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RF frequency conversion is a key function of telecom satellite payloads. Hereafter are presented new photonic RF sub-system concepts supporting multi-channel, wideband frequency-conversion, thus drastically reducing the amount of equipment, for frequency down- and up-conversions respectively at the inputs and outputs of a digital processor. Proof-of-concept demos are presented and the measured RF performance reviewed vs. predictions and system requirements. The so-called dual-band, multi-LO frequency-converter (DB-MLFC) concept is an extension of the multi-LO frequency-conversion scheme already proven by Thales Alenia Space. It makes use of a dual-drive modulator with wavelength-multiplexed LO input and RF signal inputs in separate frequency bands. It can be applied to digital processor-based payloads and perform down-conversion of Ka or V-band sub-bands to the C-band of the processor input. The DB-MLFC concept was proven to support down-conversion of 2 and 3 sub-bands from the Ka (~30 GHz) and V (~50 GHz) bands to the C (~6 GHz) band of the processor input. The second concept called multi-RF frequency-converter (MRFC) consists in mixing multiple RF signals on separate optical carriers with an electrical LO signal into one electro-optical mixer. RF signals to undergo the same frequency conversion are combined via a WDM and fed into the optical input port of an electro-optical modulator, the RF port being driven by the LO. The RF performance of the MRFC concept, were measured with up-conversion of up to 8 C-band RF signals from the processor output to Ka-band payload output frequencies (~20 GHz).
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