Miniature Dipole Antenna for Active Near-Field Sensor

In EMC analysis, electromagnetic near-field scanning of printed circuit boards as well as of large scale integrated circuits becomes more and more popular. One approach to measure electromagnetic field distributions with high spatial resolution and sensitivity is the use of miniature active field probes. A small dipole probe on GaAs substrate intended to be integrated with active circuitry is reported in this work. Our target frequency range is from 1 MHz to 3 GHz and is planned to extend up to 10 GHz. The electrical properties of the sensor are investigated by simulations with two software packages and a lumped equivalent circuit is presented. The effect of the GaAs substrate, the load impedance and the trace width of the dipole structure on the sensitivity of the probe is discussed.