A wideband hybrid envelope tracking modulator utilizing a hysteretic-controlled three-level switching converter and a slew-rate enhanced linear amplifierer is presented. In addition to smaller ripple and lower losses of three-level switching converters, employing the proposed hysteresis control loop results in a higher speed loop and wider bandwidth converter, enabling over 80MHz of switching frequency. A concurrent sensor circuit monitors and regulates the flying capacitor voltage VCF and eliminates conventional required calibration loop to control it. The hysteretic-controlled three-level switching converter provides a high percentage of power amplifier supply load current with lower ripple, reducing the linear amplifier high-frequency current and ripple cancellation current, improving the overall system efficiency. A slew-rate enhancement (SRE) circuit is employed in the linear amplifier resulting in slew-rate of
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.
Four leaders in the field of microwave circuit design share their newest insights into the latest aspects of the technology The third edition of Microwave Circuit Design Using Linear and Nonlinear Techniques delivers an insightful and complete analysis of microwave circuit design, from their intrinsic and circuit properties to circuit design techniques for maximizing performance in communication and radar systems. This new edition retains what remains relevant from previous editions of this celebrated book and adds brand-new content on CMOS technology, GaN, SiC, frequency range, and feedback power amplifiers in the millimeter range region. The third edition contains over 200 pages of new material. The distinguished engineers, academics, and authors emphasize the commercial applications in telecommunications and cover all aspects of transistor technology. Software tools for design and microwave circuits are included as an accompaniment to the book. In addition to information about small and large-signal amplifier design and power amplifier design, readers will benefit from the book's treatment of a wide variety of topics, like: An in-depth discussion of the foundations of RF and microwave systems, including Maxwell's equations, applications of the technology, analog and digital requirements, and elementary definitions A treatment of lumped and distributed elements, including a discussion of the parasitic effects on lumped elements Descriptions of active devices, including diodes, microwave transistors, heterojunction bipolar transistors, and microwave FET Two-port networks, including S-Parameters from SPICE analysis and the derivation of transducer power gain Perfect for microwave integrated circuit designers, the third edition of Microwave Circuit Design Using Linear and Nonlinear Techniques also has a place on the bookshelves of electrical engineering researchers and graduate students. It's comprehensive take on all aspects of transistors by world-renowned experts in the field places this book at the vanguard of microwave circuit design research.
This work covers two bases, both performance optimization strategies and a complete introduction to mathematical procedures required for a successful circuit design. It starts from the basics of mathematical procedures and circuit analysis before moving on to the more advanced topics of system optimization and synthesis, along with the complete mathematical apparatus required. The authors have been at pains to make the material accessible by limiting the mathematics to the necessary minimum.
RF and mm-Wave Power Generation in Silicon presents the challenges and solutions of designing power amplifiers at RF and mm-Wave frequencies in a silicon-based process technology. It covers practical power amplifier design methodologies, energy- and spectrum-efficient power amplifier design examples in the RF frequency for cellular and wireless connectivity applications, and power amplifier and power generation designs for enabling new communication and sensing applications in the mm-Wave and THz frequencies. With this book you will learn: Power amplifier design fundamentals and methodologies Latest advances in silicon-based RF power amplifier architectures and designs and their integration in wireless communication systems State-of-the-art mm-Wave/THz power amplifier and power generation circuits and systems in silicon Extensive coverage from fundamentals to advanced design topics, focusing on various layers of abstraction: from device modeling and circuit design strategy to advanced digital and mixed-signal architectures for highly efficient and linear power amplifiers New architectures for power amplifiers in the cellar and wireless connectivity covering detailed design methodologies and state-of-the-art performances Detailed design techniques, trade-off analysis and design examples for efficiency enhancement at power back-off and linear amplification for spectrally-efficient non-constant envelope modulations Extensive coverage of mm-Wave power-generation techniques from the early days of the 60 GHz research to current state-of the-art reconfigurable, digital mm-Wave PA architectures Detailed analysis of power generation challenges in the higher mm-Wave and THz frequencies and novel technical solutions for a wide range for potential applications, including ultrafast wireless communication to sensing, imaging and spectroscopy Contributions from the world-class experts from both academia and industry
