US 11,671,147 B2
Contactless card reading employing gain and attenuation control
Hyunjae Kang, Seoul (KR)
Assigned to SAMSUNG ELECTRONICS CO., LTD., Suwon-si (KR)
Filed by SAMSUNG ELECTRONICS CO., LTD., Suwon-si (KR)
Filed on Mar. 21, 2022, as Appl. No. 17/699,459.
Application 17/699,459 is a continuation of application No. 17/023,923, filed on Sep. 17, 2020, granted, now 11,283,483.
Claims priority of application No. 10-2019-0168535 (KR), filed on Dec. 17, 2019.
Prior Publication US 2022/0209824 A1, Jun. 30, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. H04B 5/00 (2006.01); H04B 5/02 (2006.01); H04B 1/38 (2015.01)
CPC H04B 5/0031 (2013.01) [H04B 5/0037 (2013.01); H04B 5/0062 (2013.01); H04B 5/0093 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A contactless integrated circuit (IC) card reader configured to communicate with a contactless IC card, comprising:
an antenna circuit;
a transmission circuit configured to generate a carrier signal;
a variable amplifier configured to amplify the carrier signal at an amplification gain and to output the amplified carrier signal to the antenna circuit as a transmission signal;
a variable attenuator configured to attenuate a receive signal received through the antenna circuit at an attenuation ratio;
a reception circuit configured to filter the carrier signal from the attenuated receive signal and to generate a filtered receive signal; and
a controller configured to compare an amplitude of the filtered receive signal with a reference level, and to control both the amplification gain of the variable amplifier and the attenuation ratio of the variable attenuator based on a result of the comparison.