Compact UHF Circularly Polarized Multi-Band Quadrifilar Antenna for CubeSat

Area of Science:

• Aerospace Engineering
• Electrical Engineering
• Radio Frequency (RF) Engineering

Background:

• CubeSats require compact, reliable antennas for communication.
• Existing antennas may lack multi-band capabilities or robustness for launch vibrations.

Purpose of the Study:

• To design and validate a multi-band, right-hand circularly polarized antenna for CubeSat applications.
• To enhance antenna durability against launch-induced vibrations.

Main Methods:

• A quadrifilar antenna structure was designed and fabricated using FR4-Epoxy boards.
• A ceramic spacer and screws were incorporated for structural integrity.
• Antenna performance was measured in an anechoic chamber and validated via a real-world space-to-ground link.

Main Results:

• The antenna covers LoRa frequency bands (868, 915, 923 MHz) with dimensions of 77 × 77 × 10 mm³.
• Measured gains of 2.3 dBic at 870 MHz and 1.1 dBic at 920 MHz were achieved.
• Successful integration and communication link confirmation on a 3U CubeSat launched in September 2020.

Conclusions:

• The designed antenna meets the requirements for CubeSat communication, offering multi-band operation and enhanced robustness.
• The antenna's performance was validated through anechoic chamber measurements and a successful space mission.
• This design provides a reliable solution for CubeSat terrestrial-to-space communication links.