Multicarrier transmission gain and group delay measurements

Abstract

This thesis documents the Multi-Carrier Group Delay and gain measurements for OneWeb satellites with frequency translation in satellite communication. The uplink is in the Ka-band and the downlink is in the Ku-band. The transmission gain and absolute group delay measurements are implemented although the local oscillator (LO) is not accessible. These measurements are implemented by using the OneWeb Payload Test System for Radio Frequency Special Check-Out Equipment Electrical Ground Support Equipment (PTS RF SCOE EGSE). The PTS RF SCOE consists of distinct measurement units for various measurement goals. The OneWeb RF SCOE consists of a signal generator, spectrum analyzer, switch control unit, RF matching unit, RF FrontEnd and a host server to link these components together. For more information about RF SCOE please refer to https://atos.net/en/products/aerospace-defense-electronics/egse. The focus of this document is on multi-carrier gain and group delay measurement of the OneWeb satellite which henceforth will be called the Device Under Test (DUT). The two main measurement units that are utilized to perform the measurements for transmission gain and group delay are two signal generators and a spectrum analyzer. Having information about the phase and magnitude response of the DUT is sufficient to measure the gain and group delay of the DUT. The Rohde and Schwarz FSW 43 spectrum analyzer includes an I/Q-Analyzer. The magnitude and phase of the input RF signal are measured by reading I/Q-data from the spectrum analyzer. Consequently, the measured magnitude and phase are calculated to measure the group delay and gain of DUT with frequency translation. This thesis provides information on how to obtain the necessary parameters from Analog Spectrum Analyzer (ASA) for measuring the transmission gain and absolute group delay. Measuring the gain and group delay need two specific calibrations prior to the multi-carrier transmission gain and absolute group delay measurement. The TAC and multi-carrier calibrations give us the reference gain and phase response versus frequency curves for Multi-Carrier Measurements (MCMs). All specific calculations are performed for accurately estimating the absolute group delay and transmission gain of the DUT. Three possible fast internal calibrations are suggested as a replacement of the repetitive and time-consuming TAC and multi- carrier calibrations. Finally, measuring the transmission gain of the same DUT with different interfaces of the RF front end ends up to constant transmission gain of the DUT.

This thesis documents the Multi-Carrier Group Delay and gain measurements for OneWeb satellites with frequency translation in satellite communication. The uplink is in the Ka-band and the downlink is in the Ku-band. The transmission gain and absolute group delay measurements are implemented although the local oscillator (LO) is not accessible. These measurements are implemented by using the OneWeb Payload Test System for Radio Frequency Special Check-Out Equipment Electrical Ground Support Equipment (PTS RF SCOE EGSE). The PTS RF SCOE consists of distinct measurement units for various measurement goals. The OneWeb RF SCOE consists of a signal generator, spectrum analyzer, switch control unit, RF matching unit, RF FrontEnd and a host server to link these components together. For more information about RF SCOE please refer to https://atos.net/en/products/aerospace-defense-electronics/egse.