Surface-mount cavity filter technology
01 January 2007
A method is proposed to realize cavity resonator filters for cellular frequencies in surface-mount technology. The cavity resonators can be produced by molding techniques and subsequently soldered onto a circuit board, where a stripline structure in the circuit board makes the coupling between the resonators. The molded parts for all resonators of a given filter can be identical. Means are proposed for dealing with the alignment accuracy of the mounting process. Temperature effects due to thermal expansion can be accounted for. A five-resonator bandpass filter has been designed using combined field and circuit simulation techniques.