A PCB-Based Wideband H-Probe for Near-Field Scanning

An ultra-wideband H-probe is presented for near-field measurement. It can be used to measure the magnetic near-field strength. The probe is constructed based on a microstrip line with a modified strip loop at the end. An H-probe with dimension of 8.1 mm × 8 mm is fabricated in a 0.508 mm thick RO4003C substrate. The probe operates over 2 GHz to 18 GHz frequency range with the coupling level varying within −28± 4 dB. The measured calibration results agree well with that predicated from full wave simulations.