Research On Calculation Formula Of Single-feed Truncated-corner Circular Polarized And Capacitive-Feed Microstrip Antenna

As the essential front-end component in any radio system,antenna directly affects the performance of the radio system.Microstrip antenna has been widely used in various radio systems because of its advantages of small size,light weight,low cost,and easy to obtain circular polarization,so it is of great significance to study the calculation formula of microstrip antenna.Supported by the National Naturel Science Foundation of China(Foundation number:61401056),the calculation formulae of single-feed truncated-corner circular polarized microstrip antenna(CPMA)and capacitive feed rectangular patch microstrip antenna(RPMA)are respectively studied by the curve fitting technique and Taguchi method in this thesis.Details are as follows:(1)The synthesis formulae for directly calculating the dielectric substrate thickness,square patch dimension and corner-truncated size of the traditional single-feed truncated-corner CPMA are proposed,which simplify the design process and greatly improve the design efficiency of the antenna.To synthesize the tunable single-feed corner-truncated CPMA with the proposed formulae,the tunable single-feed corner-truncated CPMA is equivalent to the traditional single-feed truncated-corner CPMA,and the effective permittivity is solved by the fsolve function of MATLAB.Then,the relative dielectric constant for the dielectric substrate of the traditional single-feed truncated-corner CPMA is replaced by the effective permittivity,and the dielectric substrate thickness,square patch dimension and truncated-corner size of the equivalent model can be calculated by the proposed synthesis formulae.Next,the physical sizes of the tunable single-feed corner-truncated CPMA are obtained.Finally,synthesis formulae are validated by the comparison with electromagnetic simulation and measurement.(2)A new calculation formula for the resonant resistance of the tunable RPMA with a capacitive feed structure is proposed.The resonant resistnace of the tunable RPMA with a capacitive feed structure can be calculated by the proposed formula according to the patch size,dielectric constant,thickness of dielectric substrate and airgap.Finally,the formula is validated by the comparison with electromagnetic simulation and measurement.