Design for Acoustic Wave Multiplexers With Single Inductor Matching Network Using Frequency Response Fitting Method

Abstract

This study proposes a new acoustic wave (AW) multiplexer topology with a single-inductor matching network for carrier aggregation (CA) in the fifth-generation communication systems. To satisfy the desired specifications of all the multiplexer ports based on ladder-type filters, the frequency response fitting method (FRFM) is proposed to obtain the BVD parameters for each AW resonator. Using the proposed computer-aided method, a parameter solution can be obtained under practical design limitations, such as the selection of the piezoelectric material, properties of the manufacturing process, and used circuit topology. Furthermore, a measurement of a band 1 and 3 surface acoustic wave (SAW) multiplexer is set up to confirm the feasibility of the proposed FRFM. The designed SAW multiplexer based on the lithium tantalate with Euler angle (0, −38, 0), 42 ｏ YX-LiTaO3, is arranged. The designed quadplexer achieves high selectively with a return loss (RL), stopband reflection, and isolation better than −12 dB, −43 dB, and −50 dB, respectively, in a 2.15 × 2.65 mm 2 occupation. The measurement results confirm the feasibility of the multiplexer topology and the proposed FRFM. The approach is also extended to a quadplexer design with band 4 and 25 and a hexaplexer design with band 1, 3, and 7 for CA applications, demonstrating its flexibility and simplicity.INDEX TERMS acoustic wave components, filter synthesis, MEMS, microwave components, microwave filters, multiplexers, optimization methods, SAW devices.

Design for SAW Antenna-Plexers with Improved Matching Inductance Circuits

“…Figure 12 shows the IDT structure of a single-port resonator. To extract the physical parameters of the structure, the experimental data and numerical curve fitting are required to predict the characteristics of a SAW resonator [ 22 ]. The relationship between pitch ( p ) and is plotted using the experimental data, which were measured by the manufacturer, and the curve is shown in Figure 13 .…”

“…Given the number of IDT pairs ( ) and gratings ( ), the two main physical parameters that affect the structural characteristics are the pitch width ( p ) and the aperture ( W ). Using the method of a previous study [ 22 ] and Section IV.A., if = 200 and = 20, the values of p and W are listed in Table 5 . Similarly, the values for the physical parameters of the IDT structure for the diplexer are determined and listed in Table 6 .…”

“…The desired mBVD parameters that meet the frequency response solution can be solved using a systematic optimization algorithm [ 22 ]. These are converted to various physical parameters for the SAW resonators [ 18 ].…”

“…The eight SAW resonators and the matching circuits for the extractor in Figure 2 are optimized using the pattern search method [ 22 ]. Table 3 shows the mBVD model parameter values for the optimized extractor with two matching inductors: L 1 = 4.7 nH and L 2 = 6.8 nH.…”