A 500-MHz Bandwidth 7.5-mV<sub>pp</sub> Ripple Power-Amplifier Supply Modulator for RF Polar Transmitters

Kim, Chul; Chae, Chang-Seok; Yuk, Young-Sub; Thomas, Chris M.; Kim, Yi-Gyeong; Kwon, Jong-Kee; Ha, Sohmyung; Cauwenberghs, Gert; Cho, Gyu‐Hyeong

doi:10.1109/jssc.2018.2804043

“…[39,Eqn. (31,32)] take into account the mutual induction between the impressed current and the eddy current, which is proven correct by the comparison in [39, Fig. 9].…”

Section: Adjusting Factormentioning

confidence: 81%

“…Fig. 4.12 shows the comparison between our work and the prior arts, We do not use unrealistically low V DD 's, like some ETSM papers do without including any PA measurement [31,32].…”

Section: Et Tx Measurement Resultsmentioning

confidence: 99%

Envelope Tracking Supply Modulator with Trellis-Search-Based Switching and 160-MHz Capability

Leng

¹

,

Abidi

²

,

Mundlapudi

³

et al. 2022

IEEE J. Solid-State Circuits

8

0

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Envelope tracking is widely used to raise the efficiency of PAs. An envelope tracking supply modulator (ETSM) modulates PA's supply voltage to tracks the RF waveform's envelope, so that the PA will operate in saturation all the time. A hybrid amplifier is commonly used to realize the ETSM, which, in effect, partitions the envelope bandwidth into a low and high subband. An efficient switching buck converter tracks the low band. In parallel with it, an op-amp supplies the current in the high band. In prior arts, the hybrid amplifier is realized with feedback using a hysteresis comparator, whose output actuates the buck converter to respond to the changing envelope; the continuous-time op-amp makes up for the error. But a comparator-driven buck converter produces a slew-rate limited current that always lags the envelope waveform. This forces the op-amp to produce a larger current to correct the error, and the arrangement cannot guarantee that the buck converter switches no often than is absolutely necessary. We replace the hysteresis comparator with a novel trellis-search that, first, finds the optimal sequence to switch the buck converter to minimize the RMS current that the op-amp must deliver; second, to lower the loss from switching the capacitance of FETs, it penalizes a large number of switching events in the buck converter.Meanwhile, with a conventional on-chip hysteresis comparator, we can demonstrate ETSM operation up to 160 MHz modulation bandwidth. This is the widest bandwidth reported so far for any ETSM.ii The dissertation of Weiyu Leng is approved.

show abstract

“…However, [39,Eqn. (31,32)] imply that the series loss of a conductor will saturate after a corner frequency f 0 defined in [39, Eqn. (30b)].…”

Section: N/a]mentioning

confidence: 99%

Envelope-Tracking Supply Modulator with Trellis Search-Based Switching and 160MHz Capability

Leng

¹

,

Abidi

²

,

Mundlapudi

³

et al. 2021

2021 IEEE Custom Integrated Circuits Conference (CICC)

2

0

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Envelope tracking is widely used to raise the efficiency of PAs. An envelope tracking supply modulator (ETSM) modulates PA's supply voltage to tracks the RF waveform's envelope, so that the PA will operate in saturation all the time. A hybrid amplifier is commonly used to realize the ETSM, which, in effect, partitions the envelope bandwidth into a low and high subband. An efficient switching buck converter tracks the low band. In parallel with it, an op-amp supplies the current in the high band. In prior arts, the hybrid amplifier is realized with feedback using a hysteresis comparator, whose output actuates the buck converter to respond to the changing envelope; the continuous-time op-amp makes up for the error. But a comparator-driven buck converter produces a slew-rate limited current that always lags the envelope waveform. This forces the op-amp to produce a larger current to correct the error, and the arrangement cannot guarantee that the buck converter switches no often than is absolutely necessary. We replace the hysteresis comparator with a novel trellis-search that, first, finds the optimal sequence to switch the buck converter to minimize the RMS current that the op-amp must deliver; second, to lower the loss from switching the capacitance of FETs, it penalizes a large number of switching events in the buck converter.Meanwhile, with a conventional on-chip hysteresis comparator, we can demonstrate ETSM operation up to 160 MHz modulation bandwidth. This is the widest bandwidth reported so far for any ETSM.ii The dissertation of Weiyu Leng is approved.

show abstract

“…Various techniques, including supply modulation techniques, have been proposed to improve the PA efficiency at the large OPBO . The envelope tracking (ET) technique is a type of the supply modulation technique and has been used to improve the PA efficiency using the supply modulator that supplies the processed envelope signal to the PAs as the supply voltage [8][9][10][11][12][13][14][15][16][17][18][19][20]. The basic structure of the hybrid supply modulator for the ET technique consists of the high-speed linear amplifier stage and the high-efficiency switching amplifier stage.…”

Section: Introductionmentioning

confidence: 99%

DSS modulator using the SIDO dc−dc converter for the CMOS RF PA integrated circuit

Oh

¹

,

Bae

²

,

Oh

³

et al. 2019

IET Microwaves, Antennas & Propagation

3

0

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A dynamic supply switching (DSS) modulator using a single‐inductor dual‐output (SIDO) dc−dc converter for complimentary metal‐oxide semiconductor (CMOS) radio frequency (RF) power amplifier (PA) integrated circuits is presented. The DSS modulator consists of the SIDO dc−dc converter and a supply switching circuit (SSC). The SIDO dc−dc converter requires only one off‐chip inductor while generating two of the dc voltages. The SSC dynamically switches the high and low dc voltages according to the modulated signal envelope. The supply switching control voltage, which is generated from the envelope, is optimised for maximum efficiency improvement. The proposed DSS PA using the SIDO dc−dc converter and the SSC was fabricated using a 0.18 μm CMOS process for a 1.75 GHz frequency band and a long‐term evolution (LTE) application. For the LTE 16‐QAM signal with the peak‐to‐average power ratio (PAPR) of 7.5 dB, the measured efficiency of the DSS PA is 33.8% at the average output power of 21 dBm, thereby satisfying the adjacent channel leakage power ratio (ACLR) level of −30.1 dBc. The measured efficiency of the DSS PA at an average output power of 15 dBm is 24.8%, which is higher than that of the stand‐alone PA by 13.3%.

show abstract

A 500-MHz Bandwidth 7.5-mV_pp Ripple Power-Amplifier Supply Modulator for RF Polar Transmitters

Cited by 11 publications

References 21 publications

Envelope Tracking Supply Modulator with Trellis-Search-Based Switching and 160-MHz Capability

Envelope Tracking Supply Modulator with Trellis-Search-Based Switching and 160-MHz Capability

Envelope-Tracking Supply Modulator with Trellis Search-Based Switching and 160MHz Capability

DSS modulator using the SIDO dc−dc converter for the CMOS RF PA integrated circuit

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A 500-MHz Bandwidth 7.5-mVpp Ripple Power-Amplifier Supply Modulator for RF Polar Transmitters

Cited by 11 publications

References 21 publications

Envelope Tracking Supply Modulator with Trellis-Search-Based Switching and 160-MHz Capability

Envelope Tracking Supply Modulator with Trellis-Search-Based Switching and 160-MHz Capability

Envelope-Tracking Supply Modulator with Trellis Search-Based Switching and 160MHz Capability

DSS modulator using the SIDO dc−dc converter for the CMOS RF PA integrated circuit

Contact Info

Product

Resources

About

A 500-MHz Bandwidth 7.5-mV_pp Ripple Power-Amplifier Supply Modulator for RF Polar Transmitters