A receiver comprising an amplification block (331a_1 to 331a_n; 700; 800; 900; AMPB_1 to AMPB_8) supporting carrier aggregation, the amplification block (331a 1 to 331a_n; 700; 800; 900; AMPB_1 to AMPB_8) comprising: a first amplifier circuit (600; 710; 810; 910) configured to receive a radio frequency input signal (RF IN) at a block node from an outside source, amplify the RF input signal (RF IN), and output the amplified RF input signal as a first RF output signal (RF OUT; RF OUT1), wherein the first amplifier circuit (600; 710; 810; 910) comprises: a first amplifier (AMP; AMP1) configured to receive the RF input signal (RF IN) through a first input node (X; X1) to amplify the RF input signal (RF IN); and a first feedback circuit (613; 713; 813; 913) coupled between the first input node (X; X1) and a first internal amplification node (Y; Y1) of the first amplifier (AMP; AMP1) to provide feedback to the first amplifier (AMP; AMP1), wherein the first amplifier (AMP; AMP1) comprises: a first transistor (611; 711; 811; 911) comprising a gate connected to the first input node (X; X1); and a second transistor (612; 712; 812; 912) comprising a drain connected to a first RF output node of the amplification block (331a_1 to 331a n; 700; 800; 900; AMPB_1 to AMPB_8), wherein a source of the second transistor (612; 712; 812; 912) is coupled to a drain of the first transistor (611; 711; 811; 911) at the first internal amplification node (Y; Y1), wherein the feedback circuit (613'; 713'; 813'; 913') selectively provides feedback to the first amplifier according to whether a mode of an RF integrated circuit is set to one of a wideband mode and a narrowband mode, and wherein the feedback circuit (613'; 713'; 813'; 913') comprises: a switching element (SWa) configured to be in an on state in the wideband mode and in an off state in the narrowband mode; at least one resistance element (R F; R FV) connected in series with the switching element (SWa); and at least one capacitor element (C F). a first amplifier circuit (600; 710; 810; 910) configured to receive a radio frequency input signal (RF IN) at a block node from an outside source, amplify the RF input signal (RF IN), and output the amplified RF input signal as a first RF output signal (RF OUT; RF OUT1), wherein the first amplifier circuit (600; 710; 810; 910) comprises: a first amplifier (AMP; AMP1) configured to receive the RF input signal (RF IN) through a first input node (X; X1) to amplify the RF input signal (RF IN); and a first feedback circuit (613; 713; 813; 913) coupled between the first input node (X; X1) and a first internal amplification node (Y; Y1) of the first amplifier (AMP; AMP1) to provide feedback to the first amplifier (AMP; AMP1), a first amplifier (AMP; AMP1) configured to receive the RF input signal (RF IN) through a first input node (X; X1) to amplify the RF input signal (RF IN); and a first feedback circuit (613; 713; 813; 913) coupled between the first input node (X; X1) and a first internal amplification node (Y; Y1) of the first amplifier (AMP; AMP1) to provide feedback to the first amplifier (AMP; AMP1), wherein the first amplifier (AMP; AMP1) comprises: a first transistor (611; 711; 811; 911) comprising a gate connected to the first input node (X; X1); and a second transistor (612; 712; 812; 912) comprising a drain connected to a first RF output node of the amplification block (331a_1 to 331a n; 700; 800; 900; AMPB_1 to AMPB_8), a first transistor (611; 711; 811; 911) comprising a gate connected to the first input node (X; X1); and a second transistor (612; 712; 812; 912) comprising a drain connected to a first RF output node of the amplification block (331a_1 to 331a n; 700; 800; 900; AMPB_1 to AMPB_8), wherein a source of the second transistor (612; 712; 812; 912) is coupled to a drain of the first transistor (611; 711; 811; 911) at the first internal amplification node (Y; Y1), wherein the feedback circuit (613'; 713'; 813'; 913') selectively provides feedback to the first amplifier according to whether a mode of an RF integrated circuit is set to one of a wideband mode and a narrowband mode, and wherein the feedback circuit (613'; 713'; 813'; 913') comprises: a switching element (SWa) configured to be in an on state in the wideband mode and in an off state in the narrowband mode; at least one resistance element (R F; R FV) connected in series with the switching element (SWa); and at least one capacitor element (C F). a switching element (SWa) configured to be in an on state in the wideband mode and in an off state in the narrowband mode; at least one resistance element (R F; R FV) connected in series with the switching element (SWa); and at least one capacitor element (C F).