Various methods of metering a multi-phase composition in a pipe using patch antenna(s), that operate in a radio or microwave frequency range, are disclosed including locating and then exciting the patch antenna(s) over a range of frequencies; measuring transmitted and reflected signals over time; estimating a shift in a resonant frequency from a baseline resonant frequency; then calculating a permittivity of the composition, based on the shift; and calculating a phase composition of the multi-phase composition. The present invention has been described in terms of specific embodiment(s), and it is recognized that equivalents, alternatives, and modifications, aside from those expressly stated, are possible and within the scope of the appending claims.