E-Band Transmitter with 3 W Complex Modulated Signal Output Power Performance

This paper reports on an E-band transmitter frontend designed to operate on a CubeSat platform to explore high data rate downlink from a low earth orbit. The LO generation, the up-conversion and the RF pre-amplification realized by MMICs based on 50 nm InGaAs metamorphic high electron mobility transistor technology. The final amplification stage comprises two solid-state power amplifier chips, parallelized with waveguide techniques into a single split-block waveguide module, utilizing an AlGaN/GaN-HEMT technology with 100nm gate length. The Tx chain is characterized, both, with single IF tones and wideband complex modulated signals. The transmit frontend achieves a record maximum output power of 3 W for a QPSK modulation with 7.4 Gbit/s data rate, demodulated with a broadband receiver. A maximum QPSK-modulated symbol rate of 6 Gbd could be captured by the signal analyzer software with an EVM of 34% and signal power of 33dBm. In addition higher order modulation formats 16- and 32-QAM are demonstrated.