Intercomparison of Methods for Determination of Resonant Frequency Shift of a Microstrip Patch Antenna Loaded with Hevea Rubber Latex

Table 2

Relationship between resonant frequency shift, 𝑓_shift and moisture content.

Method	Regression equation	Regression coefficient, 𝑅^2	Sensitivity,; (GHz/% 𝑚.𝑐.)
Measurement	𝑓shift=6.62×10^6𝑚.𝑐.+1.59×10^8	0.7985	0.007
FEM	𝑓shift=1.97×10^6𝑚.𝑐.+4.26×10^8	0.4766	0.002
MoM	𝑓shift=1.64×10^7𝑚.𝑐.+3.77×10^8	0.9368	0.02
Variational A	𝑓shift=9.43×10^6𝑚.𝑐.−1.81×10^8	0.9999	0.009
Variational B	𝑓shift=7.13×10^6𝑚.𝑐.+8.60×10^7	0.9549	0.007