Optimized straight CTL cell to calibrate EM field probes in air up to 2.1 GHz

The author describes an optimized straight CTL cell whose uniform area is 2cm times 2cm and field uniformity is plusmn1 dB to calibrate small EM field probes in air. We could obtain the cell with the broadband frequency range up to 2.1 GHz. The field uniformity and frequency range of the cell are compared with those of square type CTL cell and symmetric TEM cell with same test zone in this paper. It is shown that the optimized CTL cell can provide the standard EM fields with broadband frequency range. The measured electric fields and resonant frequencies of the designed CTL cell agree well with the simulated results by moment methods (MM) and variational method (VM) respectively