Configurable Resonant and Broadband Magnetic Near-Field Probe

A magnetic field probe is described which can be configured to be either broadband or resonant. The designs shown range in size from 4 x 4 mm to 0.8 x 0.5 mm loop size and can be configured to be resonant from 600 MHz to 2700 MHz. The design is based on a 4-layer PCB. When configured as a resonant probe, the sensitivity is approximately 12 dB better than a wideband configuration of the same size. The unwanted E-field rejection is also 18.5 dB. The effect of design choices on the Q-factor is discussed.