Design and Integration of Communication subsystem for Pratham

Department of Aerospace EngineeringIIT Bombay

ContentsDesign of telemetry, beacon and uplink

modules

Design and fabrication of final Onboard PCBs

Allocation of frequencies by IARU

Integration of Groundstation at IITB

Social Goal  

Communication Subsystem Onboard

Beacon

Telemetry

Uplink

Groundstation

PolarisationMeasurement

Signal reception

Telemetry Module

• CC 1020 daughter board

• Coded by OBC• Data input in the

form of AX.25 packets

Modulates the signal

• RF5110 G with perpendicular berg strips and perpendicular SMA

Amplifies the signal • Monopole

• Characterization done

Radiates the signal

Beacon Module

• Atmega 8 microcontroller to be used

• Bit banged code to be used as 8 bit SPI not working

Codes the daughter

board

• ADF 7020 daughter board

• Transmitting at 144.5 MHz

• To be tuned • Duty cycle is 25 %

Modulates the signal

• RF5110 G with perpendicular berg strips and perpendicular SMA

Amplifies the signal

• Monopole• Characterization

done

Radiates the signal

Uplink Module

• Monopole• Characterizati

on done

Radiates the signal

• SRZ LNA from RFMD

• To be characterised

• Satisfies the operational parameters

Amplifies the received signal • CC 1020

daughter board• Receiving at 437

MHz• Demodulates

after a certain RSSI value

Demodulates the signal

• Atmega 8 microcontroller to be used

• Decode the kill signal and pass on to Power

Decodes the signal

Monopole and Monopole holder

Onboard antenna mounting

Allocation of frequencies by IARUConditions for frequency allocation

Amateur Ham License or a Custodian Detailed link budget analysis Telemetry sequenceDetails about the GS and Onboard circuity and

their functionalitiesUplink or telecommand to control the satellite.

Groundstation setup: Polarisation

• Crossed Yagi mounted on a rotor controlled by NOVA and ARS

Antenna

Groundstation setup: Telemetry

• Crossed Yagi mounted on a rotor controlled with ARS and NOVA

Antennae

Social Goal We have undertaken Social goal as a part of

our Communication Subsystem task. The Social goal aims to involve universities

across the nation for the purpose of generating a TEC Map of India.

The readings received from the Groundstation can also be used for the purpose of Tomography of the Ionosphere.

We have also entered into a collaboration with IPGP France who shall be utilising our TEC data for their scientific research.

Thank You