SMALL E AND H FIELD ANTENNAS AND PROBES
These small antennas and probes are designed to measure the susceptibility of PCBs, ICs or small equipment to high levels of E and H fields. One use was measuring the susceptibility of the memory in an aircraft black box. The IC was powered by an external battery or battery and linear regulator external to the antenna containing the IC. The fields described here were achieved using a R&K A009K251-4949R 9kHz – 250MHz 75W power amplifier.
A step up/ step down transformer useful from 0.01MHz to 10MHz is available from EMC consulting and the calibration of this is supplied under Calibrations:
Using the step down feature with any of the H field antennas/probes a higher level of current and magnetic field is achieved.
Custom antennas can be manufactured with different dimensions and frequency range than those described here to suit the EUT or PCB size.
This antenna can theoretically develop 7600V/m but practically the limit is 1500V/m due to voltage breakdown. The upper frequency limit is very high due to the small gap between the ground plane and the upper plate and it has been tested from dc 250MHz. The dimensions may be increased to suit any PCB size.
Price: $1000US | $1300CAN, with calibration
The 10cm stripline can develop 614V/m from 0.3MHz to 30MHz when used with the step up transformer and the frequency range is dc – 300MHz. The calibration for this antenna is shown under Calibrations.
The stripline at 7.5cm, 10.5cm, 12.7cm and 18cm height
They can generate a minimum of 50V/m with a 20W input level. Calibration is shown under Calibrations. This antenna can accommodate EUTs with the following dimensions and the upper frequency limits are:
This antenna can generate very high currents and therefore fields at the resonant frequency. It has been tested with a step down transformer to more closely match the impedance of the power amplifier. The antenna shown in the photo has been tuned to resonate at 13.65MHz and this can be changed by modifying the value of the capacitors. The probe can be ordered with a resonance of between 3.6MHz to 35MHz. The gap between the winding is 6mm, the length is 6.8cm and the width 11.5cm. The maximum H field is approximately 250A/m. The calibration is shown under Calibrations.
Price: $1000US | $1300CAN, with calibration
The ratio as a step up transformer when loaded with 450 Ohm is from 2.7 to 3 and for a step down transformer when loaded with 5.6 Ohm ranges from 0.4 to 0.1. The calibration is shown under Calibrations.
Price: $150US | $190CAN
