101 research outputs found

    A Novel High Linearity and Low Power Folded CMOS LNA for UWB Receivers

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    © 2017 World Scientific Publishing Company. Electronic version of an article published as Journal of Circuits, Systems and Computers, Vol. 27, No. 03, 1850047, https://doi.org/10.1142/S0218126618500470.This paper presents a high linearity and low power Low-Noise Amplifier (LNA) for Ultra-Wideband (UWB) receivers based on CHRT 0.18μm CMOS technology. In this work, the folded topology is adopted in order to reduce the supply voltage and power consumption. Moreover, a band-pass LC filter is embedded in the folded-cascode circuit to extend bandwidth. The transconductance nonlinearity has a great impact on the whole LNA linearity performance under a low supply voltage. A post-distortion (PD) technique employing an auxiliary transistor is applied in the transconductance stage to improve the linearity. The post-layout simulation results indicate that the proposed LNA achieves a maximum power gain of 12.8dB. The input and output reflection coefficients both are lower than -10.0dB over 2.5~11.5GHz. The input third-order intercept point (IIP3) is 5.6dBm at 8GHz and the noise figure (NF) is lower than 4.0dB. The LNA consumes 5.4mW power under a 1V supply voltage.Peer reviewe

    Ultra Wideband

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    Ultra wideband (UWB) has advanced and merged as a technology, and many more people are aware of the potential for this exciting technology. The current UWB field is changing rapidly with new techniques and ideas where several issues are involved in developing the systems. Among UWB system design, the UWB RF transceiver and UWB antenna are the key components. Recently, a considerable amount of researches has been devoted to the development of the UWB RF transceiver and antenna for its enabling high data transmission rates and low power consumption. Our book attempts to present current and emerging trends in-research and development of UWB systems as well as future expectations

    Introduction to the special issue on the 36th European Solid-State Circuits Conference (ESSCIRC)

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    The 22 papers in this special issue were originally presented at the 2010 European Solid-State Circuits Conference (ESSCIRC). The conference was jointly organized with the European Solid-State Device Research Conference and held September 14-16 in Seville, Spain. Papers cover the traditional ESSCIRC topics of analog circuits, digital circuits, data converters, sensors and imagers, and communications and RF circuits. Energy harvesting and biomedical circuits were also within ESSCIRC 2010 topics and are represented in this issue

    Design of a tunable multi-band differential LC VCO using 0.35 mu m SiGe BiCMOS technology for multi-standard wireless communication systems

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    In this paper, an integrated 2.2-5.7GHz multi-band differential LC VCO for multi-standard wireless communication systems was designed utilizing 0.35 mu m SiGe BiCMOS technology. The topology, which combines the switching inductors and capacitors together in the same circuit, is a novel approach for wideband VCOs. Based on the post-layout simulation results, the VCO can be tuned using a DC voltage of 0 to 3.3 V for 5 different frequency bands (2.27-2.51 GHz, 2.48-2.78 GHz, 3.22-3.53 GHz, 3.48-3.91 GHz and 4.528-5.7 GHz) with a maximum bandwidth of 1.36 GHz and a minimum bandwidth of 300 MHz. The designed and simulated VCO can generate a differential output power between 0.992 and -6.087 dBm with an average power consumption of 44.21 mW including the buffers. The average second and third harmonics level were obtained as -37.21 and -47.6 dBm, respectively. The phase noise between -110.45 and -122.5 dBc/Hz, that was simulated at 1 MHz offset, can be obtained through the frequency of interest. Additionally, the figure of merit (FOM), that includes all important parameters such as the phase noise, the power consumption and the ratio of the operating frequency to the offset frequency, is between -176.48 and -181.16 and comparable or better than the ones with the other current VCOs. The main advantage of this study in comparison with the other VCOs, is covering 5 frequency bands starting from 2.27 up to 5.76 GHz without FOM and area abandonment. Output power of the fundamental frequency changes between -6.087 and 0.992 dBm, depending on the bias conditions (operating bands). Based on the post-layout simulation results, the core VCO circuit draws a current between 2.4-6.3 mA and between 11.4 and 15.3 mA with the buffer circuit from 3.3 V supply. The circuit occupies an area of 1.477 mm(2) on Si substrate, including DC, digital and RF pads

    HIGH LINEARITY UNIVERSAL LNA DESIGNS FOR NEXT GENERATION WIRELESS APPLICATIONS

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    Design of the next generation (4G) systems is one of the most active and important area of research and development in wireless communications. The 2G and 3G technologies will still co-exist with the 4G for a certain period of time. Other applications such as wireless LAN (Local Area Network) and RFID are also widely used. As a result, there emerges a trend towards integrating multiple wireless functionalities into a single mobile device. Low noise amplifier (LNA), the most critical component of the receiver front-end, determines the sensitivity and noise figure of the receiver and is indispensable for the complete system. To satisfy the need for higher performance and diversity of wireless communication systems, three LNAs with different structures and techniques are proposed in the thesis based on the 4G applications. The first LNA is designed and optimized specifically for LTE applications, which could be easily added to the existing system to support different standards. In this cascode LNA, the nonlinearity coming from the common source (CS) and common gate (CG) stages are analyzed in detail, and a novel linear structure is proposed to enhance the linearity in a relatively wide bandwidth. The LNA has a bandwidth of 900MHz with the linearity of greater than 7.5dBm at the central frequency of 1.2GHz. Testing results show that the proposed structure effectively increases and maintains linearity of the LNA in a wide bandwidth. However, a broadband LNA that covers multiple frequency ranges appears more attractive due to system simplicity and low cost. The second design, a wideband LNA, is proposed to cover multiple wireless standards, such as LTE, RFID, GSM, and CDMA. A novel input-matching network is proposed to relax the tradeoff among noise figure and bandwidth. A high gain (>10dB) in a wide frequency range (1-3GHz) and a minimum NF of 2.5dB are achieved. The LNA consumes only 7mW on a 1.2V supply. The first and second LNAs are designed mainly for the LTE standard because it is the most widely used standard in the 4G communication systems. However, WiMAX, another 4G standard, is also being widely used in many applications. The third design targets on covering both the LTE and the WiMAX. An improved noise cancelling technique with gain enhancing structure is proposed in this design and the bandwidth is enlarged to 8GHz. In this frequency range, a maximum power gain of 14.5dB and a NF of 2.6-4.3dB are achieved. The core area of this LNA is 0.46x0.67mm2 and it consumes 17mW from a 1.2V supply. The three designs in the thesis work are proposed for the multi-standard applications based on the realization of the 4G technologies. The performance tradeoff among noise, linearity, and broadband impedance matching are explored and three new techniques are proposed for the tradeoff relaxation. The measurement results indicate the techniques effectively extend the bandwidth and suppress the increase of the NF and nonlinearity at high frequencies. The three proposed structures can be easily applied to the wideband and multi-standard LNA design

    Characterization of 28 nm FDSOI MOS and application to the design of a low-power 2.4 GHz LNA

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    IoT is expected to connect billions of devices all over world in the next years, and in a near future, it is expected to use LR-WPAN in a wide variety of applications. Not all the devices will require of high performance but will require of low power hungry systems since most of them will be powered with a battery. Conventional CMOS technologies cannot cover these needs even scaling it to very small regimes, which appear other problems. Hence, new technologies are emerging to cover the needs of this devices. One promising technology is the UTBB FDSOI, which achieves good performance with very good energy efficiency. This project characterizes this technology to obtain a set of parameters of interest for analog/RF design. Finally, with the help of a low-power design methodology (gm/Id approach), a design of an ULP ULV LNA is performed to check the suitability of this technology for IoT

    Analysis and design of low power CMOS ultra wideband receiver

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    This research concentrates on the design and analysis of low power ultra wideband receivers for Multiband Orthogonal Frequency Division Multiplexing systems. Low power design entails different performance tradeoffs, which are analyzed. Relationship among power consumption, achievable noise figure and linearity performance including distortion products (cross-modulation, inter-modulation and harmonic distortion) are derived. From these relationships, circuit design proceeds with allocation of gain among different sub circuit blocks for power optimum system. A power optimum RF receiver front-end for MB-OFDM based UWB systems is designed that covers all the MB-OFDM spectrum between 3.1 GHZ to 9.6 GHZ. The receiver consists of a low-noise amplifier, down-converter, channel select filter and programmable gain amplifier and occupies only 1mm 2 in 0.13um CMOS process. Receiver consumes 20 mA from a 1.2 V supply and has the measured gain of 69db, noise figure less than 6 dB and input IIP 3 of -6 dBm

    Advances in Integrated Circuit Design and Implementation for New Generation of Wireless Transceivers

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    User’s everyday outgrowing demand for high-data and high performance mobile devices pushes industry and researchers into more sophisticated systems to fulfill those expectations. Besides new modulation techniques and new system designs, significant improvement is required in the transceiver building blocks to handle higher data rates with reasonable power efficiency. In this research the challenges and solution to improve the performance of wireless communication transceivers is addressed. The building block that determines the efficiency and battery life of the entire mobile handset is the power amplifier. Modulations with large peak to average power ratio severely degrade efficiency in the conventional fixed-biased power amplifiers (PAs). To address this challenge, a novel PA is proposed with an adaptive load for the PA to improve efficiency. A nonlinearity cancellation technique is also proposed to improve linearity of the PA to satisfy the EVM and ACLR specifications. Ultra wide-band (UWB) systems are attractive due to their ability for high data rate, and low power consumption. In spite of the limitation assigned by the FCC, the coexistence of UWB and NB systems are still an unsolved challenge. One of the systems that is majorly affected by the UWB signal, is the 802.11a system (5 GHz Wi-Fi). A new analog solution is proposed to minimize the interference level caused by the impulse Radio UWB transmitter to nearby narrowband receivers. An efficient 400 Mpulse/s IR-UWB transmitter is implemented that generates an analog UWB pulse with in-band notch that covers the majority of the UWB spectrum. The challenge in receiver (RX) design is the over increasing out of blockers in applications such as cognitive and software defined radios, which are required to tolerate stronger out-of-band (OB) blockers. A novel RX is proposed with a shunt N-path high-Q filter at the LNA input to attenuate OB-blockers. To further improve the linearity, a novel baseband blocker filtering techniques is proposed. A new TIA has been designed to maintain the good linearity performance for blockers at large frequency offsets. As a result, a +22 dBm IIP3 with 3.5 dB NF is achieved. Another challenge in the RX design is the tough NF and linearity requirements for high performance systems such as carrier aggregation. To improve the NF, an extra gain stage is added after the LNA. An N-path high-Q band-pass filter is employed at the LNA output together with baseband blocker filtering technique to attenuate out-of-band blockers and improve the linearity. A noise-cancellation technique based on the frequency translation has been employed to improve the NF. As a result, a 1.8dB NF with +5 dBm IIP3 is achieved. In addition, a new approach has been proposed to reject out of band blockers in carrier aggregation scenarios. The proposed solution also provides carrier to carrier isolation compared to typical solution for carrier aggregation

    High Performance RF and Basdband Analog-to-Digital Interface for Multi-standard/Wideband Applications

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    The prevalence of wireless standards and the introduction of dynamic standards/applications, such as software-defined radio, necessitate the next generation wireless devices that integrate multiple standards in a single chip-set to support a variety of services. To reduce the cost and area of such multi-standard handheld devices, reconfigurability is desirable, and the hardware should be shared/reused as much as possible. This research proposes several novel circuit topologies that can meet various specifications with minimum cost, which are suited for multi-standard applications. This doctoral study has two separate contributions: 1. The low noise amplifier (LNA) for the RF front-end; and 2. The analog-to-digital converter (ADC). The first part of this dissertation focuses on LNA noise reduction and linearization techniques where two novel LNAs are designed, taped out, and measured. The first LNA, implemented in TSMC (Taiwan Semiconductor Manufacturing Company) 0.35Cm CMOS (Complementary metal-oxide-semiconductor) process, strategically combined an inductor connected at the gate of the cascode transistor and the capacitive cross-coupling to reduce the noise and nonlinearity contributions of the cascode transistors. The proposed technique reduces LNA NF by 0.35 dB at 2.2 GHz and increases its IIP3 and voltage gain by 2.35 dBm and 2dB respectively, without a compromise on power consumption. The second LNA, implemented in UMC (United Microelectronics Corporation) 0.13Cm CMOS process, features a practical linearization technique for high-frequency wideband applications using an active nonlinear resistor, which obtains a robust linearity improvement over process and temperature variations. The proposed linearization method is experimentally demonstrated to improve the IIP3 by 3.5 to 9 dB over a 2.5–10 GHz frequency range. A comparison of measurement results with the prior published state-of-art Ultra-Wideband (UWB) LNAs shows that the proposed linearized UWB LNA achieves excellent linearity with much less power than previously published works. The second part of this dissertation developed a reconfigurable ADC for multistandard receiver and video processors. Typical ADCs are power optimized for only one operating speed, while a reconfigurable ADC can scale its power at different speeds, enabling minimal power consumption over a broad range of sampling rates. A novel ADC architecture is proposed for programming the sampling rate with constant biasing current and single clock. The ADC was designed and fabricated using UMC 90nm CMOS process and featured good power scalability and simplified system design. The programmable speed range covers all the video formats and most of the wireless communication standards, while achieving comparable Figure-of-Merit with customized ADCs at each performance node. Since bias current is kept constant, the reconfigurable ADC is more robust and reliable than the previous published works

    Enabling Technologies for Distribution of Broadband Radio over Fiber

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    RÉSUMÉ La radio sur fibre (RoF) a été considérée comme une technologie prometteuse qui concurrencera de manière indisputable comme solution viable pour la distribution des systèmes de communication sans fil à bande large actuels et futurs. La technologie RoF emploie la modulation d'onde sous-porteuse (SCM) pour moduler la lumière par un signal RF, qui à son tour sera transmise par la fibre. Malheureusement, la transmission du signal RF sur la fibre est sujette à un certain nombre de défauts. Ces défauts incluent le faible rendement de la conversion optique en électrique, à la dispersion chromatique de la fibre, et à la non-linéarité de l’émetteur optique. L'objectif de cette thèse est de développer des technologies de pointe pour la radio sur fibre à large bande. Les conceptions proposées devraient adresser la déformation non linéaire induite par l'émetteur optique, combattre le problème de l’affaiblissement de la puissance optique induit par la dispersion chromatique de la fibre, et améliorer l'efficacité de modulation optique au petit signal sans augmenter de manière significative le cout et la complexité du système RoF. Pour le signal RF à large bande, nous considérons le signal à bande ultra large utilisant le multiplexage par répartition orthogonale de la fréquence (ULB MB-MROF), qui a été proposé comme solution pour le réseau de secteur personnel sans fil d’IEEE 802.15.3a (WPAN). D'abord, la performance de la transmission de l'ULB MB-MROF par la fibre est étudiée en considérant l'impact de modulation et démodulation optique. L'analyse théorique de l'effet de la dispersion de la fibre, de la réponse de l'émetteur optique et du récepteur optique sur la performance du système est effectuée en considérant la distorsion de la phase et de l'amplitude. Des expériences sont réalisées pour vérifier notre analyse théorique et une bonne concordance est obtenue. Il est constaté que l'index de modulation RF de ~4% est optimum pour l'émetteur optique avec le modulateur de Mach-Zehnder, et le récepteur optique avec la réponse de Tchebychev-II est le meilleur pour l'ULB MB-MROF sur fibre. Aussi, la performance de la transmission sans fil est limitée par la sensibilité du récepteur ULB MB-MROF. Il est aussi trouvé qu’une haute puissance optique reçue est exigée pour la transmission du signal de l'ULB MB-MROF sur fibre.----------ABSTRACT Radio over fiber (RoF) has been considered as a very promising technology that will indisputably compete as a viable solution for the distribution of current and future broadband wireless communication systems such as IEEE 802.15.3a WPAN using Multiband-Orthogonal Frequency Division Multiplexing Ultra-Wideband (MB-OFDM UWB) signal. The RoF technology makes use of subcarrier modulation (SCM) to modulate an RF signal on light, which in turn will be transmitted by optical fiber. Unfortunately, the transmission of RF signal over fiber is subject to a number of impairments. These impairments include: low optical to electrical conversion efficiency, fiber chromatic dispersion, and nonlinearity of the optical front end, etc.. The objective of this thesis is to develop enabling technologies for broadband RoF systems. The proposed design platforms and techniques should address nonlinear distortion induced by the optical transmitter; combat optical power fading issue induced by the chromatic dispersion; and improve modulation efficiency of the optical small-signal modulation without significantly adding excessive expense and complexity to the RoF system. First of all, the performance of MB-OFDM UWB wireless over fiber transmission system is investigated considering optical modulation and demodulation aspects. Theoretical analysis of the effects of fiber chromatic dispersion, relative intensity noise (RIN), optical transmitter and optical receiver response on system performance is carried out considering amplitude and phase distortion. Experiments are conducted, which have verified our theoretical analysis and a good agreement is obtained. It is found that low RF modulation index (4%) for optical transmitter with Mach-Zehnder modulator (MZM), and optical receiver with Chebyshev-II response is the best for MB-OFDM UWB over fiber. The wireless transmission performance is limited by the UWB receiver sensitivity. Moreover, a high received optical power is required for transmission of MB-OFDM UWB signal over fiber. It is also found that the parameters like laser output power, laser linewidth and fiber dispersion that control RIN, will critically affect the overall performance of a UWB over fiber system
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