US 11,742,829 B2
Multiplexer with filter having increased reflection characteristic
Tomoya Komatsu, Irvine, CA (US); Yiliu Wang, Irvine, CA (US); and Nan Wu, Irvine, CA (US)
Assigned to Skyworks Solutions, Inc., Irvine, CA (US)
Filed by Skyworks Solutions, Inc., Irvine, CA (US)
Filed on Aug. 25, 2020, as Appl. No. 17/2,456.
Claims priority of provisional application 62/892,954, filed on Aug. 28, 2019.
Prior Publication US 2021/0067139 A1, Mar. 4, 2021
Int. Cl. H03H 9/72 (2006.01); H03H 9/02 (2006.01); H03H 9/64 (2006.01); H03H 9/25 (2006.01); H04B 1/00 (2006.01)
CPC H03H 9/25 (2013.01) [H03H 9/02834 (2013.01); H03H 9/6406 (2013.01); H03H 9/6483 (2013.01); H04B 1/0057 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A multiplexer for filtering radio frequency signals, the multiplexer comprising:
a first filter having a first passband that is a lowest passband of all filters of the multiplexer, the first filter including a series inductor and a plurality of acoustic resonators coupled to a common node by way of the series inductor, the plurality of acoustic resonators starting with a first shunt acoustic resonator from the common node, and each ladder stage of the first filter including a shunt acoustic resonator of the plurality of acoustic resonators, the first filter coupled to the common node without an intervening switch;
a second filter coupled to the common node and having a second passband that is above the first passband, the series inductor and the first shunt acoustic resonator of the first filter together arranged to increase a reflection coefficient of the first filter in the second passband; and
a third filter coupled to the common node via a switch, the first, second, and third filters being included in the multiplexer, the third filter having a third passband that is a highest passband of all filters of the multiplexer.