PROJECT TITLE :

Coupling-Matrix-Based Design of High-$Q$ Bandpass Filters Using Acoustic-Wave Lumped-Element Resonator (AWLR) Modules

ABSTRACT:

This paper presents an inspired and easy coupling-matrix-primarily based synthesis methodology for the design of a replacement category of bandpass filters (BPFs) that employ hybrid acoustic-wave-lumped-element resonator (AWLR) modules with improved out-of-band isolation (IS). The proposed BPFs feature quasi-elliptic-kind frequency response—formed by $N$ poles and $2N$ transmission zeros (TZs) for an $N$th-order transfer perform, compact physical size, and high effective quality factors $(Q_rm eff)$ of the order of 1000. Despite the utilization of acoustic wave (AW) resonators, passbands exhibiting fractional bandwidths (FBWs) that are no longer limited by the electromechanical coupling coefficient $(k_t^2)$ of the constituent AW resonators are obtained. A coupling-matrix-primarily based model of a multi-mode AW resonator is also reported. It facilitates the incorporation of high- and low-frequency spurious modes that are gift during a realistic filter response thus that they can be anticipated at the synthesis and simulation levels. For proof-of-concept validation functions, 2 BPF prototypes at 418 MHz created of commercially-available surface acoustic wave (SAW) resonators and surface mounted devices (SMD) were engineered and measured. They perform initial- (one pole and 2 TZs) and second-order (two poles and four TZs) transfer functions with measured passband insertion losses (IL) between a pair of.4–5.4 dB, $Q_rm eff$ between 160zero–190zero, 3-dB absolute bandwidths starting from 0.fifty two to 1 MHz (i.e., 1.6–three.2 times $k_t^2$), and minimum IS levels between twenty five–46 dB.