A Broadband Injection-Locking Class-E Power Amplifier

Lin, Chi-Hsien; Chang, Hong-Yeh

doi:10.1109/tmtt.2012.2209456

Cited by 15 publications

(7 citation statements)

References 21 publications

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“…Together with an inductor at the input, it acts as an oscillator, injection locked to the driver frequency. Furthermore, as the driver is essentially driving an ideal LC tank, it saves power in the driver [12], [13]. However, this topology faces several drawbacks: (a) A reduction in power consumption of the driver and ILO demands high Q of the input resonant tank, but a higher Q leads to a reduced injection lock-range and modulation bandwidth.…”

Section: A Limitations Of Dual-tank Ilpamentioning

confidence: 99%

“…(d) The use of an additional inductor at the input increases area. (e) The negative input conductance of the PA transistor also depends upon the driver output power, further complicating the design [12], [13].…”

Section: A Limitations Of Dual-tank Ilpamentioning

confidence: 99%

“…The worst-case scenario occurs for the weakest injection locking when the desired symbol rate is to be maintained for K 0 , i.e., when the LSB of ICDPA locks the full width of the PO. The maximum symbol rate S = S 0 supported by K 0 , from (10) and (13), is given by…”

Section: K Minw01 K Minw02 K Minw03mentioning

confidence: 99%

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Injection Locking in Switching Power Amplifiers

2020

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In this work, injection locking in switching power amplifiers (PAs) is studied. Traditionally, injection-locked PAs (ILPAs) have supported phase modulation, with injection locking used primarily to improve the power-added efficiency by reducing the power required to drive the ILPA. Since the output power in conventional ILPA architectures is mainly contributed by the locked oscillator in an ILPA, the amplitude modulation is difficult to achieve unless supply modulation is employed. In the ILPA presented in this work, it is shown that by injection locking a switching PA and a power oscillator, improvement in both power-added efficiency and drain efficiency can be achieved as compared to just a switching PA. Moreover, amplitude modulation at a fixed supply voltage is achieved using an RF-DAC approach to scale both the switching PA and the locked oscillator. This approach employs variable injection-strengths varying from ≤ 1 (weak injection locking) to > 1 (strong injection locking) to achieve the required power back-off. Accordingly, new formulations are introduced to extend the existing injection locking theory for injection strengths > 1 case in ILPAs. Benefits of a larger injection strength on lock-range, maximum allowable symbol rate, AM-PM distortion and phase noise performance for an ILPA is provided. An ILPA is designed to support 64-QAM and implemented in a standard 65-nm bulk CMOS process. A peak drain efficiency of 42.7% and power-added efficiency of 40% is measured at the highest output power of 23 dBm, operating from a 1.45 V PA power supply at 2.5 GHz. Modulation tests with 5/50 MSym/s 64-QAM signals achieve the measured RMS EVM of 1.9%/3.1% with the average output power, drain efficiency and power-added efficiency of 18.1 dBm, 27.9% and 25.8% at 2.5 GHz, respectively. INDEX TERMS AM-PM, CMOS integrated circuits, efficiency, inverse class-D PA (ICDPA), injection locking, injection-locked power amplifier (ILPA), power amplifier (PA), power oscillator, polar modulation, switching circuits.

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Section: A Limitations Of Dual-tank Ilpamentioning

confidence: 99%

Section: A Limitations Of Dual-tank Ilpamentioning

confidence: 99%

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Injection Locking in Switching Power Amplifiers

2020

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“…Injection-locking is a phenomenon in which an injected signal pulls an otherwise selfoscillating circuit to the signal frequency [11:376]. This phenomenon can be leveraged to improve the gain -and subsequently, the PAE -of power amplifiers by decoupling the large power transistors with high input capacitances from the input signal [16:167], [19]. The input signal is instead used to drive small injection transistors that pull a power oscillator to the desired frequency.…”

Section: Chapter 4: Injection Lockingmentioning

confidence: 99%

“…Two possible input matching networks for a typical power transistor 19. Another approach is to use an inductor connected in parallel with the gate input capacitance to resonate out the reactive component of the transistor input impedance.…”

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confidence: 99%

A Fully Integrated Distributed Active Transformer Power Amplifier with Injection Locking

Laughton¹

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This work explores the design of a novel integrated RF power amplifier in IBM's 0.13 micron RF CMOS process. Through a combination of architectures, the series output transformer coupling of a distributed active transformer (DAT) topology is paired with a gain enhancing injection-locking architecture in an attempt to realize a combination of high output power, gain and efficiency; while minimizing die area and supply voltage. The DAT topology simultaneously provides high quality impedance transformation and power combining in the output network that can be used to overcome the low breakdown and high knee voltages-and lossy on-chip passive components-inherent to silicon processes. While improving the overall maximum output power, the large transistors of the DAT require large amplitude driving signals which limit the gain of the system. The injection-locking technique can be used to reduce the input drive voltage for an amplifier circuit, thereby increasing the gain and, consequently, the power-added efficiency. By employing this novel hybrid architecture, the proposed injection-locking DAT power amplifier achieves a P1dB of 25.94 dBm with a maximum gain of 14.5 dB and peak PAE of 22% from a 1.5 V dc supply voltage (in simulation). The measurement results show discrepancies from the simulated results provided, and several hypotheses as to the cause of these differences are explored.

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