Low-power/low-voltage RF microsystems for wireless sensors networks

This paper presents radio-frequency (RF) microsystems (MSTs) composed by low-power devices for use in wireless sensors networks (WSNs). The RF CMOS transceiver is the main electronic system and its power consumption is a critical issue. Two RF CMOS transceivers with low-power and low-voltage supply were fabricated to operate in the 2.4 and 5.7 GHz ISM bands. The measurements made in the RF CMOS transceiver at 2.4 GHz, which showed a sensitivity of −60 dBm with a power consumption of 6.3 mW from 1.8 V supply. The measurements also showed that the transmitter delivers an output power of 0 dBm with a power consumption of 11.2 mW. The RF CMOS transceiver at 5.7 GHz has a total power consumption of 23 mW. The target application of these RF CMOS transceivers is for MSTs integration and for use as low-power nodes in WSNs to work during large periods of time without human operation, management and maintenance. These RF CMOS transceivers are also suitable for integration in thermoelectric energy scavenging MSTs.     

Design of Ultra-Low-Voltage RF Frontends With Complementary Current-Reused Architectures

In this paper, ultra-low-voltage circuit techniques are presented for CMOS RF frontends. By employing a complementary current-reused architecture, the RF building blocks including a low-noise amplifier (LNA) and a single-balanced down-conversion mixer can operate at a reduced supply voltage with microwatt power consumption while maintaining reasonable circuit performance at multigigahertz frequencies. Based on the MOSFET model in moderate and weak inversion, theoretical analysis and design considerations of the proposed circuit techniques are described in detail. Using a standard 0.18-mum CMOS process, prototype frontend circuits are implemented at the 5-GHz frequency band for demonstration. From the measurement results, the fully integrated LNA exhibits a gain of 9.2 dB and a noise figure of 4.5 dB at 5 GHz, while the mixer has a conversion gain of 3.2 dB and an IIP₃ of -8 dBm. Operated at a supply voltage of 0.6 V, the power consumptions of the LNA and the mixer are 900 and 792 muW, respectively.     

26.5–30-GHz Resistive Mixer in 90-nm VLSI SOI CMOS Technology With High Linearity for WLAN

A resistive mixer with high linearity for wireless local area networks is presented in this paper. The fully integrated circuit is fabricated with a 90-nm very large scale integration silicon-on-insulator (SOI) CMOS technology and has a very compact size of 0.38 mm$, times,$0.32 mm. Design guidelines are given to optimize the circuit performance. Analytical calculations and simulations with an SOI large-signal Berkeley simulation model show good agreement with measurements. At an RF of 27 GHz, an IF of 2.5 GHz and zero dc power consumption, a conversion loss of 9.7 dB, a single-sideband noise figure of 11.4 dB, and a high third-order intercept point at the input of 20 dBm are measured at a local-oscillator (LO) power of 10 dBm. At lower LO power of 0-dBm LO power, the loss is 10.3 dB. To the knowledge of the author, the circuit has by far the highest operation frequency reported to date for a resistive CMOS mixer. Furthermore, it provides the highest linearity for a CMOS mixer operating at such high frequencies.     

Design and analysis of an ultrawide-band distributed CMOS mixer

This paper presents the design and analysis of a novel distributed CMOS mixer for ultrawide-band (UWB) receivers. To achieve the UWB RF frequency range required for the UWB communications, the proposed mixer incorporates artificial inductance-capacitance (LC) delay lines in radio frequency (RF), local oscillator (LO), and intermediate frequency signal paths, and single-balanced mixer cells that are distributed along these LC circuits. Closed-form analytical model for the conversion gain of the mixer is presented. Furthermore, a comprehensive noise analysis of the proposed distributed mixer is carried out, which includes calculation of the mixer noise figure (NF) and derivation of the optimum number of stages, n, minimizing the NF. The designed mixer is capable of covering the RF and LO frequencies over a wide range of frequencies from 3.1-8.72 GHz. A two-stage distributed mixer has been fabricated in a 0.18-/spl mu/m CMOS process. Experiments show a conversion gain of more than 2.5 dB for the entire range of the frequencies. The dc power consumption is 10.4 mW.     

A New Lossy Substrate Model for Accurate RF CMOS Noise Extraction and Simulation With Frequency and Bias Dependence

A lossy substrate model is developed to accurately simulate the measured RF noise of 80-nm super-100-GHz f_T n-MOSFETs. A substrate RLC network built in the model plays a key role responsible for the nonlinear frequency response of noise in 1-18-GHz regime, which did not follow the typical thermal noise theory. Good match with the measured S-parameters, Y-parameters, and noise parameters before deembedding proves the lossy substrate model. The intrinsic RF noise can be extracted easily and precisely by the lossy substrate deembedding using circuit simulation. The accuracy has been justified by good agreement in terms of I_d,g_m, Y-parameters, and f _T under a wide range of bias conditions and operating frequencies. Both channel thermal noise and resistance induced excess noises have been implemented in simulation. A white noise gamma factor extracted to be higher than 2/3 accounts for the velocity saturation and channel length modulation effects. The extracted intrinsic NF_min as low as 0.6-0.7 dB at 10 GHz indicates the advantages of super-100 GHz f_T offered by the sub-100-nm multifinger n-MOSFETs. The frequency dependence of noise resistance R_n suggests the bulk RC coupling induced excess channel thermal noise apparent in 1-10-GHz regime. The study provides useful guideline for low noise and low power design by using sub-100-nm RF CMOS technology     

Modified derivative superposition method for linearizing FET low-noise amplifiers

Intermodulation distortion in field-effect transistors (FETs) at RF frequencies is analyzed using the Volterra-series analysis. The degrading effect of the circuit reactances on the maximum IIP₃ in the conventional derivative-superposition (DS) method is explained. The noise performance of this method is also analyzed and the effect of the subthreshold biasing of one of the FETs on the noise figure (NF) is shown. A modified DS method is proposed to increase the maximum IIP₃ at RF. It was used in a 0.25-mum Si CMOS low-noise amplifier (LNA) designed for cellular code-division multiple-access receivers. The LNA achieved +22-dBm IIP₃ with 15.5-dB gain, 1.65-dB NF, and 9.3 mA@2.6-V power consumption     

A 2.4-GHz 24-dBm SOI CMOS Power Amplifier With Fully Integrated Reconfigurable Output Matching Network

In this paper, the potential of load adaptation for enhanced backoff efficiency in RF power amplifiers (PAs) has been investigated through a 0.13-mum silicon-on-insulator (SOI) CMOS fabrication technology. The RF power performance of the adopted SOI CMOS process has been preliminarily characterized by on-wafer load-pull measurements on a custom unit power transistor. A 2.4-GHz 24-dBm 2-V SOI CMOS PA with fully integrated reconfigurable output matching network has then been designed and experimentally characterized. A significant efficiency improvement of up to 34% has been achieved through load adaptation, peak efficiency being as high as 65%. Linear operation has also been demonstrated under two-tone excitation, as a 16-dBm output power has been attained while complying with a - 40-dBc third-order intermodulation distortion specification.     

A 0.8-dB NF ESD-Protected 9-mW CMOS LNA operating at 1.23 GHz [forGPS receiver]

In recent years, much research has been carried out on the possibility of using pure CMOS, rather than bipolar or BiCMOS technologies, for radio-frequency (RF) applications. An example of such an application is the Global Positioning System (GPS). One of the important bottlenecks to make the transition to pure CMOS is the immunity of the circuits against electrostatic discharge (ESD). This paper shows that it is possible to design a low-noise amplifier (LNA) with very good RF performance and sufficient ESD immunity by carefully co-designing both the LNA and ESD protection. This is demonstrated with a 0.8-dB noise figure LNA with an ESD protection of -1.4-0.6 kV human body model (HBM) with a power consumption of 9 mW. The circuit was designed as a standalone LNA for a 1.2276-GHz GPS receiver. It is implemented in a standard 0.25-μm 4M1P CMOS process     

The impact of scaling down to deep submicron on CMOS RF circuits

Recent papers reporting CMOS RF building blocks have aroused great expectations for RF receivers using deep-submicron technologies. This paper examines the trend in CMOS scaling, in order to establish the required current levels and achievable performance for different feature sizes, if robust, easily manufacturable designs are to be implemented for cellular applications. The boundary conditions (system-level constraints) for such designs, in terms of the number of trimmed and untrimmed external components and the roles they play in relaxing active circuit requirements, are emphasized throughout to make comparison of active RF circuits meaningful. At 1 GHz, 0.25-μm CMOS appears to be the threshold for robust, low-NF RF front ends with current consumption competitive with today's BJT implementations     

0.15-μm RF CMOS technology compatible with logic CMOS forlow-voltage operation

Radio Frequency (RF) CMOS is expected to replace bipolar and GaAs MESFETs in RF front-end ICs for mobile telecommunications devices in the near future. In order for the RF CMOS to be popularly used in this application, compatibility of its process for high-speed logic CMOS and low supply voltage operation are important for low fabrication cost and low power consumption. In this paper, a 0.15-μm RF CMOS technology compatible with logic CMOS for low-voltage operation is described. Because the fabrication process is the same as the high-speed logic CMOS, manufacturability of this technology is excellent. Some of the passive elements can be integrated without changing the process and others can be integrated with the addition of a few optional processes. Mixed RF and logic CMOS devices in a one-chip LSI can be realized with relatively low cost. Excellent high-frequency characteristics of small geometry silicon MOSFETs with low-power supply voltage are demonstrated. Cutoff frequency of 42 GHz of n-MOSFETs, which is almost the same level at that of general high-performance silicon bipolar transistors, was obtained. N-MOSFET's maintained enough high cutoff frequency of 32 GHz even at extremely low supply voltage of 0.5 V. Moreover, it was confirmed that degradation of minimum noise figure for deep submicron MOSFETs with 0.5 V operation is sufficiently small compared with 2.0 V operation. These excellent high-frequency characteristics of small geometry silicon MOSFETs under low-voltage operation are suitable for mobile telecommunications applications     

SiGe Radio Frequency ICs for Low-Power Portable Communication

The range and impact of SiGe bipolar and BiCMOS technologies on wireless transceivers for portable telephony and data communications are surveyed. SiGe technology enables transceiver designs that compare favorably with competing technologies such as RF CMOS or III-Vs, with advantages in design cycle time and performance versus cost. As wireless devices continue to increase in complexity using conventional battery technology as the power source, the desire to reduce current consumption in future transceivers continues to favor SiGe technology. Examples are drawn from contemporary wireless communications ICs. The performance of on-chip passive components in silicon technologies are also reviewed in this paper. Greater understanding of the limitations of passive devices coupled with improved models for their performance are leading to circuits offering wider RF dynamic range at ever higher operating frequencies. The innovations in on-chip passive design and construction currently being pioneered in mixed-signal SiGe technologies are enabling circuits operating deep into millimeter-wave frequency bands (i.e., well above 30 GHz). In addition, sophisticated on-chip magnetic components combined with deep submicrometer SiGe active devices in a transceiver front end are envisioned that enable single-volt SiGe circuits, with even lower current consumption than is achievable today. Relevant examples from the recent literature are presented.     

Thick Metal CMOS Technology on High Resistivity Substrate and Its Application to Monolithic L-Band CMOS LNAs

Thick metal 0.8 µm CMOS technology on high resistivity substrate (RF CMOS technology) is demonstrated for the L-band RF IC applications, and we successfully implemented it to the monolithic 900 MHz and 1.9 GHz CMOS LNAs for the first time. To enhance the performance of the RF circuits, MOSFET layout was optimized for high frequency operation and inductor quality was improved by modifying the technology. The fabricated 1.9 GHz LNA shows a gain of 15.2 dB and a NF of 2.8 dB at DC consumption current of 15 mA that is an excellent noise performance compared with the off-chip matched 1.9 GHz CMOS LNAs. The 900 MHz LNA shows a high gain of 19 dB and NF of 3.2 dB despite of the performance degradation due to the integration of a 26 nH inductor for input match. The proposed RF CMOS technology is a compatible process for analog CMOS ICs, and the monolithic LNAs employing the technology show a good and uniform RF performance in a five inch wafer.     

Design and performance analysis of double-gate MOSFET over single-gate MOSFET for RF switch

In this paper, we have designed a double-gate MOSFET and compared its performance parameters with the single-gate MOSFET as RF CMOS switch, particularly the double-pole four-throw (DP4T) switch, for the wireless telecommunication systems. A double-gate radio-frequency complementary metal-oxide-semiconductor (DG RF CMOS) switch operating at the frequency of microwave range is investigated. This RF switch is capable to select the data streams from antennas for both the transmitting and receiving processes. We emphasize on the basics of the circuit elements (such as drain current, threshold voltage, resonant frequency, resistances at switch ON condition, capacitances, and switching speed) required for the integrated circuit of the radio frequency sub-system of the DG RF CMOS switch and the role of these basic circuit elements are also discussed. These properties presented in the switches due to the double-gate MOSFET and single-gate MOSFET have been discussed.     

A 1.5-V full-swing BiCMOS logic circuit

A BiCMOS logic circuit applicable to sub-2-V digital circuits has been developed. A transiently saturated full-swing BiCMOS (TS-FS-BiCMOS) logic circuit operates twice as fast as CMOS at 1.5-V supply. A newly developed transient-saturation technique, with which bipolar transistors saturate only during switching periods, is the key to sub-2-V operation because a high-speed full-swing operation is achieved to remove the voltage loss due to the base-emitter turn-on voltage. Both small load dependence and small fan-in dependence of gate delay time are attained with this technique. A two-input gate fabricated with 0.3-μm BiCMOS technology verifies the performance advantage of TS-FS-BiCMOS over other BiCMOS circuits and CMOS at sub 2-V supply     

Design and Analysis for a 60-GHz Low-Noise Amplifier With RF ESD Protection

An RF electrostatic discharge (ESD) protection for millimeter-wave (MMW) regime applied to a 60-GHz low-noise amplifier (LNA) in mixed-signal and RF purpose 0.13-$mu{hbox{m}}$ CMOS technology is demonstrated in this paper. The measured results show that this chip achieves a small signal gain of 20.4 dB and a noise figure (NF) of 8.7 dB at 60 GHz with 65-mW dc power consumption. Without ESD protection, the LNA exhibits a gain of 20.2 dB and an NF of 7.2 dB at 60 GHz. This ESD protection using an impedance isolation method to minimize the RF performance degradation sustains 6.5-kV voltage level of the human body model on the diode and 1.5 kV on the core circuit, which is much higher than that without ESD protection ( $≪$350 V). To our knowledge, this is the first CMOS LNA with RF ESD protection in the MMW regime and has the highest operation frequency reported to date.      

Linear and nonlinear characteristics of the silicon CMOS monolithic50-Ω microwave and RF control element

Radio-frequency (RF) control elements using silicon CMOS technology are investigated as an alternative to traditional PIN diode and GaAs MESFET control devices. Silicon CMOS RF control elements are attractive because of their potential in all-silicon monolithic CMOS solutions for completely integrated baseband and RF functions in low-cost wireless systems. Results of the study show that silicon CMOS switches can be designed to rival the insertion loss and isolation of gallium arsenide switches at low frequencies. Data are presented that show less than 1 dB insertion loss and isolation of greater than 50 dB at low frequencies for a variety of silicon CMOS fabrication technologies. A model for a distortion intercept point in MOS switches is presented and validated with experimental measurements     

Analysis of leakage currents and impact on off-state powerconsumption for CMOS technology in the 100-nm regime

Off-state leakage currents have been investigated for sub-100 nm CMOS technology. The two leakage mechanisms investigated in this work include conventional off-state leakage due to short channel effects and gate leakage through ultrathin gate oxides. The conventional off-state leakage due to short channel effects exhibited the similar characteristics as previously published; however, gate leakage introduces two significant consequences with respect to off-state power consumption: (1) an increase in the number of transistors contributing to the total off-state power consumption of the chip and (2) an increase in the conventional off-state current due to gate leakage near the drain region of the device. Using experimentally measured data, it is estimated that gate leakage does not exceed the off-state specifications of the National Technology Roadmap for Semiconductors for gate oxides as thin as 1.4 to 1.5 nm for high performance CMOS. Low power and memory applications may be limited to an oxide thickness of 1.8 to 2.0 nm in order to minimize the off-state power consumption and maintain an acceptable level of charge retention. The analysis in this work suggests that reliability will probably limit silicon oxide scaling for high performance applications whereas gate leakage will limit gate oxide scaling for low power and memory applications     

Distortion in RF CMOS short-channel low-noise amplifiers

An approach to estimate the distortion in CMOS short-channel (e.g. 0.18-/spl mu/m gate length) RF low-noise amplifiers (LNAs), based on Volterra's series, is presented. Compact and accurate frequency-dependent closed-form expressions describing the effects of the different transistor parameters on harmonic distortion are derived. For the first time, the second-order distortion (HD2), in CMOS short-channel based LNAs, is studied. This is crucial for systems such as homodyne receivers. Equations describing third-order intermodulation distortion in RF LNAs are reported. The analytical analysis is verified through simulations and measured results of an 0.18-/spl mu/m CMOS 5.8-GHz folded-cascode LNA prototype chip geared toward sub-1-V operation. It is shown that the distortion is independent of the gate-source capacitance C/sub gs/ of the MOS transistors, allowing an extra degree of freedom in the design of LNA circuits. Distortion-aware design guidelines for RF CMOS LNAs are provided throughout the paper.     

RF集成电感的设计与寄生效应分析

分析了体硅 CMOS RF集成电路中电感的寄生效应 ,以及版图参数对电感品质因数 Q的影响 ,并通过Matlab程序模拟了在衬底电阻、金属条厚度、氧化层厚度改变时电感品质因数的变化 ,分析了不同应用频率时版图参数在寄生效应中所起的作用 ,得出了几条实用的设计原则并进行了实验验证 ,实验结果与模拟值符合得很好 ,表明此模拟方法与所得结论均可有效地用于指导射频 (RF)集成电路中集成电感的设计     

CMOS technology for MS/RF SoC

Accelerated scaling of CMOS technology has contributed to remove otherwise fundamental barriers preempting its widespread application to mixed-signal/radio-frequency (MS/RF) segments. Improvements in device speed, matching, and minimum noise figure are all consistent with fundamental scaling trends. Other figures-of-merit such as linearity and 1/f noise do not scale favorably but are not considered to be roadblocks when viewed from a circuit design perspective. Furthermore, interconnect architectural scaling trends in logic technology have facilitated improvements in passive-component performance metrics. These improvements compounded with innovations in circuit design have made CMOS technology the primary choice for cost driven MS/RF applications. This paper reviews active and passive elements of CMOS MS/RF system-on-chip (SoC) technology from a scaling perspective. The paper also discusses the implications that physical phenomena such as mechanical stress and gate leakage as well as gate patterning have on technology definition and characterization.