Design and Analysis of Helical Antenna for GPS Systems

The primary objective of designing a helical antenna tailored for GPS-based systems. The antenna is tuned to the GPS frequency (3010MHz) and exhibits optimized parameters critical for better performance. The helix dimensions, including pitch angle (0.2 times the wavelength) and diameter($3.17 \mathrm{~cm})$, are carefully chosen to influence the radiation pattern (circularly polarized omnidirectional), while the number of turns (7) and spacing ($9.47 \mathrm{e}-3$) are adjusted to balance impedance and axial ratio. The antenna achieves a low axial ratio (close to 1), ensuring the return loss is greater than $20 \mathrm{~dB}$ between 2.3GHz to 2.4GHz with a strategically calculated gain of $9.03 \mathrm{~dB}$ at the center frequency and sufficient bandwidth covering the GPS frequency band with VSWR close to 1, the antenna promises reliable signal reception. Impedance matching occurs from 2.4GHz. The helical antenna aligns with right-hand circular polarization, essential for GPS signals. The resulting radiation pattern exhibits a well-shaped coverage, characterized by high gain in the zenith direction and controlled gain in opposing directions. This design signifies a robust solution for GPS-based navigation, offering optimal performance across a range of key parameters.