Research On Silicon-based Broadband Multi-mode Frequency Synthesizer Integrated Circuits

With the rapid development of wireless technology and integration technology,the silicon-based frequency synthesizer is widely used due to its low cost and high integration.As a key module in wireless systems,the frequency range and phase noise performances of frequency synthesizer mainly determine the performance of wireless systems.With the frequency rising to millimeter-wave bands,the design of on-chip frequency synthesizers meets many challenges.In this thesis,the principle and design method of frequency synthesizer are deeply studied.Then,a number of broadband multimode oscillators and PLL architectures and technologies are proposed.A series of oscillators and PLLs are developed based on advanced silicon-based CMOS technology.All of them achieve state-of-the-art performances.The main contributions and innovations of this thesis are as follows:1.Millimeter-wave broadband low-phase-noise oscillator.Aiming at the design challenge of millimeter-wave broadband high performance oscillator,a dual-mode voltage waveform-shaping oscillator is proposed.Using mode-switching multi-order resonator,the voltage waveform-shaping in two frequency modes is realized in millimeter-wave band for the first time.Then,the phase noise can be reduced in wide frequency range.Based on this technology,a broadband oscillator is designed and implemented in 28-nm CMOS process.The frequency range is from 20.7 to 31.8 GHz.At 10 MHz frequency offset,the phase noise is–127.4 d Bc/Hz.The corresponding Fo M is 188.2 d Bc/Hz.2.Resonance-boosting multi-core oscillator.In order to achieve more than two operation modes using a compact chip size,an E-M mixed-coupling mode-switching technique is proposed.Using E-M mixed-coupling multi-stage resonator and two-dimensional mode-switching circuit,the multi-core oscillator can achieve phase noise suppression and bandwidth expansion at the same time.As a result,the phase noise is reduced by nearly 6 d B within the quad-mode operation frequency.A millimeter-wave oscillator with a frequency range of 18.6 to 40.1 GHz and a tuning range of 73.2%is realized in 40-nm CMOS process,which achieves the state-of-the-art Fo M_Tbetter than 200 d Bc/Hz.3.Terahertz broadband push-push oscillator.In order to meet the requirements of terahertz oscillator’s wide tuning range and miniaturization,a push-push oscillator using transformer-based equivalent-capacitance expansion technique is proposed.The core size is only 0.01 mm~2.Then,a dual-mode harmonic-extraction oscillator based on L-C mode-switching technique is developed.The oscillator can obtain wideband second-harmonic oscillation frequency and relax the tradeoff between frequency range and phase noise performance.An oscillator with a center frequency of 169.6 GHz and a tuning range of 21.7%is designed in 28-nm CMOS process.The Fo M_Tat 10 MHz offset is 180.6 d Bc/Hz.4.Millimeter-wave mode-switching quadrature oscillator.The quadrature oscillator would introduce the tradeoff between phase noise and phase error,especially at millimeter-wave.A quadrature oscillator technology based on mode-switching topology is proposed.The optimization of quadrature phase error and phase noise can be realized simultaneously in wide frequency range.Meanwhile,the flicker noise up-conversion of the quadrature-coupling devices can be suppressed.Based on this technology,a wideband quadrature oscillator is designed and implemented in 28-nm CMOS process,achieving a frequency range from 22.8 to 33.9 GHz and a quadrature phase error of0.5°to 1.2°.5.Millimeter-wave broadband low-phase-noise PLL.To overcome the high complexity and high power consumption of millimeter wave broadband PLL,a cascaded multi-mode sub-sampling PLL architecture is proposed.The PLL consists of a fractional-N PLL cascaded with a divider-less mode-switching sub-sampling loop.Thus,the structure has the merits of robust frequency control and low loop noise.Moreover,the mode-switching mechanism can support the wide frequency locking range without divider in the sub-sampling loop.Based on this architecture,a millimeter-wave broadband quadrature fractional-N frequency synthesizer is designed and fabricated in28-nm CMOS process.The operating frequency band covers 22.8 to 33.9 GHz,the integral jitter is 306 fs,and the power consumption is 41.7 m W.With a conventional 52MHz reference crystal oscillator,the proposed PLL can reduce the system cost.