This thesis describes a method for designing an RF system for measuring rain-induced attenuation and depolarization at millimeter wavelengths. Path length, dynamic range, and polarization isolation are discussed with respect to their importance to RF system performance. Design considerations for the VPI&SU 17.65GHz,CW, RF system are presented. The path length is 1.43km, the receiver dynamic range is 71dB, and the orthogonal polarization isolation is greater than 60dB for the receiver and transmitter. The paper concludes with sample data taken with the VPI&SU system during several rain storms in 1972. / Master of Science