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Development of Deployable Antennas for the Diwata-2 Microsatellite’s…
Development of Deployable Antennas for the
Diwata-2 Microsatellite’s Amateur Radio Payload
Antenna Design Considerations
Monopole antennas
provide omnidirectional radiation pattern
reduce physical dimension
specification
type: quarter wave monopole
polarization: linear
placement of antenna
considerations
Coupling between URX (UHF TX and UHF RX for D2 command uplink) and UHF
Radiation pattern
Shadowing on the solar panels
stowed within the structure, deployed once in orbit
ARU antennas
consist of copper rods mounted on a spring-loaded hinge assembly
initial rod lengths are 17 cm and 50 cm for UHF and VHF bands
retention and deployment
failure
retention
will cause premature deployment of the antennas
will cause the satellite to be stuck inside its deployer
deployment
will result with the malfunction of the ARU payload
the antennas remained stowed while already in orbit
design used was decided based on the structural constraints of Diwata-2
Dyneema® wire is used to hold the antenna to its stowed position
wire passes through resistors that serve as the
heating element for cutting the wire
resistors are mounted on a deployment board that also contains a feedback switch and a modified hook that provides tension to the wire
To ensure reliability, two deployment boards, with two Dyneema® wires per board, are allocated for each antenna
torsion spring
provides the energy for the deployment of the antenna
deployment
deployment of the antenna was constrained to 90 degrees to avoid obstruction with field of view of the other payloads of Diwata-2
deployment is detected through the change in state of the feedback switch mounted on the deployment board
The switch is pressed to an initial position using the antenna rods in stowed position
Conclusion
retention and deployment system
could function under the specified launch and space environment conditions
antenna pattern
design suitable for use of Diwata-2’s amateur radio payload
selected placement
ensures minimum shadowing in the solar arrays and optical payloads
exhibit minimal coupling with the Diwata-2’s command uplink receiver antenna
omnidirectionality
provide satisfactory results on directions where the optical payloads are facing the Earth