Low Footprint Meander Monopole Patch As EMI Sensors

Low footprint monopole patch is proposed for sensing application in the Very High Frequency (VHF) band. Meander based monopole is considered, to realize small size, thus reducing the substrate dimensions. A mathematical model is attempted, to develop a generalized design equation, at any frequency. Coaxial fed and microstrip line fed feeding systems are simulated. The design frequency is 100MHz, and simulation results employing HFSS exhibit return loss less than -20 dB at 110MHz. The gain needs considerable improvement. The footprints observed are 140 cm$^{2}$ and 1200 cm$^{2}$, for coaxial fed and microstrip line fed models respectively. Larger footprint of the microstrip line fed structure is attributed to the quarter wave transformer required for impedance matching. Antenna factor characterization is presented in the frequency range 50MHz – 150MHz for the microstrip line fed patch. Prototype fabrication and experimental validation could provide the next insights required for improving antenna parameters including gain. VHF based sensing is gaining attention as the preferred band in various domains including agriculture, drone charging. Low footprint VHF antennas provide scope for vehicle mounting, for conducting measurements for evaluating CISPR 12/CISPR 25 standards.