A balance filter with DC supply for Bluetooth™ module

In this paper a balance filter is useful for Bluetooth™ application whether it is embedded or discrete type. The filter schematic that consists of two close resonators is well known. This combline filter can design for compact size and low cost realization. Also it is shown that the structure of combline filter is very useful in low temperature co-fired ceramic technology (LTCC). The design method for a balun is based on Marchand balun. But the difference is that it has loading capacitor. The proposed design method and equivalent circuit can make it easy to design the balun with DC supply. Also it is independent for design of the DC power plane. Bluetooth™ module using suggested design in this paper have good agreement with simulated data.