Novel Design Approach for Ultra Compact, High Rejection LTCC Balanced Filter

In this paper a new approach for miniaturizing multilayer LTCC designs (Low Temperature Co-Fired Ceramics is proposed. Using the stacking options inside LTCC more consequently, a new very compact high-rejection balanced bandpass filter for WirelessLAN (based on IEEE 802.11a standard) is realized. The demonstrated filter performance is a very promising. With only 2.7 dB insertion loss in the band of interest and excellent out-of-band attenuation it occupies area less than 1.8 mm². Compared to designs with the same dielectric constant this downsizes by factor of two the required area without degrading the performance. The correlation between measurement and simulation results is a very good.