A 47 GHz Cross-Coupled VCO Employing High- Island-Gate Varactor for Phase Noise Reduction

A 47 GHz $LC$ cross-coupled voltage controlled oscillator (VCO) employing the high-$Q$ island-gate varactor (IGV) based on a 0.13 $mu{rm m}$ RFCMOS technology is reported in this work. To verify the improvement in the phase noise, two otherwise identical VCOs, each with an IGV and a conventional multi-finger varactor, were fabricated and the phase noise performance was compared. With $V_{DD}$ of 1.2 V and core power consumption of 3.86 mW, the VCOs with the IGV and the multi-finger varactor have a phase noise of $-$95.4 dBc/Hz and $-$91.4 dBc/Hz respectively, at 1 MHz offset, verifying the phase noise reduction with the introduction of the high-$Q$ IGV. The VCO with IGV exhibited an output power of around $-$15 dBm, leading to a FoM of $-$182.9 dBc/Hz and a tuning range of 3.35% (45.69 to 47.22 GHz).      

A Phase-Locked Loop With Injection-Locked Frequency Multiplier in 0.18-$mu{hbox{m}}$ CMOS for $V$ -Band Applications

In this paper, a novel CMOS phase-locked loop (PLL) integrated with an injection-locked frequency multiplier (ILFM) that generates the $V$-band output signal is proposed. Since the proposed ILFM can generate the fifth-order harmonic frequency of the voltage-controlled oscillator (VCO) output, the operational frequency of the VCO can be reduced to only one-fifth of the desired frequency. With the loop gain smaller than unity in the ILFM, the output frequency range of the proposed PLL is from 53.04 to 58.0 GHz. The PLL is designed and fabricated in 0.18-$mu{hbox{m}}$ CMOS technology. The measured phase noises at 1- and 10-MHz offset from the carrier are $-$ 85.2 and $-{hbox{90.9 dBc}}/{hbox{Hz}}$, respectively. The reference spur level of $-{hbox{40.16 dBc}}$ is measured. The dc power dissipation of the fabricated PLL is 35.7 mW under a 1.8-V supply. It can be seen that the advantages of lower power dissipation and similar phase noise can be achieved in the proposed PLL structure. It is suitable for low-power and high-performance $V$-band applications.      

A Digital Intensive Fractional-N PLL and All-Digital Self-Calibration Schemes

A digital intensive PLL featuring a digital filter in parallel with an analog feed-forward path and a digital controlled oscillator (DCO) is presented. Digital loop filter replaces analog passive filter to reduce chip area and associated gate-leakage in advanced process. It also allows the PLL loop gain and DCO gain to be digitally calibrated to within 100 ppm within 50 $mu{hbox{s}}$. Such fine frequency resolution enables the PLL to accurately compensate for the loop parameter variation due to process, voltage and temperature (PVT). The analog feed-forward path is insensitive to quantization error of fractional-N divider and DCO nonlinearity. Direct modulating the DCO frequency and phase through the analog feed-forward path, and compensating the modulating signal digitally for the DCO gain variation are demonstrated. At 3.6 GHz all fractional spurs are under $-$ 75 dBc. The phase noise at 400 kHz and 3 MHz are $-$115.6 dBc/Hz and $-$134.9 dBc/Hz, respectively. The chip is fabricated in a 0.13 $mu$ m CMOS process, and occupies an active area of 0.85 ${hbox{mm}}^{2}$ and draws 40 mA from a 1.5 V supply including all auxiliary circuitry.      

A 0.13 $mu$ m CMOS Quad-Band GSM/GPRS/EDGE RF Transceiver Using a Low-Noise Fractional-N Frequency Synthesizer and Direct-Conversion Architecture

This paper presents a single-chip CMOS quad-band (850/900/1800/1900 MHz) RF transceiver for GSM/GPRS/EDGE applications which adopts a direct-conversion receiver, a direct-conversion transmitter and a fractional-N frequency synthesizer with a built-in DCXO. In the GSM mode, the transmitter delivers 4 dBm of output power with 1$^{circ}$ RMS phase error and the measured phase noise is ${-}$164.5 dBc/Hz at 20 MHz offset from a 914.8$~$MHz carrier. In the EDGE mode, the TX RMS EVM is 2.4% with a 0.5 $~$dB gain step for the overall 36 dB dynamic range. The RX NF and IIP3 are 2.7 dB/ ${-}$12 dBm for the low bands (850/900 MHz) and 3 dB/${-}$ 11 dBm for the high bands (1800/1900 MHz). This transceiver is implemented in 0.13 $mu$m CMOS technology and occupies 10.5 mm$^{2}$ . The device consumes 118 mA and 84 mA in TX and RX modes from 2.8 V, respectively and is housed in a 5$,times,$ 5 mm$^{2}$ 40-pin QFN package.      

A Phase-Locked Loop With Self-Calibrated Charge Pumps in 3- $muhbox{m}$ LTPS-TFT Technology

A phase-locked loop (PLL) with self-calibrated charge pumps (CPs) has been fabricated in a 3- $muhbox{m}$ low-temperature polysilicon thin-film transistor (LTPS-TFT) technology. A voltage scaler and self-calibrated CPs are used to reduce the static phase error, reference spur, and jitter of an LTPS-TFT PLL. This PLL operates from 5.6 to 10.5 MHz at a supply of 8.4 V. Its area is 18.9 $hbox{mm}^{2}$, and it consumes 7.81 mW at 10.5 MHz. The measured static phase error without and with calibration is 80 and 6.56 ns, respectively, at 10.5 MHz. The measured peak-to-peak jitter without and with calibration is 3.573 and 2.834 ns, respectively. The measured reference spur is $-$26.04 and $-$ 30.2 dBc without and with calibration, respectively. The measured maximal locked time is 1.75 ms.      

A Sub-100 $mu{rm W}$ Ku-Band RTD VCO for Extremely Low Power Applications

This letter presents the microwave performance of a sub-100 $mu{rm W}$ Ku-band differential-mode resonant tunneling diode (RTD)-based voltage controlled oscillator (VCO) with an extremely low power consumption of 87 $mu{rm W}$ using an InP-based RTD/HBT MMIC technology. In order to achieve the extremely low-power Ku-band RTD VCO, the device size of RTD is scaled down to $0.6times 0.6 mu{rm m}^{2}$. The obtained dc power consumption of 87 $mu{rm W}$ is found to be only 1/18 of the conventional-type MMIC VCOs reported in the Ku-band. The fabricated RTD VCO has a phase noise of $-$100.3 dBc/Hz at 1 MHz offset frequency and a tuning range of 140 MHz with the figure-of-merit (FOM) of $-$194.3 dBc/Hz.      

2 MHz AO $Q$ -switched ${rm TEM}_{00}$ Grazing Incidence Laser With 3 at.% Neodymium Doped Nd:YVO$_{4}$

We present a detailed experimental and theoretical study of the ultrahigh repetition rate AO $Q$ -switched ${rm TEM}_{00}$ grazing incidence laser. Up to 2.1 MHz $Q$-switching with ${rm TEM}_{00}$ output of 8.6 W and 2.2 MHz $Q$ -switching with multimode output of 10 W were achieved by using an acousto-optics $Q$ -switched grazing-incidence laser with optimum grazing-incidence angle and cavity configuration. The crystal was 3 at.% neodymium doped Nd:YVO$_{4}$ slab. The pulse duration at 2 MHz repetition rate was about 31 ns. The instabilities of pulse energy at 2 MHz repetition rate were less than ${pm}6.7hbox{%}$ with ${rm TEM}_{00}$ operation and ${pm}3.3hbox{%}$ with multimode operation respectively. The modeling of high repetition rate $Q$-switched operation is presented based on the rate equation, and with the solution of the modeling, higher pump power, smaller section area of laser mode, and larger stimulated emission cross section of the gain medium are beneficial to the $Q$-switched operation with ultrahigh repetition rate, which is in consistent with the experimental results.      

A Wideband PLL-Based G/FSK Transmitter in 0.18 $mu$m CMOS

A wideband phase-locked loop (PLL)-based G/FSK transmitter (TX) architecture is presented in this paper. In the proposed TX, the G/FSK data is applied outside the loop; hence, the data rate is not constrained by the PLL bandwidth. In addition, the PLL remains locked all the time, preventing the carrier frequency from drifting. In this architecture, the G/FSK modulation signal is generated from a proposed Sigma-Delta modulated Phase Rotator $(SigmaDelta{hbox{-PR}})$. By properly combining the multi-phase signals from the PLL output, the $SigmaDelta{hbox{-PR}}$ effectively operates as a fractional frequency divider, which can synthesize modulation signals with fine-resolution frequencies. The proposed $SigmaDelta{hbox{-PR}}$ adopts the input signal as the phase transition trigger, facilitating a glitch-free operation. The impact of the $SigmaDelta{hbox{-PR}}$ on the TX output noise is also analyzed in this paper. The proposed TX with the $SigmaDelta{hbox{-PR}}$ is digitally programmable and can generate various G/FSK signals for different applications. Fabricated in a 0.18 $muhbox{m}$ CMOS technology, the proposed TX draws 6.3 mA from a 1.4 V supply, and delivers an output power of $-$11 dBm. With a maximum data rate of 6 Mb/s, the TX achieves an energy efficiency of 1.5 nJ/bit.      

A 5-GHz CMOS Frequency Synthesizer With an Injection-Locked Frequency Divider and Differential Switched Capacitors

A phase-locked loop (PLL)-based frequency synthesizer at 5 GHz is designed and fabricated in 0.18-${rm mu}hbox{m}$ CMOS technology. The power consumption of the synthesizer is significantly reduced by using an injection-locked frequency divider (ILFD) as the first frequency divider in the PLL feedback loop. The synthesizer chip consumes 18 mW of power, of which only 3.93 mW is consumed by the voltage-controlled oscillator (VCO) and the ILFD at 1.8-V supply voltage. The VCO has the phase noise of $-$ 104 dBc/Hz at 1-MHz offset and an output tuning range of 740 MHz. The chip size is 1.1 mm $times$ 0.95 mm.      

An FIR-Embedded Noise Filtering Method for $Delta Sigma$ Fractional-N PLL Clock Generators

This paper describes a noise filtering method for $Delta Sigma$ fractional- $N$ PLL clock generators to reduce out-of-band phase noise and improve short-term jitter performance. Use of a low-cost ring VCO mandates a wideband PLL design and complicates filtering out high-frequency quantization noise from the $Delta Sigma$ modulator. A hybrid finite impulse response (FIR) filtering technique based on a semidigital approach enables low-OSR $Delta Sigma$ modulation with robust quantization noise reduction despite circuit mismatch and nonlinearity. A prototype 1-GHz $Delta Sigma$ fractional-$N$ PLL is implemented in 0.18 $muhbox{m}$ CMOS. Experimental results show that the proposed semidigital method effectively suppresses the out-of-band quantization noise, resulting in nearly 30% reduction in short-term jitter.      

A Hybrid Spur Compensation Technique for Finite-Modulo Fractional-N Phase-Locked Loops

A finite-modulo fractional-$N$ PLL utilizing a low-bit high-order $DeltaSigma$ modulator is presented. A 4-bit fourth-order $DeltaSigma$ modulator not only performs non-dithered 16-modulo fractional-$N$ operation but also offers less spur generation with negligible quantization noise. Further spur reduction is achieved by charge compensation in the voltage domain and phase interpolation in the time domain, which significantly relaxes the dynamic range requirement of the charge pump compensation current. A 1.8–2.6 GHz fractional-$N$ PLL is implemented in 0.18 $mu{hbox {m}}$ CMOS. By employing high-order deterministic $DeltaSigma$ modulation and hybrid spur compensation, the spur level of less than $-$55 dBc is achieved when the ratio of the bandwidth to minimum frequency resolution is set to 1/4. The prototype PLL consumes 35.3 mW in which only 2.7 mW is consumed by the digital modulator and compensation circuits.      

A 22–29-GHz UWB Pulse-Radar Receiver Front-End in 0.18-$mu{hbox{m}}$ CMOS

The design of a CMOS 22–29-GHz pulse-radar receiver (RX) front-end for ultra-wideband automotive radar sensors is presented. The chip includes a low-noise amplifier, in-phase/quadrature mixers, a quadrature voltage-controlled oscillator (QVCO), pulse formers, and baseband variable-gain amplifiers. Fabricated in a 0.18-$mu{hbox{m}}$ CMOS process, the RX front-end chip occupies a die area of 3 ${hbox{mm}}^{2}$. On-wafer measurements show a conversion gain of 35–38.1 dB, a noise figure of 5.5–7.4 dB, and an input return loss less than $-$14.5 dB in the 22–29-GHz automotive radar band. The phase noise of the constituent QVCO is $-$107 dBc/Hz at 1-MHz offset from a center frequency of 26.5 GHz. The total dc power dissipation of the RX including output buffers is 131 mW.      

A 4.39–5.26 GHz LC-Tank CMOS Voltage-Controlled Oscillator With Small VCO-Gain Variation

A wide band CMOS LC-tank voltage controlled oscillator (VCO) with small VCO gain $(K_{VCO})$ variation was developed. For small $K_{VCO}$ variation, serial capacitor bank was added to the LC-tank with parallel capacitor array. Implemented in a 0.18 $mu{rm m}$ CMOS RF technology, the proposed VCO can be tuned from 4.39 GHz to 5.26 GHz with the VCO gain variation less than 9.56%. While consuming 3.5 mA from a 1.8 V supply, the VCO has $-$ 113.65 dBc/Hz phase noise at 1 MHz offset from the carrier.      

A Low Phase-Noise QVCO With Integrated Back-Gate Coupling and Source Resistive Degeneration Technique

A 0.18 $mu$ m CMOS quadrature voltage-controlled oscillator with an extremely-low phase noise is presented. The excellent phase noise performance is accomplished by integration of the back-gate quadrature phase coupling and source resistive degeneration techniques into a complementary oscillator topology. The measured phase noise is as low as ${-}133$ dBc/Hz at 1 MHz offset from 3.01 GHz. The output phase imbalance is less than 1$^{circ}$ . The output power is $-1.25{pm} 0.5$ dBm and harmonic suppression is greater than 30.8 dBc. The oscillator core consumes 5.38 mA from a 1.5 V power supply. This QVCO achieves the highest figure-of-merit of ${-}193.5$ dBc/Hz.      

$hbox{TiN/ZrO}_{2}$/Ti/Al Metal–Insulator–Metal Capacitors With Subnanometer CET Using ALD-Deposited $hbox{ZrO}_{2}$ for DRAM Applications

We provide the first report of the structural and electrical properties of $hbox{TiN/ZrO}_{2}$/Ti/Al metal–insulator–metal capacitor structures, where the $hbox{ZrO}_{2}$ thin film (7–8 nm) is deposited by ALD using the new zirconium precursor ZrD-04, also known as Bis(methylcyclopentadienyl) methoxymethyl. Measured capacitance–voltage ($C$– $V$) and current–voltage ( $I$–$V$) characteristics are reported for premetallization rapid thermal annealing (RTP) in $hbox{N}_{2}$ for 60 s at 400 $^{circ}hbox{C}$, 500 $^{circ}hbox{C}$, or 600 $^{ circ}hbox{C}$. For the RTP at 400 $^{circ}hbox{C}$ , we find very low leakage current densities on the order of nanoamperes per square centimeter at a gate voltage of 1 V and low capacitance equivalent thickness values of $sim$ 0.9 nm at a gate voltage of 0 V. The dielectric constant of $ hbox{ZrO}_{2}$ is 31 $pm$ 2 after RTP treatment at 400 $^{circ}hbox{C}$.      

A Low-Noise Wide-BW 3.6-GHz Digital $DeltaSigma$ Fractional-N Frequency Synthesizer With a Noise-Shaping Time-to-Digital Converter and Quantization Noise Cancellation

A 3.6-GHz digital fractional-N frequency synthesizer achieving low noise and 500-kHz bandwidth is presented. This architecture uses a gated-ring-oscillator time-to-digital converter (TDC) with 6-ps raw resolution and first-order shaping of its quantization noise along with digital quantization noise cancellation to achieve integrated phase noise of less than 300 fs (1 kHz to 40 MHz). The synthesizer includes two 10-bit 50-MHz passive digital-to-analog converters for digital control of the oscillator and an asynchronous frequency divider that avoids divide-value delay variation at its output. Implemented in a 0.13-$mu$m CMOS process, the prototype occupies 0.95-mm$^{2}$ active area and dissipates 39 mW for the core parts with another 8 mW for the oscillator output buffer. Measured phase noise at 3.67 GHz carrier frequency is $-$108 and $-$150 dBc/Hz at 400 kHz and 20 MHz offset, respectively.      

$S$ - and $C$ -Band Ultra-Compact Phase Shifters Based on All-Pass Networks

Ultra-compact phase shifters are presented. The proposed phase-shifting circuits utilize the lumped element all-pass networks. The transition frequency of the all-pass network, which determines the size of the circuit, is set to be much higher than the operating frequency. This results in a significantly small chip size of the phase shifter. To verify this methodology, 5-bit phase shifters have been fabricated in the $S$ - and $C$ -band. The $S$ -band phase shifter, with a chip size of 1.87 mm $,times,$0.87 mm (1.63 mm $^{2}$), has achieved an insertion loss of ${hbox{6.1 dB}} pm {hbox{0.6 dB}}$ and rms phase-shift error of less than 2.8$^{circ}$ in 10% bandwidth. The $C$ -band phase shifter, with a chip size of 1.72 mm $,times,$0.81 mm (1.37 mm $^{2}$), has demonstrated an insertion loss of 5.7 dB $pm$ 0.8 dB and rms phase-shift error of less than 2.3 $^{circ}$ in 10% bandwidth.      

A 0.18-$muhbox{m}$ CMOS GFSK Analog Front End Using a Bessel-Based Quadrature Discriminator With On-Chip Automatic Tuning

A fully integrated 2-MHz Gaussian frequency-shift keying (GFSK) analog front end for low-IF receivers is presented. The analog GFSK demodulation uses a Bessel-based quadrature discriminator and a differentiator-based data decision circuit, eliminating the need for analog–digital converters while enabling high sensitivity and large frequency offset tolerance. The analog front end consists of a fifth-order Butterworth low-pass prefilter, a seven-stage limiter, a quadrature discriminator with a fourth-order Bessel phase-shift network, a fourth-order Butterworth low-pass postfilter, and a differentiator-based data decision circuit. The prefilter, Bessel phase shifter, postfilter, and differentiator are built using identical $Gm{-}C$ cells and tuned across process variations with a single master–slave phase-locked loop. The GFSK analog front end is implemented in a 1.8-V 0.18-${rm mu}hbox{m}$ CMOS process, recovering 1-Mb/s input data from a 2-MHz GFSK signal with maximum frequency deviation of $pm$160-kHz, frequency offset tolerance from $-$ 38% to $+$ 47%, and input sensitivity of $-$53 dBm and consuming 7 mA of current.      

17 GHz RF Front-Ends for Low-Power Wireless Sensor Networks

A 17 GHz low-power radio transceiver front-end implemented in a 0.25 $mu{hbox {m}}$ SiGe:C BiCMOS technology is described. Operating at data rates up to 10 Mbit/s with a reduced transceiver turn-on time of 2 $mu{hbox {s}}$, gives an overall energy consumption of 1.75 nJ/bit for the receiver and 1.6 nJ/bit for the transmitter. The measured conversion gain of the receiver chain is 25–30 dB into a 50 $Omega$ load at 10 MHz IF, and noise figure is 12 $pm$0.5 dB across the band from 10 to 200 MHz. The 1-dB compression point at the receiver input is $-$37 dBm and ${hbox{IIP}}_{3}$ is $-$25 dBm. The maximum saturated output power from the on-chip transmit amplifier is $-$1.4 dBm. Power consumption is 17.5 mW in receiver mode, and 16 mW in transmit mode, both operating from a 2.5 V supply. In standby, the transceiver supply current is less than 1 $mu{hbox {A}}$.      

A $Q$ -Band Four-Element Phased-Array Front-End Receiver With Integrated Wilkinson Power Combiners in 0.18-$mu{{hbox{m}}}$ SiGe BiCMOS Technology

A four-element phased-array front-end receiver based on 4-bit RF phase shifters is demonstrated in a standard 0.18- $mu{{hbox{m}}}$ SiGe BiCMOS technology for $Q$-band (30–50 GHz) satellite communications and radar applications. The phased-array receiver uses a corporate-feed approach with on-chip Wilkinson power combiners, and shows a power gain of 10.4 dB with an ${rm IIP}_{3}$ of $-$13.8 dBm per element at 38.5 GHz and a 3-dB gain bandwidth of 32.8–44 GHz. The rms gain and phase errors are $leq$1.2 dB and $leq {hbox{8.7}}^{circ}$ for all 4-bit phase states at 30–50 GHz. The beamformer also results in $leq$ 0.4 dB of rms gain mismatch and $leq {hbox{2}}^{circ}$ of rms phase mismatch between the four channels. The channel-to-channel isolation is better than $-$35 dB at 30–50 GHz. The chip consumes 118 mA from a 5-V supply voltage and overall chip size is ${hbox{1.4}}times {hbox{1.7}} {{hbox{mm}}}^{2}$ including all pads and CMOS control electronics.