Investigation of Cavity Resonances in an Automobile

Knowledge of cavity resonance within the automobile is needed to predict electromagnetic crosstalk between circuits in vehicle cavities. To quantify potential cavity resonances, resonance was studied within the passenger compartment of a standard automobile. Measured values of S11, S21 and Q (quality factor) are presented and their effect on crosstalk is discussed. Resonances were found at frequencies from 72 MHz to 303 MHz with quality factors ranging from 4 to 40