Projects:2021s1-13113 Miniaturised metasurface antennas - Revision history

A1748545 at 15:20, 24 October 2021

2021-10-24T15:20:16Z

A1748545 at 15:19, 24 October 2021

2021-10-24T15:19:41Z

A1748545 at 15:19, 24 October 2021

2021-10-24T15:19:27Z

A1748545 at 15:19, 24 October 2021

2021-10-24T15:19:08Z

A1748545 at 15:16, 24 October 2021

2021-10-24T15:16:54Z

A1748545 at 15:11, 24 October 2021

2021-10-24T15:11:45Z

A1744012: /* Triangular Sawtooth Metasurface Antenna */

2021-10-24T15:09:57Z

‎Triangular Sawtooth Metasurface Antenna

A1744012: /* Non-Periodic Square Ring Metasurface Antenna */

2021-10-24T15:07:16Z

‎Non-Periodic Square Ring Metasurface Antenna

A1744012: /* References */

2021-10-24T15:04:33Z

‎References

A1744012: /* Background */

2021-10-24T15:04:29Z

‎Background

← Older revision		Revision as of 15:20, 24 October 2021
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−	~~===3D Radiation Patterns===~~
−	Figure 6 shows the radiation pattern of the simulated design. It can be seen that the antenna is directive in the +Z direction, with a main lobe and a back lobe. The achieved realized gain is approximately 8.6dBi, which would be considerably directive.
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−	Figure 7 shows the radiation pattern of the simulated design. It can be seen that the antenna is directive in the Z direction, however with an equal front lobe and back lobe propagating simultaneously. The achieved realized gain is approximately 4.1dBi, which would not be considered a highly directional antenna. As such, the antenna design is more suited for omnidirectional usage.
−	~~[[File:Radiation pattern 2.png\|thumb\|left\|Figure 6: 3D Radiation Pattern for the triangular sawtooth metasurface antenna]]~~
−	~~[[File:247100212 572287300660256 4280237605968291627 n.png\|thumb\|right\|Figure 7: 3D Radiation Pattern for nonperiodic square ring metasurface antenna]]~~


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		+	===3D Radiation Patterns===
		+	Figure 6 shows the radiation pattern of the simulated design. It can be seen that the antenna is directive in the +Z direction, with a main lobe and a back lobe. The achieved realized gain is approximately 8.6dBi, which would be considerably directive.

		+	Figure 7 shows the radiation pattern of the simulated design. It can be seen that the antenna is directive in the Z direction, however with an equal front lobe and back lobe propagating simultaneously. The achieved realized gain is approximately 4.1dBi, which would not be considered a highly directional antenna. As such, the antenna design is more suited for omnidirectional usage.
		+	[[File:Radiation pattern 2.png\|thumb\|left\|Figure 6: 3D Radiation Pattern for the triangular sawtooth metasurface antenna]]
		+	[[File:247100212 572287300660256 4280237605968291627 n.png\|thumb\|right\|Figure 7: 3D Radiation Pattern for nonperiodic square ring metasurface antenna]]

← Older revision		Revision as of 15:19, 24 October 2021
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	[[File:S-parameters for Triangular Sawtooth Metasurface Antenna.png\|thumb\|left\|Figure 8: Simulated and Measured S-parameters for Triangular Sawtooth Metasurface Antenna]]		[[File:S-parameters for Triangular Sawtooth Metasurface Antenna.png\|thumb\|left\|Figure 8: Simulated and Measured S-parameters for Triangular Sawtooth Metasurface Antenna]]
	[[File:S- parameter Non-Periodic Square Ring.png\|thumb\|right\|Figure 9: Simulated and Measured S-parameters for Non-Periodic Square Ring Metasurface Antenna]]		[[File:S- parameter Non-Periodic Square Ring.png\|thumb\|right\|Figure 9: Simulated and Measured S-parameters for Non-Periodic Square Ring Metasurface Antenna]]
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 [[File:S-parameters for Triangular Sawtooth Metasurface Antenna.png|thumb|left|Figure 8: Simulated and Measured S-parameters for Triangular Sawtooth Metasurface Antenna]]
 [[File:S- parameter Non-Periodic Square Ring.png|thumb|right|Figure 9: Simulated and Measured S-parameters for Non-Periodic Square Ring Metasurface Antenna]]
@@ Line 112: / Line 102: @@
 [[File:Radiation pattern 2.png|thumb|left|Figure 6: 3D Radiation Pattern for the triangular sawtooth metasurface antenna]]
 [[File:247100212 572287300660256 4280237605968291627 n.png|thumb|right|Figure 7: 3D Radiation Pattern for nonperiodic square ring metasurface antenna]]

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 == Results ==
 ===3D Radiation Patterns===
 Figure 6 shows the radiation pattern of the simulated design. It can be seen that the antenna is directive in the +Z direction, with a main lobe and a back lobe. The achieved realized gain is approximately 8.6dBi, which would be considerably directive.
 Figure 7 shows the radiation pattern of the simulated design. It can be seen that the antenna is directive in the Z direction, however with an equal front lobe and back lobe propagating simultaneously. The achieved realized gain is approximately 4.1dBi, which would not be considered a highly directional antenna. As such, the antenna design is more suited for omnidirectional usage.
-[[File:247100212 572287300660256 4280237605968291627 n.png|thumb|Figure 7: 3D Radiation Pattern for nonperiodic square ring metasurface antenna]]
+[[File:Radiation pattern 2.png|thumb|left|Figure 6: 3D Radiation Pattern for the triangular sawtooth metasurface antenna]]
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 [[File:S- parameter Non-Periodic Square Ring.png|thumb|Figure 9: Simulated and Measured S-parameters for Non-Periodic Square Ring Metasurface Antenna]]
 The fabricated antennas S-parameters and radiation patterns are illustrated in (figures). As seen in the S-parameters for the fabricated antenna, the bandwidth is 880 - 980 MHz, therefore the percentage of bandwidth for the measured antenna is 11%.
 == Conclusion ==
+* The triangular sawtooth design achieved a bandwidth of 61% and a stable realized gain of 6.8 dBi. This antenna design exceeds the performance of the reference antenna and the metasurface designs from previous literature.
 == References ==
 [1] C. Balanis, Antenna theory, 4th ed. Hoboken: John Wiley & Sons, 2016, pp. 783-815.

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 One of the metasurface designs consists of triangle-interembedded patch unit cells, produced from horizontal triangular sawtooth radiating slots and straight vertical non-radiating slots. The central horizontal slot is excited at lower frequencies while the sub-central triangular sawtooth slots are excited at higher frequencies. The excitation of these slots produce 2 peaks that merged that greatly increase the bandwidth compared to a standard patch antenna. The antenna consists of 2 substrates, separated by an airgap to improve the gain. The bottom substrate has a ground plane etched on top with an aperture slot, a fork feed is etched on the bottom and the patches are etched onto the top substrate.
 [[File:Final front.png|thumb|left|Figure 2: Top view of the triangular sawtooth metasurface antenna design]]
-[[File:Final back.png|thumb|center|Figure 4: Bottom view of the triangular sawtooth metasurface antenna design]]
+[[File:Final back.png|thumb|center|Figure 3: Bottom view of the triangular sawtooth metasurface antenna design]]
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 The second design utilises non-periodic square-rings as the Metasurface. The design is also composed of two layers, a lower and upper substrate. These layers are spaced using nylon spacers to introduce an airgap. The upper substrate contains the Metasurface structure in place of a typical patch antenna. The lower substrate also incorporates a coupling aperture as the feeding technique. This involves a bottom microstrip fed line, with an aperture slot in the ground plane. This microstrip feed line is adapted to contain a fork-style extension to improve the bandwidth and antenna matching. The final design has a physical size of 0.48λ_0 x 0.48λ_0 x 0.01λ_0 and is a low profile design.
-[[File:Galvin front view.png|thumb|left|Figure 2: Top view of the nonperiodic square rings metasurface antenna design]]
+[[File:Galvin front view.png|thumb|left|Figure 4: Top view of the nonperiodic square rings metasurface antenna design]]
-[[File:Galvin bottom view.png|thumb|center|Figure 4: Bottom view of the nonperiodic square rings metasurface antenna design]]
+[[File:Galvin bottom view.png|thumb|center|Figure 5: Bottom view of the nonperiodic square rings metasurface antenna design]]
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 ==== Triangular Sawtooth Metasurface Antenna ====
-[[File:S-parameters for Triangular Sawtooth Metasurface Antenna.png|thumb|Figure 5: Simulated and Measured S-parameters for Triangular Sawtooth Metasurface Antenna]]
+[[File:S-parameters for Triangular Sawtooth Metasurface Antenna.png|thumb|Figure 8: Simulated and Measured S-parameters for Triangular Sawtooth Metasurface Antenna]]
 The fabricated antennas S-parameters and radiation patterns are illustrated. As seen in the S-parameters for this antenna, the bandwidth is 867 - 1416 MHz, therefore the percentage of bandwidth for the measured antenna is 61%.
 It is noted that the measured antennas bandwidth is slightly larger than the simulated antenna’s bandwidth. The slightly increased bandwidth from the measured antenna was due to discrepancies during the fabrication of the antenna. As the antenna operates at a low frequency, the environment where the antenna is being tested greatly impacts the measurement due to its high wavelength. This can be seen as the simulation S-parameters are a smoother curve than the measured S-parameters.
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 ==== Non-Periodic Square Ring Metasurface Antenna ====
-[[File:S- parameter Non-Periodic Square Ring.png|thumb|Figure 6: Simulated and Measured S-parameters for Non-Periodic Square Ring Metasurface Antenna]]
+[[File:S- parameter Non-Periodic Square Ring.png|thumb|Figure 9: Simulated and Measured S-parameters for Non-Periodic Square Ring Metasurface Antenna]]
 The fabricated antennas S-parameters and radiation patterns are illustrated in (figures). As seen in the S-parameters for the fabricated antenna, the bandwidth is 880 - 980 MHz, therefore the percentage of bandwidth for the measured antenna is 11%.

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 == References ==
-[1] a, b, c, "Simple page", In Proceedings of the Conference of Simpleness, 2010.
+[1] C. Balanis, Antenna theory, 4th ed. Hoboken: John Wiley & Sons, 2016, pp. 783-815.
-[2] ...
+[2] M. Faenzi et al., "Metasurface Antennas: New Models, Applications and Realizations", Scientific Reports, vol. 9, no. 1, pp. 1-2, 2019. Available: 10.1038/s41598-019-46522-z [Accessed 24 May 2021].

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 Since patch antennas are being modified to implement metasurfaces to reduce the antenna size, background about patch antennas and their properties are required. Patch antennas are inexpensive, robust low-profile antennas which have been used in this modern age for many applications, ranging from spacecraft applications to mobile and wireless communication. However, their main drawbacks are their lack of efficiency and power, its narrow bandwidth and their physical size when operating at low frequencies.
-The patch antenna is composed with a patch, dielectric substrate, ground plane and a feed line. The patch of the antenna is a very thin metallic patch which is placed on top of a ground plane but separated by a dielectric substrate that is a small fraction of a wavelength in height
+The patch antenna is composed with a patch, dielectric substrate, ground plane and a feed line. The patch of the antenna is a very thin metallic patch which is placed on top of a ground plane but separated by a dielectric substrate that is a small fraction of a wavelength in height [1]
 [[File:Microstrip Antenna Diagram.png|thumb|Figure 1: Edited excerpt from Antenna Theory: Analysis and Design, Labelled diagram of a typical microstrip antenna design]]
-The patch antenna properties can be altered when replacing the singular patch with a periodic arrangement of metallic patches. This is also known as a metasurface patch, which will alter the space waves emitted from the metasurface patches. The radiated space waves will yield different reflection and transmission properties compared to the singular patch. The gaps between the patches also act as radiating and non-radiating slots, which can excite multiple modes. These multiple excited modes can increase the bandwidth if designed correctly, allowing a higher bandwidth which will help in maintaining performance when miniaturising.
+The patch antenna properties can be altered when replacing the singular patch with a periodic arrangement of metallic patches. This is also known as a metasurface patch, which will alter the space waves emitted from the metasurface patches. The radiated space waves will yield different reflection and transmission properties compared to the singular patch. [2] The gaps between the patches also act as radiating and non-radiating slots, which can excite multiple modes. These multiple excited modes can increase the bandwidth if designed correctly, allowing a higher bandwidth which will help in maintaining performance when miniaturising.
 === Previous Studies ===
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 * Altering the radiating slots
 * Altering the patches
-All the research papers utilise the same feeding style for the antenna, known as aperture coupling. Thus, all the antennas contain 2 substrates separated by a ground plane with the microstrip feed at the bottom. The ground plane contains an aperture slot, allowing the antenna to be non-directly fed. The microstrip feedline changes for some designs as it allows for better impedance matching and increased gain.
+All the research papers utilise the same feeding style for the antenna, known as aperture coupling. Thus, all the antennas contain 2 substrates separated by a ground plane with the microstrip feed at the bottom. The ground plane contains an aperture slot, allowing the antenna to be non-directly fed. The microstrip feedline changes for some designs as it allows for better impedance matching and increased gain. [3]
-The two designs being investigated in this project alter 2 different aspects. One design is inspired from (paper), where radiating slots are altered from horizontal slots to triangular sawtooth slots. The other design draws inspiration from (paper), which alters the patches by implementing square ring patches instead of solid patches.
+The two designs being investigated in this project alter 2 different aspects. One design is inspired from (paper), where radiating slots are altered from horizontal slots to triangular sawtooth slots. [4] The other design draws inspiration from (paper), which alters the patches by implementing square ring patches instead of solid patches. [5]
 == Method ==