US 12,255,674 B2
Constant-phase attenuator techniques in radio frequency front end (RFFE) amplifiers
Xingyi Hua, San Diego, CA (US); Bassel Hanafi, San Diego, CA (US); Karthik Tripurari Jayaraman, San Diego, CA (US); and Francesco Gatta, San Diego, CA (US)
Assigned to QUALCOMM Incorporated, San Diego, CA (US)
Filed by QUALCOMM Incorporated, San Diego, CA (US)
Filed on Jan. 20, 2022, as Appl. No. 17/580,320.
Prior Publication US 2023/0231586 A1, Jul. 20, 2023
Int. Cl. H03F 1/22 (2006.01); H03F 1/56 (2006.01); H04B 1/04 (2006.01)
CPC H04B 1/0483 (2013.01) [H03F 1/565 (2013.01); H03F 2200/451 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An amplifier having an input and an output and comprising:
a high gain path coupled between the input and the output and comprising active circuitry; and
a low gain path coupled between the input and the output and comprising phase-shifting circuitry,
wherein the phase-shifting circuitry is configured to shift a phase of an input signal within the low gain path such that the phase of an output signal at the output of the amplifier from the low gain path approximately matches a phase of the output signal at the output of the amplifier from the high gain path, and wherein a gain of the high gain path is higher than a gain of the low gain path, wherein the phase shifting circuitry comprises an inductor coupled in series between the input and the output of the amplifier, the phase-shifting circuitry further comprising a first shunt capacitor and a second shunt capacitor, the inductor coupled between the first shunt capacitor and the second shunt capacitor, wherein the inductor is tapped by a third shunt capacitor.