Description:Field of Invention
The present invention pertains to an antenna designed for the reception or transmission of electromagnetic waves exhibiting a broader passband which is essential for 5G systems. The antenna exhibits a stepped rectangular shape, making it well-suited for production through printed circuit techniques. This characteristic enables the antenna to be cost-effective and lightweight. The antenna of this invention shows high bandwidth in comparison to existing printed circuit antennas, while also demonstrating a moderate level of gain. The invention also pertains to several desired applications of the antenna, depending on the resulting configuration. The invention is also concerned with a beneficial technique for manufacturing such an antenna. The invention can be effectively utilized in the context of mass-production equipment not only for fifth-generation systems but also for mobile terrestrial terminals or satellite communication television receivers.
The objectives of this invention

The invention aims to improve the performance of microstrip patch antennae in terms of bandwidth, gain, radiation pattern, and reflection coefficient. The objective of this invention is to present a planar antenna that possesses a broad frequency pass-band and moderate gain. The primary objectives of this study are to provide a cost-effective manufacturing solution and to enhance the radiation characteristics of the antenna feasible for 5G systems. The rationale behind achieving moderate gain is elucidated by the advantages of minimizing the number of feed points for the antennas, thereby reducing the complexity and potential losses inherent in arrays of antenna elements. This technology can be effectively utilized in the context of mass-production equipment for mobile terrestrial terminals or satellite communication television receivers. The invention also pertains to a beneficial technique for manufacturing said antenna.The designed antenna has multiple frequency bands and resonates at both lower band (18 GHz) and higher band (38 GHz). It also possesses enhanced bandwidth in both frequency bands with significant improvement in the gain.
Background of the invention
The modern smartphones require exceptionally high bandwidth, 5G communication technology is seen as a revolution in the wireless communication industry. This rapid development inspires academics to develop communication technologies, whether in software or hardware. Antenna design is also regarded as a critical area that necessitates continual research to support 5G wireless communication networks. The main purpose of this invention is to design and construct a wideband, multi-band, and significant gain microstrip antenna for 5G systems that meet all of the requirements of modern wireless communication networks. The suggested antennas are designed to operate at two distinct frequencies: 15 GHz and 40 GHz covering Ku and Ka bands respectively.5G frequency bands are FR1 and FR2. FR1 (4.1 GHz to 7.125 GHz) carries most standard cellular mobile communications traffic, while FR2 (24.25 GHz to 52.6 GHz) focuses on short-range, high-data-rate capabilities. Due to their tiny wavelengths, these high-frequency bands are called "mm-Wave." Although mm-Wave bands go up to 300 GHz, 24 to 100 GHz will be used for 5G. Today, we employ nearly the entire radio frequency band below 6 GHz. The growing number of gadgets with high traffic demands will soon exhaust our current network capacity (H. -C. Huang, 2018 International Workshop on Antenna Technology (iWAT). As the need for spectrum to support future advancements grows, we are forced to use bandwidth over 6 GHz.To fix the dimensions of the antenna, there are many design approaches in the literature. Most antenna designers prefer the parametric analysis method. Optimized specifications can be achieved with this method.One of the most preferred methods to improve the radiation characteristics is the Defective Ground Structure (DGS) method. The ground plane is essentially subjected to deformation in such a way that the inductive and capacitive characteristics must be changed[Jayendra Kumar, Microwave And Optical Technology Letters / Vol. 58, No. 6, June 2016]. The resonating frequency may vary with the DGS method. This method is preferred as it provides better results and ease.
Plenty of methods have been proposed by researchers to change the radiation performance of any antenna, particularly to improve the bandwidth of an antenna for 5G communication systems.A new microwave spectrum (3.3 - 4.2 GHz) and more efficient use of millimeter-wave frequency band bandwidth may meet the 5G needs (24 -100 GHz) [J.G.Andrews et.al, IEEE J. Commun., vol. 32, pp. 1065–1082, June 2014]. Among these high-frequency bands, the 26 GHz and 28 GHz bands give more attention and give superior bandwidth, resulting in fast data throughput and minimal latency [Risto Valkonen, IEEE/MTT-S, Int.Microw.Symp., Pennsylvania, pp. 1334–1337,2018]. Federal Communications Commission (FCC) reallocated local multi-point block distribution service A1 (LMDS-A1), with an overall width of 850 MHz, to free up a frequency range between 27.5 and 28.35 GHz, which now includes the 28 GHz band. The SHF band spans 3 to 30 GHz frequency, whereas the EHF (millimeter-wave range) spans 30 to 300 GHz frequency. Because SHF and EHF radio waves travel identically, the 3–300 GHz spectrum is millimeter-wave bands with 1–100 mm wavelengths [Mohsen Khalily Rahim Tafazolli et.al, IEEE Trans. Antennas Propag., vol 67, pp. 1–8, 2018]. In [Khalily, M et.al, IEEE Tran. Ant. Propag. Lett. 2018, 66, 4641–4647], The Urban area (38 GHz) and N Y University (28 GHz) were the study’s primary data sources. With a cell radius of just 200 meters, base stations can provide uninterrupted coverage at 28 and 38 GHz. At present, we use 5GHz in present mobile phones. Since frequency is inversely related to the wavelength, extremely high frequency (EHF) results in a very low wavelength. Wavelengths between 1mm and 10 mm are also known as millimeter waves. Radio waves that are currently used by smartphones are in centimeters which is much larger than the mm waves. So far, these mm waves are used in radar systems and satellites. With 5G coming into existence, there can be various application that has the potential to revolutionize this world [Venkatesh, et.al, (2019), Cell and tissue research, 377, 125-151.]. Based on the observation from the literature [Ravi, K.C.; Kumar, J., Iran. J. 7Sci. Technol. Trans. Electr. Eng. 2022, 46, 311–317], [ C.A.Balanis, Wiley, 2005 ]a stepped rectangular patch antenna is invented and the DGS method is implemented to enhance the bandwidth.
Details of Prior Art
Virtual reality (VR) vs Augmented reality (AR), Artificial Intelligence (AI), Internet of Things (IoT), and driverless cars are the major applications of 5G systems where bandwidth plays a crucial role. Rampart type antenna is proposed to improve the bandwidth but the design complexity is more (US2537191A). As communication technology advances, numerous wireless items are manufactured in large quantities. Bluetooth was recently designed to facilitate communication between electronic devices such as computers, printers, digital cameras, refrigerators, TVs, air conditioners, and other wireless gadgets. Bluetooth's ISM (Industrial Scientific Medical) band has a frequency range of 2.4 to 2.4835 GHz. If more wireless items use the Bluetooth system, the ISM's single frequency band will not be able to accommodate the high volume and transmission rate. The same thing happens in other ISM 2.4 GHz wireless communication systems, such as WLAN (wireless local area network) and HomeRF (Home radio frequency)- (US6788257B2). As an antenna engineer is aware that microstrip patch antenna is low profile and low cost, but has narrow bandwidth. Therefore, it’s a challenging task to enhance the bandwidth of any microstrip antenna. This invention relates to antennas, and more specifically to antennas for emitting or receiving directions. Such antenna structures are designed for installation in the hull of a ship or aircraft, with the cavity structure located inside the hull and the slot opening covered with an electrically transparent sheet of insulating material used with the hull (US2885676). As a result, one of the invention's goals is to create a portable microwave antenna capable of projecting a unidirectional wide beam of radiofrequency radiation from a small, hand-held source. A dual frequency cavity-backed antenna is invented. The innovation seeks to solve the challenge of providing a compact, lightweight flashlight-style microwave radiator capable of being hand-held and projecting beams of invisible microwave energy in much the same way an ordinary flashlight projects visible light. Furthermore, depending on the various applications for which the device may be used, the microwave flashlight of the invention is capable of projecting two or more beams of different wavelengths and frequencies along a common central axis, either independently or simultaneously, or alternately. The invention's gadget is beneficial for field testing various types of microwave gear by providing a portable supply of microwave energy. (US3312976A).

Summary of Invention
This invention describes a bandwidth enhancement approach for improving radiation parameters such as gain, pattern, and reflection coefficient, all of which are required for 5G mobile communication systems. The defective structure is a very effective strategy for improving antenna performance that is suitable for fifth-generation communication systems. A stepped rectangular form is used to achieve the resonant frequency, and the DGS technique is used to increase the bandwidth. Better results are obtained with little changes to the antenna construction. The proposed antenna concept is conformal, simple to integrate into complicated networks, and may be used in aviation applications, airborne ships, and mobile phones, among other things.
Detailed description of the invention
Figure.1 shows the layout of the primary antenna designed to operate at 28 GHz frequency. Initially, the dimensions of the substrate, ground plane, patch, and quarter wave transformer are calculated using the formulas given in Balani'stextbook. A simple rectangular patch antenna is designed as a part of the primary design. The designed model has been simulated using HFSS.
Design of rectangular microstrip patch array for 28 GHz: ?_r=4.4, h=0.8 mm
Theoretical Calculations:

Dimensions of the patch antenna can be calculated from the following formulae:

Width of the patch (W_p):

W_p=v/?2f?_r v(2/(?_r+1)) (1)

Where v is the velocity of the electromagnetic wave

f_r is the resonant frequency

?_ris the relative permittivity

Therefore, the width of the patch (W_p) = 5.015mm (optimized to 5.4 mm)

Length of the patch (L_p): The patch's length is calculated by subtracting the effective length from the expanded length.

L_p=L_eff-2 ?L (2)

Where L_eff is the effective length of the patch and is given by

L_eff= v/?2f?_(rv(?_reff )) (3)

Where ?_reff is the effective relative permittivity and is given by

?_reff=(?_r+1)/2+(?_r-1)/2 [1+12 h/W_p ]^((-1)/2) (4)

And ? Lis theextended length due to the fringing effect and is given by

? L=0.412 h (?_reff+0.3)(W_p/h+0.264)/(?_reff-0.258)(W_p/h+0.8) (5)

Therefore, Length of the patch (L_p) = 2.095mm (optimized to 2.4 mm)

Substrate dimensions:

Length of substrate (L_sub) = L_p+6h = 7.2 mm (optimized to 5 mm) (6)
width of the substrate (W_sub) = W_p+6h= 10.2mm (optimized to 11 mm) (7)

feed length = ?/2=3.2135 mm (1mm chosen) (8)

feed width (50O line) = (377/((v(?_r ))Z_o ) – 2) h; [Z_o=50 ohms] (9)

= 2.4667 mm (1mm chosen)

feed width (100O line) = (377/((v(?_r ))Z_o ) – 2) h; [Z_o=100 ohms] (10)

=0.43338 mm (chosen value 1mm)

To optimize the dimensions of the antenna, the parametric analysis method is adopted. Initially, deviation from resonating frequency is observed. The reflection coefficient is also not significant. The first layout is in the figure.1 shows the primary antenna (Antenna-1) with dimensions. The entire design is divided into four designs, the first three (antenna-1,2, and 3) are primary models. The fourth design is the proposed model for further analysis.
A variety of strategies have been published for improving the parameters of traditional microstrip antennas, including EBG, PBG, Metamaterial, and so on. Because of its easy structural design, the microwave component with DGS has acquired favor among all ways for increasing parameters. DGS are etched grooves or faults on the ground plane of a microstrip circuit. After implementing DGS method, the resonating frequency is significant and reflection coefficient also has considerable value. The bandwidth also improved from 1.8 GHz to 8.44 GHz. The radiation pattern shows better characteristics compared to that of primary antenna when not applied DGS method. Then for further analysis, to obtain better radiation characteristics that is to meet the major objective of the invention is the to enhance bandwidth of the antenna useful for 5G systems. To enhance the bandwidth, rectangular cut on four corners of the rectangular patch is made which changes the capacitive and inductive values and in turn changes fields on the patch. Hence the bandwidth has been enhanced more compared to the other first three models. Also, the directionality and the gain are improved correspondingly.
Brief Description of Drawing
The List ofFigures, which are illustrated exemplary embodiments of the invention.
Figure 1 Design flow chart.
Figure 2 Design flow of the antenna model.
Figure 3 Shows the Parametric analysis
Figure 4 Reflection coefficient curve of the 4 designs
Figure 5 Radiation pattern of the 4 designs.
Figure 6 3D polar plots of the antenna models
Detailed description of Drawing
As described above present invention relates to the multi-frequency bandwidth enhancement of a stepped rectangular patch antenna useful for 5G communication systems.Figure 2 shows the design flow diagram of the patch antenna divided into four different models.
The primary antenna is represented with A-1, and the model obtained after modification in the ground plane is represented by A2. The major modification is started by making the rectangular cut on either side of the rectangular patch with which A-3 is formed. Now the final iteration is made by removing the rectangular-shaped part on the bottom side of A-3 that form the proposed model.
The parametric analysis method is adopted to fix the dimensions of the antenna. The S11 curve obtained for different dimensions of the ground plane is shown in Figure 3.
Figure 4 shows thereflection coefficient curve of A-1, A-2, A-3, and proposed. From figure 3 it is observed that the proposed model resonates at multiple frequency (15 GHz, 26 GHz, 31. Ghz etc.) also the reflection coefficient value has been improved from 23. 52 dB to 46.25 dB. The bandwidth also has been improved for the proposed model from 1.8 GHz to 14.35 GHz.
Figure 5 shows the 2D radiation pattern of the four models. Among all, the gain has been improved from 3.3 to 4.3 dB. The pattern is bidirectional for the primary model. The directionality of the proposed model becomes multi-directionalwhich means radiation can be directed towards the specific region that covers 360 degrees. This is advantageous as per as 5G communication systems are concerned. Therefore, the proposed model can provide better bandwidth in two important frequency bands (18 GHz and 38 GHz) and better radiation pattern characteristics.
Figure 6 shows the 3D polar radiation pattern of the primary and proposed models. From this, it is observed that the gain has been improved from 3.3 dB to 4.3 dB.
5 Claims & 6 Figures , Claims:The following claims define the scope of the invention:
Claims:
1. A very compact low profile easy to fabricate multiband wide bandwidth stepped rectangular patch antenna is proposed for the invention. It is useful for 5G communication systems.
a) The dimensions of the rectangular patch are calculated from the equations given in Balani’s textbook.This antenna is very compact and easy to fabricate and less complex structure.
b) Using the optometricanalysis method, the dimensions of the patch, quarter wave transformer, substrate-ground, and feed dimensions are designed. Regular methods have been adopted for the analysis.
c) Next, with the help of the HFSS tool simulation is done for different iterations.
2. As per Claim 1, the reflection coefficient plot for four different models has been simulated.
3. As per Claim 1, the obtained S11 results have been compared for the four different models like A-1 (-31 dB), A-2(-26.4 dB), A-3(-23dB), and proposed (-41 dB).
4. As per Claim 1, The bandwidth of the four models has been calculated: Bandwidth for A1 is 1.89 GHz, for A2 is 8.44 GHz, for A-3 is 7.89 Ghz, and for the proposed model is 9.29 GHz (lower band) and 14.35 GHz (upper band).
5. As mentioned in Claim1, the gain has been improved from 3.3 dB to 4.3 dB