Microwave power amplifier efficiency improvement with a 10 MHz HBT DC-DC converter

Abstract

This paper presents a technique for raising power efficiency in portable wireless transmitters by integrating a variable voltage output dc-dc converter together with a MESFET F W power amplifier. Significant increases in power efficiency are obtainable over a large range of output power levels. The system includes an envelope detector, a closed feedback loop, and a pulse width modulator operating at 10 MHz. A 300mW transmitter is shown for which battery life can be extended by over 1.4 times. PowerHigh wastf!d ef'ficierq

Linearity and Efficiency Strategies for Next‐Generation Wireless Communications

“…EER uses a combination of a high-efficiency switched-mode PA with an envelope remodulation circuit [7][8][9][10][11]; ET utilizes a linear PA and a controlled supply voltage, which closely tracks the output envelope. When the supply voltage tracks the instantaneous output envelope, it is known as wide-bandwidth ET (WBET) [12][13][14][15]; when the supply voltage tracks the long-term average of the output envelope, it is known as average ET (AET) [16,17]. AET techniques are especially useful for power control schemes, such as the reverse link in CDMA, where the long-term variation in average power is much greater than 20 dB [18].…”

Bias Switching Amplifier Design and Linearization

“…To verify the proposed concept, some amplifiers are designed and used for the linearized power amplifier system. [4,5] In this paper, a technique for high efficiency amplifier design by using bias switching is proposed, and the operating principle and the simulation of the proposed technique is described in section 2. The efficiency performance measurement of the proposed bias switching amplifier is im section 3.…”

Two-stage adaptive power amplifier MMIC for handset applications

“…The techniques for achieving the high efficiency at the most probable output power are being highlighted recently as the most significant issues in designing power amplifiers for mobile handsets. The power amplifier employing DC-DC converters [2]- [4] operated in near saturation region at all power levels with a variable supply voltage to the input power, generating higher efficiency. Switched gain stage power amplifier [5] bypasses the power stage for the high efficiency at the low output power level.…”