Radio Frequency Connector Design And Testing Study

To satisfy the ever developing of telecommunication, as the system key component radio frequency connectors are going in the direction of miniaturization, high operation frequency, high power handling capability, especially for base station applications where there are strict requirements of low voltage standing wave ratio, radio frequency leakage, power handling capability and etc. This dissertation firstly briefly summarizes the transmission theory and equations used in RF connector and focuses on explaining the transmission line equations and its resolutions including its working status.Since there are not many materials on scatter parameters simulations in China, this dissertation studies Ansoft HFSS simulations such as electrical length, return loss, insertion phase, the way to lower S1 1through TDR plot evaluation and capacitive and inductive discontinuity compensation. Due to the wide use of SMA connectors, and its structure which can be referenced for other connectors, standard compensation dimensions are developed for common used barb and knurl captivation on contact. This results 10-15 dB return loss improvement. They can be practically used for the whole series SMA design. Besides scattering parameters simulations, HFSS can also do power and heat simulations by a module called Ephysics. This article studies the impact on power handling capability due to various load condition and heat dissipation factors. Through locating the hottest point, improvement can be accomplished.With the simulation and theoretical research work, one SMA cable assembly and its PCB connector are developed with very strict requirement on VSWR and cable assembly electrical length. The project works on how to design the connectors to lower return loss. Analysis is done on the reasons why return loss is generated. In connector design, multiple steps, supports and dielectric are the main reasons for VSWR. Through careful analysis by HFSS TDR plot, VSWR is minimized. Meanwhile, dielectric withstanding voltage and peak power is calculated between the body and contact to ensure it meets technical specifications. For PCB connector, a test board is developed so samples can be soldered to measure its parameters. The research also includes comparing different methods of board connector testing, including adaptor, special designed PCB and TRL calibration method, as well as their application. This will have broad reference value for board type connector testing. Furthermore, it further studies the mechanical machining and contact assembly tolerance's impact on electrical performance. By using partial differentiation, equations are developed to calculate the exact effect.After the design work is completed, FAI samples are made to measure their compliance to the design specifications. Then, failure mode is analyzed with PNA measurement and compared as against simulations result. After correction, the batch of the samples is completed and risk is relegated from later formal validation.Finally, a full design verification and validation test is done on the batch of the samples in terms of electrical, mechanical and environmental performance. Conclusion is made that the final product can meet the technical specification defined on the contract and it's ready for delivery.