Design of compact LTCC bandpass filter with high process tolerance using meander line coupled inductor

Fast prototype‐based design approach to highly miniaturized LTCC BPFS for WLAN/WIMAX dual‐mode applications

“…The previous researches on the miniaturization of LTCC BPFs for wireless communication applications mainly include the second‐order and third‐order designs. The second‐order designs can have a relatively small (typically 2520 or 2012) size, but they have a low roll‐off rate inherently.…”

“…The second‐order designs can have a relatively small (typically 2520 or 2012) size, but they have a low roll‐off rate inherently. This disadvantage was improved by using meander line coupled inductor to replaced traditional straight line coupled inductor to reduce filter size or adding the grounding capacitor for creating transmission zeros in the stopband or a method of using admittance inverters to design modified Chebyshev BPF with one transmission zero located at higher stopband . Three methods still have difficulties in further shrinking the filter size because the former still require a coupling capacitor, the middle require a large‐value grounding capacitor, and the latter require two extra inductors.…”