TY - GEN
T1 - A two-phase switching hybrid supply modulator for polar transmitters with 9% efficiency improvement
AU - Wu, Ying
AU - Mok, Philip K.T.
PY - 2010
Y1 - 2010
N2 - Emerging polar transmitters for highly efficient and linear power amplifiers (PAs) demand for high-efficiency, high-bandwidth and low-ripple supply modulators. In [1], a linear regulator is used; however, its efficiency is low at low power levels. A switched-mode power supply (SMPS) is used in [2]; but the high switching loss due to high switching frequency (necessary for high bandwidth) limits the maximum efficiency to ∼76%. A hybrid amplifier (HA) topology combining both linear amplifier (LA) and switching amplifier (SA) is used in some recent work [3, 4]. In this topology, a high-bandwidth LA replicates the input envelope voltage Vin at its output V o; while the high-efficiency SA supplies most of the load current within its bandwidth. Yet, the tracking bandwidth is finite in [3]; and the LA in [4] needs to supply most of the high-frequency load current due to the exceptionally large inductor (20μH) used for realizing small output ripple; and therefore, limiting the dynamic efficiency. Figure 10.1.1 shows the proposed wideband HA featuring two-phase switching (2PHSW) for reducing ripple and improving static efficiency, and a feedforward bandpass filter (FF-BBF) for enhancing dynamic efficiency.
AB - Emerging polar transmitters for highly efficient and linear power amplifiers (PAs) demand for high-efficiency, high-bandwidth and low-ripple supply modulators. In [1], a linear regulator is used; however, its efficiency is low at low power levels. A switched-mode power supply (SMPS) is used in [2]; but the high switching loss due to high switching frequency (necessary for high bandwidth) limits the maximum efficiency to ∼76%. A hybrid amplifier (HA) topology combining both linear amplifier (LA) and switching amplifier (SA) is used in some recent work [3, 4]. In this topology, a high-bandwidth LA replicates the input envelope voltage Vin at its output V o; while the high-efficiency SA supplies most of the load current within its bandwidth. Yet, the tracking bandwidth is finite in [3]; and the LA in [4] needs to supply most of the high-frequency load current due to the exceptionally large inductor (20μH) used for realizing small output ripple; and therefore, limiting the dynamic efficiency. Figure 10.1.1 shows the proposed wideband HA featuring two-phase switching (2PHSW) for reducing ripple and improving static efficiency, and a feedforward bandpass filter (FF-BBF) for enhancing dynamic efficiency.
UR - http://www.scopus.com/inward/record.url?scp=77952197481&partnerID=8YFLogxK
U2 - 10.1109/ISSCC.2010.5433989
DO - 10.1109/ISSCC.2010.5433989
M3 - Conference contribution
AN - SCOPUS:77952197481
SN - 9781424460342
T3 - Digest of Technical Papers - IEEE International Solid-State Circuits Conference
SP - 196
EP - 197
BT - 2010 IEEE International Solid-State Circuits Conference, ISSCC 2010 - Digest of Technical Papers
T2 - 2010 IEEE International Solid-State Circuits Conference, ISSCC 2010
Y2 - 7 February 2010 through 11 February 2010
ER -