GHz.

Fig. 14.

Fig. 14

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Radiation measurement setup for different antenna ports in the anechoic chamber (a) port- 1, and (b) port- 2.

Fig. 15.

Fig. 15

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Radiation behavior of Ant- 1 at 0.6 GHz (a) measured 3D radiation pattern and (b) 1D polar radiation pattern.

Characteristic analysis of the Ant- 2

Reflection coefficient

The Ant- 2 of the proposed antenna sensor offers–10 dB impedance bandwidth from 5.63 GHz to 5.96 as shown above in Fig. 13 (b); covering both the 5.8 GHz ISM band and the 5.9 GHz V2X band. The Ant- 2 of the proposed antenna sensor can sense any signal within the offered operating band. Similarly it can communicate with the users by sending data using the V2X and ISM band.

Radiation behavior and sensing capabilities of Ant- 2

The radiation characterization of Ant- 2 is similar to Ant- 1 as shown in Fig. 14 above. The Ant- 2 shows a unidirectional radiation patten. The radiation behavior of Ant- 2 at 5.8 GHz is depicted in Fig. 16. At 5.8 GHz the Ant- 2 offers a HPBW of more than 112.5° with a gain of 6.76 dBi. Within the functional band the Ant- 2 shows similar radiation performance. The wide beam angle and high gain of the Ant- 2 makes it an efficient tool for the 5.8 GHz ISM and 5.9 GHz V2X band sensing and communications.

Fig. 16.

Fig. 16

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Radiation behavior of Ant- 2 at 5.8 GHz (a) measured 3D radiation pattern and (b) 1D polar radiation pattern.

Characteristic analysis of the Ant- 3 and Ant- 4

Reflection and transmission coefficient

The 2-port MIMO elements of the proposed antenna sensor which is presented as Ant- 3 and Ant- 4 yields a wide operating bandwidth from 23.02 GHz to 30.37 GHz. The frequency response of Ant- 3 and Ant- 4 is presented in Fig. 17(a). The Ant- 3 and Ant- 4 shows identical frequency response. The simulation and measured results offers a little mismatch due to the connector and cable losses. The offered operating bandwidth of the designed 2-port MIMO system makes it an efficient solution for the 5G millimeter-wave sensing and communications.

Fig. 17.

Fig. 17

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Results of Ant- 3 and Ant- 4 (a) reflection coefficient, and (b) transmission coefficient.

The transmission coefficient (Sij parameters) of the designed 2-port MIMO system at the 5G millimeter-wave band is presented in Fig. 17(b). By utilizing the proposed decoupling structure, parasitic stub with cavity vias, the 2-port MIMO system shows a very low mutual coupling less than − 26.4 dB within the functional bandwidth, which ensure a high element isolation between the MIMO elements. Due to the high isolation, the proposed MIMO system offers excellent MIMO performances.

Radiation behavior and sensing capabilities

The radiation characterization setup of the designed 2-port MIMO system for the 5G millimeter-wave band is depicted in Fig. 18. In the measurement setup the proposed antenna sensor act as a receiver whereas the Ant- 3 or Ant- 4 will sense signal transmitted from a standard horn antenna. From the measurement results the suitability of the designed MIMO system can be observed for the sensing and wireless communication.

Fig. 18.

Fig. 18

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Radiation characterization setup for the designed 2-port MIMO system (Ant- 3 and Ant- 4) in an anechoic chamber (a) side view, (b) front view.

The radiation behavior of the Ant- 3 and Ant- 4 is presented in Fig. 19. These antennas demonstrate a similar radiation characteristics. These antennas offers a peak gain of 7.68 dBi with an unidirectional radiation. The overall radiation characteristics of Ant- 3 and Ant- 4 allows them to perform efficiently for the 5G millimeter-wave band. Moreover, the simulation result confirms a radiation efficiency of more than 95.6%.

Fig. 19.

Fig. 19

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Radiation behavior of Ant- 3 and Ant- 4 at different frequencies.

MIMO characteristics

The diversity performances of the designed 2-port MIMO system are conveyed in Fig. 20. While in Fig. 20(a) contains the envelope correlation coefficient (ECC) and diversity gain (DG). And the mean effective gain (MEG) and total active reflection coefficient (TARC) is presented in Fig. 20(b).

Fig. 20.

Fig. 20

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MIMO performances of the designed 2-port MIMO system for 5G millimeter-wave band (a) ECC and DG, and (b) MEG and TARC.

The ECC results of the presented 2-port MIMO system is calculated using Eq. (4), and Eq. (5) from the S-parameters and radiation pattern, respectively30. For this 2-port MIMO system i, j= 1, 2. Excellent element isolation and minimal correlation are guaranteed by a low ECC level, which improves MIMO capabilities31–34. The designed MIMO 2-port system shows a ECC level less than 0.0015 within the passband.

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The DG demonstrates how the diversity scheme of MIMO elements affects the radiated power, which can be calculated using Eq. (6)30. The designed 2-port MIMO system shows an excellent DG performance near to the ideal value of 10 dB.

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Form Fig. 20(b) it can be seen than the presented 2-port MIMO system also shows an excellent MEG and TARC performance. The acceptable standard MEG value should be between − 3 and − 12 dB30, while the presented 2-port MIMO system yields a MEG value of abound − 3.5 dB. Additionally, it offers a good TARC value of less than − 12 dB within the operating band.

The channel capacity loss (CCL) of the 2-port millimeter-wave MIMO system is displayed in Fig. 21. The CCL metric quantifies the loss of bits that may occur during transmission35,36. The maximum allowable CCL value in any environment is 0.4 bits/s/Hz to ensure the good quality of the communication link36. It can be observed from Fig. 21 that the designed 2-port MIMO antenna system for the 5G millimeter-wave communication yields a CCL value less than 0.2 bits/s/Hz within the operating frequency band.

Fig. 21.

Fig. 21

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CCL performance of the of the designed 2-port MIMO system for 5G millimeter-wave band.

Performance comparison

Performance comparison of the proposed shared-aperture multi-port antenna sensors antenna with other shared-aperture antennas is presented in Table 2. It can be observed that, only the proposed antenna use a single substrate layer, while all other reported shared aperture antennas required multiple substrate layers. Antennas reported in21,26occupy less antenna profile, however they suffer from either complex design procedure21or do not offer any band at Sub- 6 GHz26. Moreover, none of the reported antennas20–26 offers TVWS frequency band for the long-distance communication capabilities specially in rural areas where the number of base stations is limited. Additionally, the proposed antenna offers a very good port isolation of 26.4 dB with a single layer configuration. Overall performance of the proposed share-aperture multi-port antenna sensor, specially the three operating frequency band including the TVWS band makes it a viable solution for the sensing and communication in rural areas.

Table 2.

Performance comparison with other shared-aperture antennas.

Ref. Total Profile (mm) Sub- 6 GHz
/5G mmWave		 Operating Bands
/TVWS Band		 Bandwidth
(GHz)		 Isolation
(dB)		 Substrate Layers
20 3.45 Yes/Yes Two/No

3.38–3.64

26.4–29.8

 40 Quadruple
21 0.559 Yes/Yes Four/No

2.55–2.62

4.74–5.24

26.5–27.4

37.4–38.6

 35 Double
22 32.54 Yes/Yes Two/No

5.3–5.49

22.3–26.2

 30 Triple
23 19.4 Yes/No Two/No

4–8.6

12–20

 25 Double
24 > 20 Yes/No Three/No

1.85–2.15

3.4–3.6

5.4–5.6

 15 Triple
25 53.2 Yes/No Two/No

0.77–1.06

2.2–6.6

 20 Quadruple
26 0.749 No/Yes Two/No

27.7–33.5

54.1–63.2

 30 Quintuple
Prop. 1.524 Yes/Yes Three/Yes

0.046–1.31

5.63–5.96

23.02–30.37

26.4 Single
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Conclusion

A shared aperture muti-port antenna sensor is presented for three different operating frequencies covering both Sub- 6 GHz and 5G millimeter-wave bands to accommodate the antenna demand for rural sensing and seamless connectivity. The proposed antenna sensor is created on a 60-mil thick Taconic TLY- 5 substrate having a relative permittivity of 2.2 and loss tangent of 0.0009. The simulated and measured findings show that the proposed antenna sensor can cover TV-white-space (TVWS) frequency band (0.467–1.31 GHz), 5.8 GHz ISM band (5.63–5.96 GHz), and the 5G millimeter-wave frequency band (23.02–30.37 GHz). At the TVWS band the antenna offers a gain of more than 3.14 dBi with an omnidirectional radiation pattern. Deu to the omnidirectional radiation characteristics the proposed antenna at TVWS can act as an antenna sensor which will collect data from all directions. At the 5.8 GHz band the antenna offers a unidirectional radiation pattern with an HPBW of more than 112.5°. The wide beam angle and high gain (6.76 dBi) of the antenna at 5.8 GHz band makes it an efficient tool for the 5.8 GHz ISM and 5.9 GHz V2X band sensing and communications. Additionally, the 2-port MIMO for the 5G millimeter-wave sensing and communications also offers excellent MIMO diversity performances with a gain of 7.68 dBi. Overall performance of the proposed share-aperture multi-port antenna sensor, especially the three operating frequency band including the TVWS band makes it a viable solution for the sensing and communication in rural areas.

Acknowledgements

This work was supported by Korea Institute for Advancement of Technology (KIAT) grant funded by the Korea Government (MOTIE) (P0024169, Development of RIC (Regional Innovation Cluster)). Additionally this work was also supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. RS-2025 - 00519330).

Author contributions

Conceptualization, M.A.S.; writing—original draft preparation, M.A.S.; writing—review and editing, S.L, M.A.S., D.C., M.S. and N.K.; methodology, M.A.S, J.L. and D.S.; formal analysis, M.A.S., D.C., M.S. and S.L; investigation, D.S, J.L., M.S. and N.K.; visualization, M.A.S., D.C. and N.H.; project administration, S.L. and N.K. All authors have read and agreed to the submitted version of the manuscript.

Data availability

The presented paper contains all the data required for evaluating the findings of this research. The corresponding author can be contacted for more data regarding this work.

Declarations

Competing interests

The authors declare no competing interests.

Footnotes

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Contributor Information

Sang-Min Lee, Email: leesm@ut.ac.kr.

Nam Kim, Email: namkim@chungbuk.ac.kr.

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Data Availability Statement

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