Abstract
In this article, the co-design of novel self-packaged balanced bandpass filters (BPFs) integrated with the functionality of impedance transformation is presented for the first time. The proposed design is based on a modified branch-line structure, which is composed of two different branch lines and two identical coupled-line sections. Analysis results show that the considered filters can not only achieve Chebyshev equal-ripple responses with impedance transformation properties for the differential mode (DM) but also can efficiently improve the bandwidth of the common-mode (CM) rejection with resorting to this modified branch-line structure. Furthermore, according to the specified equal-ripple fractional bandwidth (FBW), in-band return loss (RL) level, and impedance transformation ratio {m} , the DM frequency response can be directly determined. Two design prototypes, the second-order balanced BPF with a 50-75-\Omega ( m= 1.5 ) impedance transformation and the third-order one with a 50-200-\Omega ( m= 4 ) impedance transformation, are implemented in self-packaged forms by using the multilayer liquid crystal polymer (LCP)-bonded printed circuit board (PCB) technology. Theoretical, simulated, and measured results are recorded in good agreement, well verifying the design concept.
Original language | English |
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Pages (from-to) | 4353-4361 |
Number of pages | 9 |
Journal | IEEE Transactions on Microwave Theory and Techniques |
Volume | 67 |
Issue number | 11 |
Early online date | 30 Aug 2019 |
DOIs | |
Publication status | Published - Nov 2019 |
Keywords
- Balanced filter
- impedance transformation
- liquid crystal polymer (LCP)
- self-packaged
ASJC Scopus subject areas
- Radiation
- Condensed Matter Physics
- Electrical and Electronic Engineering