Compact bandpass filter using novel transformer‐based coupled resonators on integrated passive device glass substrate

Abstract

This letter presents a transformer‐based coupled resonator structure to design a bandpass filter (BPF) using integrated passive device technology on glass substrate. The use of the transformer not only greatly reduces the size of the BPF but also easily uses the coupling to control the bandwidth of the filter. Using such a transformer‐based coupled BPF structure not only provides the advantage of compact size but also creates extra transmission zeros to enhance roll‐off rate or desired stopband rejection. Measured results verify the validity of this design methodology and show good agreement with simulated ones. For demonstration purpose, two example filters are implemented with different bandwidths. Both good performance and miniaturization are achieved for the proposed filters, and the expected transmission zeros are also observed. The filter can be embedded to wafer‐level three‐dimensional packaging and integration for wireless system‐in‐package applications. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:257‐262, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26498

Micro-Fabricated Resonator Based on Inscribing a Meandered-Line Coupling Capacitor in an Air-Bridged Circular Spiral Inductor

“…( B 3- d B ) is the 3- d B bandwidth. The meandered-line coupling structure is used to maximize the coupling length and, therefore, the coupling capacitance in a minimum area [ 16 ].…”

Second order bandstop and bandpass filters using transformers

“…Second order bandpass filters have also been constructed around transformers using coupled resonators [16,17], but their design is primarily reserved for microwave frequencies. All the while their performance is also highly dependent on the coupling coefficient between the resonators and resonator quality factor.…”

“…Usually when combined with filters, filtering typically precedes the transformer to shape or band-limit signals, as used in xDSL systems, the most common example being the filters in splitters for ADSL/POTS systems [8][9][10][11]. However, filters are rarely built around magnetic transformers with a few attempts in the literature [12][13][14][15][16][17]. In the work of [14,15] complex filters were constructed using linear transformers to build high order filters.…”

Very compact differential transformer-type bandpass filter with mixed coupled topology using integrated passive device technology

“…In the past several years, many studies have presented and proposed various topologies and design methods in which two primary methods are typically applied. One of the methods uses the transmission-line structure to realize the filter design [7][8][9][10], and the other standard method uses lumped LC-type structures [11][12][13][14][15][16]. Using the transmission-line structure avoids a complicated fabrication process, which reduces the cost of the entire chip.…”