A Research Of Microwave And Millimeter Wave Electrical Properties Of Biological Tissue

Cancer as known as high incidence rate disease which is threatening to human beings’ health, people are fighting against cancer during the last hundred years. The prediction and therapy of cancer is get more and more attention from public recent years. Compared to chemotherapy and radiotherapy which are harmful to human body and expensive, microwave imaging and microwave therapy as a relatively new therapy for detecting and curing cancer, have the advantages of high precision, long range radiation, less harmful to human body. Microwave imaging and microwave therapy research depend on the different electric characteristics parameters of normal tissue and tumor tissue, system solutions aiming to different kinds of cancer detection or treatment are designed. This work designs and manufactures a measurement system which is based on co-planar waveguide(CPW), this system is used to measure biological tissues precisely. The working frequency ranges from 1GHz to 5GHz, it is simulated by HFSS software. A de-embedding method depend on single fixture is proposed. This work uses Matlab software to process data. Vector network analyzer(VNA) is used to measure data. The measurement error of real part of relative permittivity is |Δε/ε|≤<5%, the error of loss tangent is|tanδ|≤0.05. This work lays the foundation of the circuits and systems of microwave detection and microwave therapy to cancer by measurement of different kind of biological tissues’ relative permittivityThe major research work includso:1.Review the development of measurement methods both in China and abroad. For co-planar waveguide(CPW) measurement fixture, this paper gives the static analysis of different kind of co-planar waveguide(CPW) structures, analyses the calculation methods of relative permittivity based on co-planar waveguide(CPW) fixture.2.Aiming to measure electric characteristics parameters of biologic tissue by co-planar waveguide(CPW) fixture,a single fixture de-embedding method is proposed. This method is verified by the electromagnetic simulation software HFSS.3.Manufacture measurement devices and build measurement system, use different biological tissue samples for measurement, read the measurement data by vector network analyzer(VNA) and process original data by computer calculation procedure. Then get the relative permittivity of material under test, and process these data and perform analyses.