Siw-slot antipodal vivaldi antenna for x band applications

Abstract

The invention relates to the development in the system of highly efficient siw-slot antipodal Vivaldi antenna for x band applications which performs the process of providing propagation within the transmission channel (receiver) by collecting electromagnetic waves propagating in space or the process of emitting electromagnetic waves into the space (transmitter) for communication systems.

Description

[0001] SIW-SLOT ANTIPODAL VIVALDI ANTENNA FOR X BAND APPLICATIONS

[0002] TECHNICAL FIELD

[0003] The invention relates to the development in the system of highly efficient siw-slot antipodal Vivaldi antenna for x band applications which performs the process of providing propagation within the transmission channel (receiver) by collecting electromagnetic waves propagating in space or the process of emitting electromagnetic waves into the space (transmitter) for communication systems.

[0004] STATE OF ART

[0005] The coplanar Vivaldi antenna included in the state of the art consists of three basic parts. The antenna can be divided into three parts: the microstrip line where the signal is carried, the part where the signal passes from the microstrip line to the cavity structure and the exponential curves where the radiation takes place. Exponential radiation curves make it easy to match the input impedance to the output impedance. There is a microstrip line structure in the input part. The input impedance is usually made to match a 50 0 line. The output impedance of the antenna is designed to match the air impedance of 120 IT (377 Q). Since the exponential curves from the topology of the Vivaldi antenna act as the matching, the input and output impedance matching of the antenna is ideal.

[0006] By means of different parameters on the antenna, the antenna performance can be adjusted as desired. The antenna length allows the operation frequency to be adjusted. Generally, in antenna designs, the length or dimensions of the antenna are the most important parameters in adjusting the frequency. For example, antenna dimensions decrease as the frequency increases. This is because the wavelength decreases with increasing frequency.

[0007] In the coplanar vivaldi antenna, the transition part from the microstrip line to the cavity structure is a very important parameter. By means of this part, the signal generated at the input of the antenna is transferred to the radiation plane. The antenna is critical for the radiation pattern and return loss. The aperture of the coplanar vivaldi antenna and the curvature of the exponential curves greatly affect the return loss.

[0008] The coplanar vivaldi antenna consists of two conductor planes. These two conductor planes are symmetrical to each other and there is a dielectric material between them. The two conductors in the coplanar vivaldi antenna have different functions. One of them is the feed line and the other one is the radiation plane. As a result of the feed from the microstrip line, the current passes to the other conductor, the radiation plane, where it begins to radiate symmetrically.

[0009] Traditional coplanar vivaldi antennas have problems such as low bandwidth, low gain, large size and polarization.

[0010] By means of different parameters on the traditional Vivaldi antenna, the antenna performance can be adjusted as desired. The antenna length allows the operation frequency to be adjusted. Generally, in antenna designs, the length or dimensions of the antenna are the most important parameters in adjusting the frequency. For example, antenna dimensions decrease as the frequency increases. This is because the wavelength decreases with increasing frequency.

[0011] With the SIW structure added to the antenna geometry and the slots opened on the antenna surface, the size of the antenna is reduced with respect to the wavelength and the gain is increased.

[0012] Planar structures such as microstrip transmission lines, coplanar waveguides allow small size designs and have low manufacturing costs. However, they have high losses compared to conventional waveguides.

[0013] US patent with Publication number US6518931 B1 describes a notch antenna configuration.

[0014] Chinese document with publication number CN104852131 A is an asymmetric Vivaldi antenna configuration. The Chinese document with priority number CN201711165281 A discloses a microstrip high gain antenna configuration comprising a vivaldi radiation unit, an elliptical metal patch and a semi-elliptical dielectric substrate.

[0015] DESCRIPTION OF THE INVENTION

[0016] In order to fill the performance gap between planar and non-planar structures with the invention, Waveguides Integrated on a Dielectric Base (DBD) that combine the best features of both structures have been developed.

[0017] One of the aims of the invention is to provide DBDs having structures realized in a planar dielectric base with periodically ordered metallic through-holes connected to the upper and lower ground planes.

[0018] Another aim of the invention is to increase the antenna bandwidth by adding a DBD-SIW structure so that it can operate in the 8-12GHz frequency band.

[0019] Another aim of the invention is to design an antenna with high gain characteristics as one of the most important elements of today's wireless communication systems.

[0020] Another aim of the invention is to have a high bandwidth and miniaturized design.

[0021] Another aim of the invention is to provide microstrip antennas that are easy to manufacture, small in volume and light weight, with low production costs.

[0022] Another aim of the invention is to be used as a receiver and transmitter in X band communication systems as an antenna model for a low-sized, lightweight, broadband antenna.

[0023] Another purpose of the invention is to be used in radar applications and satellite communication systems. DESCRIPTION OF FIGURES

[0024] Figure 1- Front and rear view of the antenna

[0025] Figure 2- Front view of the antenna

[0026] Figure 3- Rear view of the antenna

[0027] Figure 4- Cross-sectional view of the antenna

[0028] Figure 5- Via connection view of the antenna

[0029] Table 1- Return loss graph

[0030] Table 2- Maximum gain graph

[0031] REFERENCE LIST

[0032] 10- Front face of the antenna

[0033] 11- Feed line

[0034] 12- Slot layout

[0035] 13- SIW structure sequence

[0036] 14- Compatibility line

[0037] 15- Substrate material

[0038] 20- Rear face of the antenna

[0039] 21- Ground line

[0040] 22- Slot layout

[0041] 23- SIW structure sequence

[0042] 24- Compatibility line

[0043] DETAILED DESCRIPTION OF THE INVENTION

[0044] The front face of the invention consists of a front face (10) comprising feed line (11 ), slot layout of the antenna aperture (12), preferably consisting of 3 slots, protrusion-shaped and multiple, preferably 9, SIW sequences (13), exponential compatibility line (14) with concave structure, substrate material (15), preferably in sizes of 35.6mm x 38.6mm x 0.76mm and copper-coated on the top and bottom surface, The rear face of the invention consists of a rear face (20) comprising ground line (21 ), slot layout of the antenna aperture (22), preferably consisting of 3 slots, protrusion-shaped and multiple, preferably 9 SIW sequences (23) comprising the vias having the same structure with the front face, exponential compatibility line (24) with concave structure.

[0045] With the SIW structure sequences (13,23) added to the antenna geometry in the embodiment of the invention and the slots (12,22) opened on the antenna surface, the size of the antenna is reduced with respect to the wavelength and the gain is increased.

[0046] In the embodiment of the invention, DBDs are structures realized in a planar dielectric base with periodically ordered metallic through-holes connected to the upper and lower ground planes, the antenna bandwidth has been increased by adding a DBD-SIW structure, thus enabling the operation in the 8-12GHz frequency band.

[0047] The thickness of the copper and substrate material used in the copper and substrate material structure in the invention structure is preferably 0.035mm and the substrate material Droid RT5880 is positioned at the top and bottom parts of the copper. The height of the substrate used is variable and it is used preferably as 0.76mm.

[0048] Due to the broadband requirements in the embodiment of the invention, the S11 and gain of the antenna were improved by opening slots on the antenna, which is based on the coplanar Vivaldi antenna model compatible with X-band applications, and SIW structure is also added to the antenna to increase the antenna gain.

[0049] The Vivaldi antenna is preferably made of RT Droid5880 material (er=4.88, h=0.76mm) and designed to operate in the 8-12 GHz bandwidth.

[0050] Operation of the antipodal Vivaldi antenna embodiment The embodiment of the invention is an antipodal vivaldi antenna consisting of two conductor planes. These two conductor planes are symmetrical and have a dielectric material between them. The two conductors in the antipodal Vivaldi antenna have different functions. One of them is the feed line and the other one is the radiation plane. As a result of the feed from the microstrip line, the current passes to the other conductor, the radiation plane, where it begins to radiate symmetrically. Antipodal Vivaldi antenna has a microstrip line at the input part. The antenna is fed with a connector suitable for the operating frequency of the antenna. In the Vivaldi antenna, most of the current from the source is directed to the edges where the curves are located. The curves on the conductor planes are important for the radiation pattern. Therefore, they need to be well optimized for the desired radiation pattern. If microstrip transmission lines have planar structures such as coplanar waveguides, they allow for small size designs and have low manufacturing costs. However, they have high losses compared to conventional waveguides. To fill the performance gap between planar and non- planar structures, SIW has been developed, combining the best features of both structures. SIW is a planar dielectric base with periodically ordered metallic through-holes connected to the upper and lower ground planes. In order to improve the radiation pattern with the slot structures on the antenna, the radiating areas of the antenna are controlled. The antenna currents are important not only in the radiating slot region but also in the outer parts of the antenna. Therefore, the antenna gain is increased by damping the unwanted currents by cutting the edges. In fact, this only allows currents to radiate in the narrowing region and blocks other currents.

[0051] Industrial Applicability

[0052] The dxf or gerber file of the antenna model is loaded into the printed circuit device (device that engraves the paths on the substrate material). Our rt5880 substrate material is placed on the printed circuit device. The placed material is defined in the software of the device. The antenna production file (file containing antenna geometry information) is loaded on the software on the device. In the relevant software, the front face, back face, size of the antenna, areas where copper will remain, areas where copper will be engraved, and the diameter and position of the SIW holes are determined. After this stage, the device is switched on and the relevant engravings are made on the substrate and SIW holes are opened. The antenna is removed from the substrate material removed from the device. After removal, the inner coating of the SIW holes is performed. In this part, the inside of the holes are coated with solder or copper. After the inside of the hole is coated, a 50ohm SMA connector is soldered to our antenna and it is made ready for use.

Claims

CLAIMS1. A siw-slot antipodal vivaldi antenna for x band applications wherein it consists of a front face (10) comprising feed line (11 ), slot layout of the antenna aperture (12), preferably consisting of 3 slots, protrusion-shaped and multiple, preferably 9, SIW sequences (13), exponential compatibility line (14) with concave structure, substrate material (15), preferably in sizes of 35.6mm x 38.6mm x 0.76mm and copper-coated on the top and bottom surface, and a rear face (20) comprising ground line (21 ), slot layout of the antenna aperture (22), preferably consisting of 3 slots, protrusion-shaped and multiple, preferably 9 SIW sequences (23) comprising the vias having the same structure with the front face, exponential compatibility line (24) with concave structure.

2. An antipodal vivaldi antenna according to Claim 1 , wherein the antenna comprises the SIW structure sequences (13,23) added to the antenna geometry and the slots (12,22) opened on the antenna surface which reduce the size of the antenna with respect to the wavelength and increase the gain.

3. An antipodal vivaldi antenna according to Claim 1 , wherein in the embodiment of the invention, DBDs are structures realized in a planar dielectric base with periodically ordered metallic through-holes connected to the upper and lower ground planes, the antenna bandwidth has been increased, thus preferably a DBD-SIW structure enabling the operation in the 8-12GHz frequency band is added.

4. An antipodal vivaldi antenna according to Claim 1 , wherein the thickness of the copper used in the copper and substrate material structure is preferably 0.035mm and the substrate material Droid RT5880 is positioned at the top and bottom parts of the copper, the height of the substrate used is variable and it is preferably 0.76mm.

5. An antipodal vivaldi antenna according to Claim 1 , characterized in that due to the broadband requirements, slots are opened on the antenna which are created on the coplanar Vivaldi antenna model compatible with X-band applications, and which improve the S11 and gain of the antenna.

6. An antipodal vivaldi antenna according to any one of the Claims 1 ,2 or 3, wherein SIW structure is also added to the antenna to increase the antenna gain.

7. An antipodal vivaldi antenna according to any one of the Claims 1 or 6, wherein it is preferably made of RT Droid5880 material with values of er=4.88, h=0.76mm and it operates in the 8-12 GHz bandwidth.

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