DC Boosting Effect of Active Bias Circuits and Its Optimization for Class-AB InGaP–GaAs HBT Power Amplifiers

Yang, Youngoo; Choi, Kyoo Wan; Weller, K.P.

doi:10.1109/tmtt.2004.827021

Cited by 40 publications

(14 citation statements)

References 10 publications

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“…Transistor inputs are matched by two-section networks, and an emitter-buffered active bias circuit increases the DC collector current as output power increases [26], this enhancing thermal stability. Bias is slightly below class-A.…”

Section: :1 and 4:1 Series Combiners: Design And Resultsmentioning

confidence: 99%

Millimeter-Wave Series Power Combining Using Sub-Quarter-Wavelength Baluns

Park

Daneshgar

Griffith

et al. 2014

IEEE J. Solid-State Circuits

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We present a new millimeter-wave power-combining technique using transmission-line baluns which both connect transistor outputs in series and inductively tune the transistor output capacitances. The baluns are much shorter than a quarter-wavelength , hence are more compact and have less insertion loss than a balun. We introduce one topology providing an even number of series connections, including 2:1 and 4:1, and a second topology providing either an even or odd number of series connections. We then analyze segmented transformer power-combiners as a set of multi-conductor transmission-lines, and explore the relationship between transformer and transmission-line balun powercombiners. We demonstrate the technique with 2:1 and 4:1 seriesconnected designs implemented in a 0.25 m InP HBT process. At 86 GHz, a single-stage power amplifier (PA) using the 2:1 baluns exhibits 30.4% peak PAE, 20.37 dBm output power and 23 GHz 3-dB bandwidth from a 448 816 m die. A two-stage PA using the 2:1 baluns exhibits 30.2% PAE, and 23.14 dBm from an 824 816 m die. At 81 GHz, a two-stage PA with 4:1 series output power-combining exhibits 23.4% PAE, and 26.7 dBm (470 mW) from a 1,080 980 m die.Index Terms-Balun, mm-wave, power amplifier, power combiner, sub-quarter wavelength, transformer, transmission line.

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Section: :1 and 4:1 Series Combiners: Design And Resultsmentioning

confidence: 99%

Millimeter-Wave Series Power Combining Using Sub-Quarter-Wavelength Baluns

Park

Daneshgar

Griffith

et al. 2014

IEEE J. Solid-State Circuits

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“…The buffered bias circuit is composed of a transistor (Q1), a bias resistor , and a temperature compensation network . The should be chosen properly because it is directly related to the dc sourcing capability (DSC) [17]. When the RF signal is injected to the bias circuit, the base-emitter dc voltage of the power transistor is boosted by the second-order distortion of the transistor.…”

Section: Efficiency Improvement Using a New Bias Circuitmentioning

confidence: 99%

“…When the RF signal is injected to the bias circuit, the base-emitter dc voltage of the power transistor is boosted by the second-order distortion of the transistor. This is called as a dc boosting effect [17], which degrades the efficiency and linearity of the PA. To avoid the injection of the RF signal to the bias circuit, the value of should be large, but with a poor DSC.…”

Section: Efficiency Improvement Using a New Bias Circuitmentioning

confidence: 99%

Investigation of Intermodulation Distortion of Envelope Tracking Power Amplifier for Linearity Improvement

Moon

Cho

Kim

et al. 2015

IEEE Trans. Microwave Theory Techn.

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An intermodulation distortion of an envelope tracking (ET) power amplifier (PA) is investigated in this paper. For this purpose, the distortion characteristics are simulated based on the inter-connection model between the PA and supply modulator. For the sweet spot tracking ET operation, the fifth-order distortion is the most important one, which is generated by AM-PM nonlinearity. To reduce the distortion, the phase compensation network (PCN) is proposed. The efficiency of the PA is also improved by a properly designed bias circuit. For demonstration purposes, the PA and supply modulator are implemented using an InGaP/GaAs heterojunction bipolar transistor and a 0.18-m CMOS process, respectively. The ET PA is tested at 1.85 GHz using a long-term-evolution signal with 10-MHz bandwidth, a 7.5-dB peak-to-average power ratio, and 16 quadrature amplitude modulation. The ET PA with the proposed PCN and the bias circuit delivers a power-added efficiency of 44.3%, a gain of 23.4 dB, an evolved universal terrestrial radio access adjacent channel leakage ratio of 38.4 dBc, and an error vector magnitude of 1.8% at an average output power of 27 dBm. The multiband characteristics of the proposed ET PA are measured across 1.7-2.0 GHz. These results are achieved without any digitally supported techniques, indicating that the design approach is a promising technique for handset ET PA applications.Index Terms-Adjacent channel leakage ratio (ACLR), bias circuits, efficiency, envelope tracking (ET), intermodulation distortion (IMD), linearity, long-term evolution (LTE), phase compensation network (PCN), power amplifier (PA).

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“…To properly bias a BJT, both the sufficient base voltage and the current should be supplied by a proper biasing circuit, which is extremely important for power amplifiers based on BJTs. Therefore, the active biasing circuit able to supply sufficient base dc current as the input power level increases, must be utilized and properly designed [4]. Fig.…”

Section: Circuit Designmentioning

confidence: 99%

1.9GHz band highly linear 2-stage power amplifier MMIC based on InGaP/GaAs HBT

Kim

Choi

et al. 2009

2009 Asia Pacific Microwave Conference

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This paper describes a highly linear two-stage power amplifier monolithic microwave integrated circuit (MMIC) for the 1.9GHz band based on InGaP/GaAs heterojunction bipolar transistor (HBT). For achieving the highly linear power amplifier, the active biasing circuits have been optimized for the 1 st -and 2 nd -stages' third-order intermodulation distortion products (IMD3s) by cancelling them each other. Based on the optimized circuit parameters, the twostage power amplifier MMIC has been designed and fabricated to verify the cancellation effect over the 1.9GHz band. The fabricated MMIC exhibits a high third-order intercept point (OIP3) of 48dBm at an output power of 25dBm, an output power at 1dB compression point (P1dB) of 30dBm, a high PAE of 35.8% at P1dB, and a gain of 28.5dB under a supply voltage of 5V and a quiescent current of 345mA.Index Terms -Power amplifier, MMIC, InGaP/GaAs HBT, active bias circuit, IMD3.

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DC Boosting Effect of Active Bias Circuits and Its Optimization for Class-AB InGaP–GaAs HBT Power Amplifiers

Cited by 40 publications

References 10 publications

Millimeter-Wave Series Power Combining Using Sub-Quarter-Wavelength Baluns

Millimeter-Wave Series Power Combining Using Sub-Quarter-Wavelength Baluns

Investigation of Intermodulation Distortion of Envelope Tracking Power Amplifier for Linearity Improvement

1.9GHz band highly linear 2-stage power amplifier MMIC based on InGaP/GaAs HBT

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