Projects:2018s1-196 Concealed Wearable Antennas - Revision history

A1669917 at 04:29, 19 October 2018

2018-10-19T04:29:08Z

A1669917 at 04:27, 19 October 2018

2018-10-19T04:27:45Z

A1669917: /* Fabrication */

2018-10-19T04:26:29Z

‎Fabrication

A1669917: /* Fabrication */

2018-10-19T04:23:44Z

‎Fabrication

A1699158: /* Testing Results */

2018-10-19T04:22:25Z

‎Testing Results

A1699158: /* Testing Results */

2018-10-19T04:20:52Z

‎Testing Results

A1669917 at 04:20, 19 October 2018

2018-10-19T04:20:28Z

A1669917 at 04:19, 19 October 2018

2018-10-19T04:19:11Z

A1669917: /* Simulation Results */

2018-10-19T04:17:41Z

‎Simulation Results

A1669917: /* Simulation Results */

2018-10-19T04:16:18Z

‎Simulation Results

@@ Line 94: / Line 94: @@
 Like with Design A, the antenna was tested firstly using a network analyser to determine the reflection coefficient performance in the frequency domain. Throughout this process, we learned how to properly calibrate the network analyser, and best practices for fastening connectors between cables and equipment. The anechoic chamber was used to test the radiation pattern in the both vertical and horizontal alignments, as well as in co-polar and cross-polarised antenna configurations.
 === Testing Results ===
@@ Line 99: / Line 101: @@
 The results demonstrated a reflection coefficient at 2.4GHz of around -12dB, which was in line with what was expected from simulation. However, the antenna did not exhibit the dual band properties as expected as the next resonant frequency was around 9GHz. It is unclear at this stage what could have caused this discrepancy, but as previously noted, there was difficulty in fabrication that led to a non-ideal construction, which may have influenced the results. The final step in the project is to try to replicate this result in simulation, and make a recommendation as to why the dual band did not perform as expected, whether it was due to construction, and how this could be rectified in future fabrications.
 The radiation pattern data gathered from the anechoic chamber is still under analysis, but a preliminary view demonstrates a largely omnidirectional radiation pattern as expected.

@@ Line 71: / Line 71: @@
 The design is based around a dielectrically loaded monopole antenna. The dielectric core forms the stem and top portion of the button, with a central pin that enters through the bottom of the dielectric stem, and terminates to a metallic disc at the top. This top disc allows for the antenna to achieve resonance at a relatively low frequency (2.4GHZ) while minimising the vertical height. The ground plane continues up the stem of the antenna, providing a grounding shield. This reinforces the structure, and allows for capacitive coupling with the interior probe, a characteristic which is critical in achieving the dual band performance. The antenna is fed by a coaxial connector below the ground plane, and the entire antenna assembly was modelled as mounted atop a sheet of velcro.
-[[File:modelB.png|center|500px|thumb[Simulation Model of Design B]]
+[[File:modelB.png|center|500px|thumb|Simulation Model of Design B]]
 === Simulation Results ===
 The results achieved through this design displayed optimisation in the second band rather than the first, achieving a reflection coefficient of around -12.4dB at 2.45GHz, and -16.2dB at 5.8GHz. The simulated radiation pattern, as desired, was largely omnidirectional. As expected from a monopole antenna, the low-band resonant frequency was largely determined by the height of the antenna, and radius of the top disc. The high-band resonant frequency was controlled by the height of the ground casing of the stem, as well as the radius of the stem. The impedance transition was carefully altered in an effort to match the performance at both bands.
-[[File:DesignBReflectionCoefficient.jpg|center|500px|thumb[Graph of Reflection Coefficient for Design B]
+[[File:DesignBReflectionCoefficient.jpg|center|500px|thumb|Graph of Reflection Coefficient for Design B]]
-[[File:DesignBRadiationPattern2.4.jpg|center|500px|thumb[Radiation Pattern of Design B at 2.4GHz]]
+[[File:DesignBRadiationPattern2.4.jpg|center|500px|thumb|Radiation Pattern of Design B at 2.4GHz]]
 === Fabrication ===
@@ Line 88: / Line 88: @@
 While this did simplify the design and allow for more feasible fabrication, it was discovered that, due to the setting of the 3D printed material, some dimensions for the antenna were not realised as the same that were modelled. This proved difficult as, after many attempts, unfortunately we were not able to produce another model of the dielectric core due to difficulties with the 3D printer. Due to time constraints, fabrication needed to proceed using a dielectric core that was not to the ideal specifications.
-[[File:frontView.jpg]]
+[[File:frontView.jpg|center|500px|thumb|Fabricated Design B]]
 === Testing ===

← Older revision		Revision as of 04:26, 19 October 2018
Line 89:		Line 89:

	[[File:frontView.jpg]]		[[File:frontView.jpg]]
−
−	~~[[File:topView.jpg]]~~

	=== Testing ===		=== Testing ===

← Older revision		Revision as of 04:23, 19 October 2018
Line 87:		Line 87:

	While this did simplify the design and allow for more feasible fabrication, it was discovered that, due to the setting of the 3D printed material, some dimensions for the antenna were not realised as the same that were modelled. This proved difficult as, after many attempts, unfortunately we were not able to produce another model of the dielectric core due to difficulties with the 3D printer. Due to time constraints, fabrication needed to proceed using a dielectric core that was not to the ideal specifications.		While this did simplify the design and allow for more feasible fabrication, it was discovered that, due to the setting of the 3D printed material, some dimensions for the antenna were not realised as the same that were modelled. This proved difficult as, after many attempts, unfortunately we were not able to produce another model of the dielectric core due to difficulties with the 3D printer. Due to time constraints, fabrication needed to proceed using a dielectric core that was not to the ideal specifications.
		+
		+	[[File:frontView.jpg]]
		+
		+	[[File:topView.jpg]]

	=== Testing ===		=== Testing ===

@@ Line 62: / Line 62: @@
 === Testing Results ===
-After testing the antenna, the results were recorded and plotted in excel. The S-parameter result shows the same curve as the simulation graph. There is only slightly difference for the matching frequency as it is reflected at 2.43 GHz and 5.63 GHz. The reflection coefficient increase a little bit compared to the simulation result but it still shows good matching with -15.9 dB at 2.43 GHz and -13.8 dB at 5.63 GHz. The radiation pattern also showsa good omni-directional pattern at both frequencies.
+After testing the antenna, the results were recorded and plotted in excel. The S-parameter result shows the same curve as the simulation graph. There is only slightly difference for the matching frequency as it is reflected at 2.43 GHz and 5.63 GHz. The reflection coefficient increase a little bit compared to the simulation result but it still shows good matching with -15.9 dB at 2.43 GHz and -13.8 dB at 5.63 GHz. The radiation pattern also shows a good omni-directional pattern at both frequencies.
 [[File:S-parameter plot.png|center|500px|thumb|Fig 10. Measured Return Loss]]

← Older revision		Revision as of 04:20, 19 October 2018
Line 61:		Line 61:

	=== Testing Results ===		=== Testing Results ===
		+
		+	After testing the antenna, the results were recorded and plotted in excel. The S-parameter result shows the same curve as the simulation graph. There is only slightly difference for the matching frequency as it is reflected at 2.43 GHz and 5.63 GHz. The reflection coefficient increase a little bit compared to the simulation result but it still shows good matching with -15.9 dB at 2.43 GHz and -13.8 dB at 5.63 GHz. The radiation pattern also showsa good omni-directional pattern at both frequencies.
		+
		+	[[File:S-parameter plot.png\|center\|500px\|thumb\|Fig 10. Measured Return Loss]]

	== Design B: Christian Colombo ==		== Design B: Christian Colombo ==

← Older revision		Revision as of 04:17, 19 October 2018
Line 73:		Line 73:

	[[File:DesignBReflectionCoefficient.jpg]]		[[File:DesignBReflectionCoefficient.jpg]]
		+
		+	[[File:DesignBRadiationPattern2.4.jpg]]

	=== Fabrication ===		=== Fabrication ===