Broadband electromagnetic field strength sensors for 40-300 GHz based on planar log per antennas and high-speed Schottky diodes

Due to the wide-spread use of broadcasting devices for mobile applications, surrounding levels of radio frequency (RF) radiation, particularly in cities and work places, tend to increase in the EU. A project funded by the EU aims to address the health and exposure requirements for the electromagnetic fields that are in wide-spread public use. This includes the development of traceable electromagnetic field (EMF) sensors for a wide range of frequencies. While field probes operating up to 40 GHz are commercially available, there are only few sensors and no artifact standards for power flux density available above 40 GHz. To compensate this lack, we present EMF sensors based on Schottky diode detectors and planar logarithmic periodic antennas etched on the microwave substrate RO3003. The new sensors were designed and optimized using the electromagnetic simulations software CST Microwave Studio based on the finite differences time-domain method. Simulations and measurements show a reliable frequency response of the detector within the frequency range between 40 GHz and 300 GHz. As a radiation source for characterization, a setup composed of vector network analyzer and a series of frequency converters is implemented.