Prediction of millimeter(mm)-wave radio signals can be beneficial in recreating and repeating atmospheric conditions in a
controlled, laboratory environment. A path-loss model has been proposed that accounts for free-space losses, oxygen absorption,
reflection and diffraction losses, and rain-rate attenuation at mm-wave frequencies. Two variable passive
low-pass-integrated circuit filter structures for attenuation in the 57–64 GHz unlicensed frequency band have been proposed,
designed, simulated, prototyped in a 130-nm SiGe bipolar complementary metal-oxide semiconductor process, and measured.
The filters are based on the Butterworth and Chebyshev low-pass filter topologies and investigate the possibility of using the
structures to perform amplitude attenuation of mm-wave frequencies over a short distance. Both filters are designed and
matched for direct coupling with equivalent circuit models of dipole antennas operating in this frequency band. Full integration
therefore allows prediction of atmospheric losses on an analog, real-time, basis without the requirement of downconverting
(sampling) to analyze high-frequency signals through a digital architecture. On-wafer probe measurements
were performed to limit parasitic interference from bonding wires and enclosed packaging.