A 61-GHz RFID frontend with SiGe transceiver MMIC and SIW coupling network

This paper presents the frontend of a 61-GHz RFID reader. The frontend consists of a transceiver MMIC, an open waveguide used as a circular polarized antenna and a coupling network. The coupling network connects the MMIC with the open waveguide antenna and provides isolation between the receive and transmit path. It is realized in substrate integrated waveguide technology. The MMIC was fabricated in a 130-nm SiGe BiCMOS technology and includes a voltage controlled oscillator, a receive mixer and a power amplifier. The power amplifier uses Wilkinson-combiners to implement the concept of power combining and achieves an output power of 19dBm at 61GHz. The equivalent isotropically radiated power was measured to be 23.48dBm, which is to the authors' best knowledge the highest value reported for 61-GHz RFID readers.