Underground Radio Wave Propagation Theory And Scale Experiments

Aiming at the great background and sense about domestic and international study of the underground radio propagation, dissertation, which is based on the Transverse Resonance Theory, not only analyzes the basic theory of the radio propagation which is in the two dimension plane and layered homogeneous medium, but puts forward and designs a method to measure the complex permittivity of soil by analyzing the electricity characteristic and electromagnetic parameter of soil. At the same time, dissertation, taking the theory of Scale Model Method as a base, makes pertinent half-wave antenna. At last, combining the result of the theory and experiment, dissertation verifies the theory of the underground radio propagation.At first, by applying the theory of Transverse Resonance and combining the idiographic test surrounding, dissertation analyzes the law of the underground radio propagation from the theory angle of the underground radio propagation. Then the Simplex Method is used to calculate the perfect propagation constant of the electromagnetic-wave which is in the given frequency and place. Secondly, the measurement about soil's complex permittivity offers a credible source to the simulation software's data. As a part of the integer, dissertation creatively puts forward a measure method about soil's complex permittivity, i.e. the measure method of soil's complex permittivity, which is by using short circuit same axle cavity and is based on the impedance measure. In this method, theory and design including detail are expatiated definitely. Thirdly, dissertation, which starts from the theory of Scale Model Method, concretely designs the form of antenna. At last, basing on the result of theory and experiment, dissertation stresses the pertinent conclusion and analyzes correlative error factors.The result makes it known that the value of measurement about soil's complex permittivity is basically in the range given in the literature, so the method is credible and operational. The analyzing module about the theory of the underground radio propagation, which is based on the Transverse Resonance Theory, has succeeded in making formulating software about the propagation of electromagnetic-wave which is in the two dimension plane and layered homogeneous medium (five layers). According to the validated result of experiment, the theory basically matches the actual measure result, and furthermore, at some frequency, the actual measure result matches the theory quite well (for example, at 900MHz, the curve of attenuation ofthe underground radio propagation), which shows the correctness of theory and the importance of enhancing the means of operation and considering consummated test condition.