Design Of CPW Electromagnetic Probe Antenna

With the fast developing science, gradually spreading of the electric automation, the popularization of electric products have already embedded into all aspects of our daily life. Because of this, electromagnetic radiation pollution has already been a kind of new pollution in our daily life which has already aroused extensive attention. People begin to keep a watchful eye on it and concern about whether a long time explosion in this kind of environment can cause negative effects to our healthy. Aimed at the radiation pollution, related organizations and competent technicians in the world have already set up many different kinds of standards and criterions to avoid the negative effects to organism.First important thing to measure and then avoid the harm of the electromagnetic radiation is to detect it. And now the main method to detect the electromagnetic radiation is to use the electromagnetic probe. This article aims to design the antennas of the electromagnetic probe with good performance. The author knows the requirements about the operating theory and the probe antennas'performance through an extensive reading of relative data, and then summarized the research theories and the design methods. Based on this, the author made improvements on the antennas of the electromagnetic probe step by step. The transition line is used to reduce the impacts brought by the discontinuity and shorted wire is used to restrain the resonance, and then new structures of a dipole antenna feed by coplanar waveguide used for detection of the electric field and a ring form antenna for the detection of the magnetic field are proposed.In this article, the equivalent circuit theory is used to analyze the basic theory of the electromagnetic probe antennas, and HFSS is used to simulate and optimize the different structures of the probe antennas proposed in this article. Finally we provide the size of the probe antennas and according to these sizes the probe antenna is fabricated and tested. The results show that at the required frequency range 0Hz--9GHz, the S11-parameter of the probe antenna appears to be flat enough. The united simulation which includes the probe antenna and the microstrip line as the device under test (DUT) is proceeded, and the coupling signal of the output result is in the range o -20dB to-60dB which can make sure the measured results'accuracy. All of the results above show that the antennas in this article with different structures are all have the performance which can satisfy the requirement of the design.