Spiral Antenna Design and Implementation

This assignment focuses on the design and implementation of a spiral antenna. Students will delve into aspects such as frequency range determination, balun design for impedance matching, and simulation analysis. A key element is the application of a collaborative approach to project development, emphasizing teamwork and communication throughout the process.

Career Episode 2
Competency Demonstration Report (CDR)

CE 2.1: Project Introduction
Name of the Project : Design of logarithmic spiral antenna
Geographical Location :[Please Fill]
Project Duration : [Please Fill]
Organization : [Please Fill]
Position in the Project : Team Member
CE 2.2: Project Background
CE 2.2.1: Characteristics of the Project
In case of the frequency independent antennas, the polarization, impedance and radiation
pattern are remained unchanged throughout the large domain of bandwidth. I have observed that
the frequency of the antenna remains proportional with the electrical dimension of the antenna.
Therefore, in this project I have worked for developing a los cost and efficient spiral antenna, in
this project I have fed the logarithmic uniplanar antenna and backed the design with coplanar-
waveguide. I have further conducted the simulation of the antenna design for predicting the
performance analysis in respect to the input impedance and radiation pattern for the spiral
antenna.
CE 2.2.2: Objectives developed for project
In this project I have developed the following objective for timely completion of the
project.
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 To provide the antenna specifications for developing the spiral antenna;
 To determine the required configuration for the balun design implemented in the
spiral antenna;
 To conduct the experimental and numerical analysis for the proposed prototype
model for the spiral antenna;
 To simulate the proposed antenna using appropriate simulation software;
CE 2.2.3: My area of work
I have worked in this project for the design specification of the spiral antenna. I have
developed specification and configuration of the balun for transforming the frequency of the
antenna. In addition to that, I have determined the specification and developed the simulation
environment for the performance analysis. In addition to that, I have developed the prototype
model of the antenna and developed the required chamber for the spiral model.
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CE 2.2.4: Project Group
Figure: Team Member Associated with the completion of the Project
CE 2.2.5: My responsibilities throughout the project
I had multifaceted responsibility in this project for the design and implementation of the
spiral antenna. In the initial phase of the project, I have reviewed the past studies and project that
needs to be followed for the development of the spiral antenna. I have further demonstrated the
working principle and theories of spiral antenna to the team members for providing the work
responsibility in the project. Furthermore, I have described the various parameters of the antenna
design and operations for obtaining required frequency and polarization in the spiral antenna. In
addition to that, I took the complete responsibility of communicating with the project lead and
providing regular updates about the deployment of the spiral antenna.
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CE 2.3: Distinctive Activity
CE 2.3.1: Comprehending the Theory of the project
The design of the logarithmic antenna are developed based on two significant equations
namely r1 = r0 eaϴ and r2 = r0 e a(ϴ -ϴ0). In the equations, r2 and r1 are used for demonstrating the
inner and outer radii of the spiral antenna. And r0 eaϴ and r0 e a(ϴ -ϴ0) are the inner and outer initial
radii of the antenna. In the above equations, ϴ is used for considering the angular position of the
antenna. Based on the above equations, I have developed the appropriate design parameter and
demonstrated the width between the arms for obtaining the frequency independent parameter for
antenna design. I have further used 1 to 1.5 turns for obtaining efficient radiation pattern. I have
truncated the spiral arms of the antenna for gaining lower resonant frequency of the physical
antenna. I have ensured that the axial ration of the antenna is decreased with the increased of the
frequencies for obtaining elliptical polarization.
CE 2.3.2: Engineering Knowledge and Skills applied in the project
While working in this project, I have reviewed various past studies on the design and
implementation of the spiral antenna. From the review I have learnt that circular polarization can
be obtained in the spiral antenna design where the frequencies are wither lesser or greater that
wavelength. In this project, I have provides the constant input impedance and varied the
frequency. I have worked in this project for obtaining circular polarization from the circular
antenna considering the one wavelength for electrical arm length. I have used balun for
transforming the CPW (unbalanced coplanar waveguide) for feeding the line along the CPS
(balanced coplanar strip). I have utilized my idea and knowledge about the wideband balun for
transforming the CPW to required CPS. In the design of the balun I have used Chebyshev
impedance four section transformer and ensured 0.05 of reflection coefficient that is denoted by
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Γ. In addition to that, I have utilized slotted radial patch for accomplishing smooth transition.
Moreover, I have attacked two bond wires alongside the plane of discontinuity for ensuring the
equal potential of the grown planes.
CE 2.3.3: Accomplishment and Task Performed
In this project, I have selected 0.52 m length of the arm for obtaining the appropriate 0.58
GHz of resonant frequency. I have set the impedance of the spiral antenna to be 80 ohm. Ii have
used RT/Duroid substrate for developing the balun structure having 0.785 mm thickness, 16 × 43
mm size and 10.2 of dielectric constant. I have further used IE3D as the required simulation
software for performing the analysis of the proposed antenna.
CE 2.3.4: Identified Issues and Their Solutions
Issue: in this project I have selected IE3D for simulating the proposed design for the
spiral antenna. While conducting the analysis, I have observed that effectiveness of the analysis
is significantly reduces with the increased structure of the antenna design. I have faced
significant issue in this project when I was unable to simulate the spiral antenna due t the limited
capacity of the computer and the time allocated for the project. This has created significant
technical and development issue in this project.
Solution: For eliminating the issue, I have broken down the antenna in smaller and
manageable parts. I have used different color for illustrating the different parts in the antenna
design. Through this I was able to simulate each part of the spiral antenna through detailed
design. In this project I have ensured that the increased frequency of the antenna required the
increased size of the antenna. In the initial stage I have conducted the simulation on the antenna
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with providing the frequency between 0.1 to 1.4 GHz. I have further gradually increased the
frequency during the simulation and obtain detailed results as expected.
CE 2.3.5: Plan for producing creative and innovative work
In the spiral antenna, two broad lobes are used that are perpendicular in nature with the
antenna plane. In this project, I have preferred unidirectional pattern of the antenna for detecting
the reflection of the antenna. Therefore, I have created a cavity in the design and used
polystyrene foam with 40 mm and 130 mm of thickness. I have backed the cavity of the results
of the CPW for feeding in the antenna cavity. I have used S-parameters for extending the
bandwidth of the antenna. Furthermore, I have for the applied balun approach I have optimized
the criteria for designing the required spiral antenna criteria. Apart from that, I have design 1.5
GHz and 0.8 GHz of the θ value used in the transmission filed. Through this I was successful in
obtaining appropriate frequencies with the application of the balun design. I have further met all
the required criteria essential for the designing and implementing the appropriate design o the
spiral antenna.
CE 2 .3.6: Collaborative work
I have followed and focused on developing the project with team work and collaborative
approach. I have communicated with the team members for allocating the tasks among us for
easy development and collaboration. I have designed an appropriate resource allocation and
RACI matrix for identifying and easy allocation of the responsibilities, activities and resources
required for completion of the project. In addition to that, I have initiated weekly team meetings
for providing follow up of the developed task and activities.
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CE 2.4: Project Review
CE 2.4.1: Project Overview
I was successful in implementing the spiral antenna with the application of FR-4
substrate. In addition to that, I have used RT/Duroid substrate for the design of the balun
structure. From the analysis, the required and expected results were obtained. The frequency
range of the antenna was observed between 5 GHz to 300 kHz. I addition to that, I have found
the reflection coefficient of the antenna to be higher during the simulation process.
CE 2.4.2: My contribution to work
Before working in this project, I had the practical experience that I have gained from past
projects and workshops. I have used my knowledge and skills in this project for the selection of
the required hardware components and the circuit design for the antenna. I was further associated
in this project for the prototype model development of the spiral antenna proposed. In addition to
that, I have ensured the proper quality and standard of the implementation and design throughout
the antenna design project.
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