LC-Filters Using Film Components Built-in Multilayer Printed-Circuit Boards

The paper presents the results on using special foil-coated glass-fiber laminates allowing LC-filter main components (inductors and capacitors) to be manufactured in inner layers of multilayer printed-circuit boards (MPCB). As a result, an area on the MPCB surface becomes free for the allocation of other radio receiving device components. A technique for prototyping LC filters using film components built-in MPCB is developed. Using the MPCB technology LC-filters prototypes that are 10-layer boards with the inner layers made of the glass-fiber Farad Flex were developed and manufactured.

LC MPCB electric parameters were compared using the network analyzer intended for measuring characteristics such as S21 and S11. The parameters correction was performed by changing the MPCB outer layers structure and fine tuning the circuit using matching discrete LC-components. Each step of the development was controlled with a computer model developed on the basis of P-CAD2006 and AutoCard Applications.

The experimental results received for the LC-filters well agree with the theoretical model. The frequency response of the adjusted multilayer LC-filter as compared with the previous breadboard analog shows significant improvements in the at-tenuation parameters in HF band,0 narrowing the passband and reducing its ripple achieved after application of the devel-oped prototyping technology.