Nonlinear effects in single-crystal silicon microresonators are analyzed with the focus on mechanical nonlinearities. The bulk acoustic wave (BAW) resonators are shown to have orders-of-magnitude higher energy storage capability than flexural beam resonators. The bifurcation point for the silicon BAW resonators is measured and the maximum vibration amplitude is shown to approach the intrinsic material limit. The importance of nonlinearities in setting the limit for vibration energy storage is demonstrated in oscillator applications. The phase noise calculated for silicon microresonator-based oscillators is compared to the conventional macroscopic quartz-based oscillators, and it is shown that the higher energy density attainable with the silicon resonators can partially compensate for the small microresonator size. Scaling law for microresonator phase noise is developed.

/pdf/nonlinear-limits-for-single-crystal-silicon-microresonators-w2dfxqtcvk.pdf

Nonlinear limits for single-crystal silicon microresonators

A comprehensive method of designing a broadband Doherty power amplifier is presented in this paper. The essential limitations of bandwidth extension of a Doherty power amplifier are discussed based on the proposed structure of the Doherty power amplifier, which also takes the output matching networks of both sub-amplifiers into account. The broadband matching is realized by applying the simplified real frequency technique with the desired frequency-dependent optimum impedances. GaN transistors were selected to implement the circuit structure.

Broadband Doherty Power Amplifier via Real Frequency Technique

A transistor-level, design-intensive overview of high speed and high frequency monolithic integrated circuits for wireless and broadband systems from 2 GHz to 200 GHz, this comprehensive text covers high-speed, RF, mm-wave and optical fiber circuits using nanoscale CMOS, SiGe BiCMOS and III-V technologies. Step-by-step design methodologies, end-of-chapter problems and practical simulation and design projects are provided, making this an ideal resource for senior undergraduate and graduate courses in circuit design. With an emphasis on device-circuit topology interaction and optimization, it gives circuit designers and students alike an in-depth understanding of device structures and process limitations affecting circuit performance.

High-Frequency Integrated Circuits

A 325-GHz ×18 frequency multiplier chain implemented in a fτ/fmax = 250 GHz/380 GHz evaluation SiGe heterojunction bipolar transistor technology is presented. The chain achieves a peak output power of -3 dBm and consists of a balanced doubler driven by two cascaded tripler stages. It operates from 317 to 328 GHz with a 0-dBm 18-GHz input signal and a 1.5-W power consumption. Additionally, 220- and 325-GHz doubler breakout circuits with integrated driver amplifiers are presented. The doublers reach an output power of -1 dBm at 220 GHz and -3 dBm at 325 GHz with a power dissipation of 630 and 420 mW, respectively.

Active 220- and 325-GHz Frequency Multiplier Chains in an SiGe HBT Technology

A low cost single-balanced mixer is designed using a newly designed 90/spl deg/ substrate integrated waveguide (SIW) 3-dB coupler, which takes the advantages of low cost, low profile, and high performance. An X-band single-balanced SIW mixer is designed and fabricated with a standard printed circuit board process. Measured conversion loss of 6.8dB and the wide-band response from 8.5 to 12GHz are presented.

Development of a low cost microwave mixer using a broad-band substrate integrated waveguide (SIW) coupler

Preface. Introduction, Fundamental Concepts, and Definitions. Solid-State Device Modeling. Harmonic-Balance analysis. Volterra-Series and Power-Series Analysis. Balanced Circuits. Diode Mixers. Diode Frequency Multipliers. Small-Signal Amplifiers. Power Amplifiers. Active Frequency Multipliers. Active Mixers. Oscillators. Index.

Stephen A. Maas

Papers

Nonlinear Microwave and RF Circuits