Si-based 60GHz 2X Subharmonic Mixer for Multi-Gigabit Wireless Personal Area Network Application

This paper presents the design and development of a 60GHz 2times passive subharmonic mixer in a silicon-germanium (SiGe) process. Wide bandwidth operation of the mixer is indispensable for the integration of a low power wireless front-end at 59-64GHz license-free frequency band for the direct up and down conversion of multi-gigabit digital data. An anti-parallel diode pair (APDP) has been incorporated to generate the non-linearity and the ground shielded coplanar transmission lines as well as a coupled microstrip section realizes the necessary impedance matching conditions. The mixer has a measured minimum down-conversion loss of 8.3dB with a greater than 4GHz of single-sided 3-dB baseband bandwidth with a 5.5dBm local oscillator signal at 30.5GHz. An input 1dB compression point of -7dBm has been recorded. This is the first report of a 60GHz subharmonic mixer in SiGe processes that can be applicable to multi-gigabit wireless personal area network application