Design and simulation result of various spiral antennas. Spiral antennas belong to the class of "frequency independent" antennas; these antennas are characterized as having a very large bandwidth. Spiral antennas are travelling wave structures and are well-known for their wideband performance. A bandwidth of 5:1 or 10:1 is easily obtained and a stable input impedance is achieved through a self-complementary geometry. This wideband characteristic of the spiral antenna makes it an attractive choice where a single antenna is required to send / receive over multiple channels. Spiral antennas are usually circularly polarized. The spiral antenna's radiation pattern typically has a peak radiation direction perpendicular to the plane of the spiral (broadside radiation). The Half-Power Beamwidth (HPBW) is approximately 70-90 degrees. Spiral antennas are widely used in the defense industry for sensing applications, where very wideband antennas that do not take up much space are needed. Spiral antenna arrays are used in military aircraft in the 1-18 GHz range. Other applications of spiral antennas include GPS, where it is advantageous to have RHCP (right hand circularly polarized) antennas. There are several kind of spiral antennas . An Archimedean spiral made of two equal lengths of coaxial cable seems to be the easiest circularly polarized antenna to make that'll cover a broad range.

1. Spiral Antennas
Sr. No. Design Name Solver
1 Coaxial Fed Single arm Spiral Antenna FEM
2 Rectangular Spiral Antenna FEM
3 Vivaldi Spiral Antenna FEM
4 Two arm Circular Spiral Antenna FDTD
Anil Pandey

2. Coaxial Fed Single arm Spiral Antenna
Solver – FEM (Direct)
1

3. S-Parameters Data
Operating Frequency : 10 GHz
1

4. Far-Field Plot
Gain - 6.5 dBi
1

5. Rectangular Spiral Antenna
Solver - FEM
2

6. 2S-Parameters Data

7. Far Field Plot
Gain – 1.2 dBi
2

8. Vivaldi Spiral Antenna
Solver – FEM (Direct
3

9. S-Parameter 3

10. Gain - 2.9 dBi
Resonance Frequency 2.93 GHz
3
Far Field Plot

11. Two arm Circular Spiral Antenna
Solver – FDTD
Conformal Meshing
CUDA Card
4

12. FDTD Simulation Data
Frequency : 1.6 GHz
4