Design and Validation of an Adaptive Cubesat Transmitter System Using a Thermal Vacuum Chamber (TVAC)
F. D. Jaswar1, T. A. Rahman2, Y.A. Ahmad3

1Fitri Dewi Jaswar, Universiti Teknologi Malaysia, Skudai, Johor, Malaysia.
2Tharek Abd. Rahman, WCC, Universiti Teknologi Malaysia, Skudai, Johor, Malaysia.
3Yasser Asrul Ahmad, Kulliyah of Engineering, IIUM, Gombak, Selangor, Malaysia.
Manuscript received on 18 November 2019 | Revised Manuscript received on 04 December 2019 | Manuscript Published on 10 December 2019 | PP: 207-212 | Volume-8 Issue-3S2 October 2019 | Retrieval Number: C10391083S219/2019©BEIESP | DOI: 10.35940/ijrte.C1039.1083S219
Open Access | Editorial and Publishing Policies | Cite | Mendeley | Indexing and Abstracting
© The Authors. Blue Eyes Intelligence Engineering and Sciences Publication (BEIESP). This is an open access article under the CC-BY-NC-ND license (

Abstract: CubeSat in a low earth orbit primarily uses a UHF transmitter with a fixed RF output power. In this paper, the design of the CubeSat transmitter with adaptive power control ability is presented. The design drive is to optimise the SNR and overcome the variability of the propagation path length due to different ground station elevation angles by adjusting its transmitting power. The TVAC test is conducted to validate the performance of the adaptive function in the transmitter. The TVAC is used to emulate the satellite condition in an outer space environment. Four thermal cycles starting from +60°C to -20°C with less than 10-5Pa pressure condition are employed, which was conducted at the KIT CeNT, Japan. The transmitter was integrated inside the satellite structure as a complete CubeSat system. The output power of the transmitter is tested from 0.5W to 2W based on the proposed satellite adaptive mode. The frequency stability of the transmitter is monitored and complies with an average of 70% below requirement, which is less than 2ppm. The results indicate that the RF output power is adjustable to operate as the proposed CubeSat adaptive transmitter in a thermal vacuum condition, which was first developed in Malaysia.
Keywords: Adaptive System, Low Earth Orbit Satellites, UHF Communication, Cubesat, Transmitter.
Scope of the Article: Adaptive Systems