Ultra-wideband Transmitter Research Articles

Design and simulation of pulse generator for UWB based on LC-tank differential oscillators topology

This paper presents a detailed analysis, design and simulation of pulse generator for Ultra-Wideband (UWB) based on LC-tank differential oscillators topology. The differential oscillators with a cross-coupled NMOS pair and a tail current source are used to achieve more positive gain and generate negative resistance to the LC-tank. Besides, this oscillator is suitable for UWB high frequency and low power applications. The UWB pulse generator is composed of a simple on-off keying (OOK) modulated and LC-tank differential oscillators. The circuit of UWB pulse generator designed and simulated in 0.13 um CMOS technology. The UWB pulse generator generates a pulse for the 6 - 10 GHz UWB transmitter. Simulation results show a pulse width of 586 ps, a peak to peak amplitude pulse of 88.6 mV from the 1.2 V power supply and the die area of 0.22 mm2. The average power consumption of approximately 0.55 mW and an energy consumption of 1.1 pJ/pulse at 500 MHz pulse repetition rate (PRR) are observed.

A Wireless FSCV Monitoring IC With Analog Background Subtraction and UWB Telemetry.

A 30-μW wireless fast-scan cyclic voltammetry monitoring integrated circuit for ultra-wideband (UWB) transmission of dopamine release events in freely-behaving small animals is presented. On-chip integration of analog background subtraction and UWB telemetry yields a 32-fold increase in resolution versus standard Nyquist-rate conversion alone, near a four-fold decrease in the volume of uplink data versus single-bit, third-order, delta-sigma modulation, and more than a 20-fold reduction in transmit power versus narrowband transmission for low data rates. The 1.5- mm(2) chip, which was fabricated in 65-nm CMOS technology, consists of a low-noise potentiostat frontend, a two-step analog-to-digital converter (ADC), and an impulse-radio UWB transmitter (TX). The duty-cycled frontend and ADC/UWB-TX blocks draw 4 μA and 15 μA from 3-V and 1.2-V supplies, respectively. The chip achieves an input-referred current noise of 92 pA(rms) and an input current range of ±430 nA at a conversion rate of 10 kHz. The packaged device operates from a 3-V coin-cell battery, measures 4.7 × 1.9 cm(2), weighs 4.3 g (including the battery and antenna), and can be carried by small animals. The system was validated by wirelessly recording flow-injection of dopamine with concentrations in the range of 250 nM to 1 μM with a carbon-fiber microelectrode (CFM) using 300-V/s FSCV.

A Low-Power Low-Complexity Transmitter for FM-UWB Systems

A frequency modulated ultra-wideband (FM-UWB) transmitter with a high-robust relaxation oscillator for subcarrier generation and a dual-path Ring VCO for RF FM is proposed, featuring low power and low complexity. A prototype 3.65-4.25 GHz FM-UWB transceiver employing the presented transmitter is fabricated in 0.18 μm CMOS for shortrange wireless data transmission. Experimental results show a bit error rate (BER) of 10SUP?6/SUP at a data rate of 12.5 kb/s with a communication distance of 60 cm is achieved and the power dissipation of 4.3 mW for the proposed transmitter is observed from a 1.8 V supply.

High-Robust Relaxation Oscillator with Frequency Synthesis Feature for FM-UWB Transmitters

A CMOS relaxation oscillator, with high robustness over process, voltage and temperature (PVT) variations, is designed in 0.18 μm CMOS. The proposed oscillator, consisting of full-differential charge-discharge timing circuit and switchedcapacitor based voltage-to-current conversion, could be expanded to a simple open-loop frequency synthesizer (FS) with output frequency digitally tuned. Experimental results show that the proposed oscillator conducts subcarrier generation for frequency-modulated ultra-wideband (FM-UWB) transmitters with triangular amplitude distortion less than 1%, and achieves frequency deviation less than 8% under PVT and phase noise of ?112 dBc/Hz at 1 MHz offset frequency. Under oscillation frequency of 10.5 MHz, the presented design has the relative FS error less than 2% for subcarrier generation and the power dissipation of 0.6 mW from a 1.8 V supply.

A 750 μW 3.5–4.5 GHz FM-UWB transmitter

This paper presents an ultra-low power frequency modulated ultra-wideband (FM-UWB) transmitter implemented in standard 130nm CMOS technology. The transmitter operates in the range of 3.5–4.5GHz with 4GHz RF carrier frequency. The transmitter can accept input data rates up to 250kbps. A relaxation oscillator is used to generate the subcarrier signal and a VCO for RF carrier generation. The center frequency of the VCO is periodically calibrated to avoid out of band operation. An integer-N phase-locked loop (PLL) is used for both subcarrier generation and RF VCO calibration, which needs only 500ns to complete the calibration. A class-AB power amplifier is used to output the power under the FCC mask. The proposed FM-UWB transmitter consumes 750μW from a 1.2V supply.

Time-domain UWB transmission model for three-dimensional environments with low-loss obstacles

In this work, time-domain (TD) solution is presented for ultra wideband (UWB) transmission through three dimensional (3-D) scenarios made up of low-loss dielectric materials. Considering soft and hard polarizations, propagation through different structures like building and wedge is analyzed with arbitrary position of the receiver (Rx). Further the presented TD solution for transmission has been compared with TD UWB diffraction; single diffraction, double diffraction and diffraction followed by reflection when both transmitter (Tx) and Rx are in a plane normal to the edge. A detailed analysis of attenuation and distortion of transmitted and diffracted pulse waveforms through lossy obstacles is presented. It is observed that transmitted pulse waveform suffers comparatively lesser attenuation and distortion in shape as compared to diffracted pulse for low-loss obstacles. The TD results have been validated with the inverse fast Fourier transform (IFFT) of the corresponding exact frequency-domain (FD) results.

Concurrent Dual-Band Modeling and Digital Predistortion in the Presence of Unfilterable Harmonic Signal Interference

Motivated by advanced-generation signals and corresponding trends for multiband, broadband, and ultra-wideband transmitters, several models have recently been proposed for digital predistortion in a dual-band concurrent transmission. These state-of-the-art models assume that two frequencies of operation are uncorrelated and harmonic products can be filtered out. However, when the harmonic of one signal falls on the frequency band of another signal, it cannot be removed with filters. This paper proposes a 3-D harmonic memory polynomial based model for the dual-band concurrent transmission in the presence of harmonic interferences. The model is extracted and predistortion is implemented using a low-cost field-programmable gate-array-based system including a transmitter and a feedback receiver. Using the proposed model, a performance improvement up to 22 dB in terms of normalized mean square error and performance improvement up to 20 dB in terms of the adjacent channel power ratio is achieved compared to a conventional dual-band memory polynomial model not including harmonics.

2-D Polynomial-Based Model for the Dual-Band Concurrent Transmission in the Presence of Harmonic Interferences

Generation of signals and corresponding trends for multiband, broadband, and ultra-wideband transmitters employ several models, some of which causes predistortion in a dual-band concurrent transmission. Two frequencies of operation are uncorrelated and harmonic products can be filtered out. However, when the harmonic of one signal falls on the frequency band of another signal, it cannot be removed with filters. This paper presents a 2-D harmonic polynomial based model for thedual-band concurrent transmission in the presence of harmonic interferences. Predistortion is implemented using a transmitter and a feedback receiver. With this model, a performance improvement of up to 22 dB in terms of normalized mean square error and performance improvement of up to 20 dB in terms of the adjacent channel power ratio is achieved compared to a dual-band polynomial model without harmonics.

A Wireless-Powered IR-UWB Transmitter for Long-Range Passive RFID Tags in 90-nm CMOS

An impulse radio ultrawideband (IR-UWB) transmitter (TX) intended for long-range passive radio-frequency (RF) identification tags is presented. It is wirelessly powered by an ultrahigh-frequency (UHF) signal. A 128-bit pseudonoise code is transmitted when enough energy is harvested. A new on-off-keying multicycle energy-efficient IR-UWB pulse generator (PG) is proposed, and a co-design with power management circuits is introduced to improve the system supply noise performance. A novel injection-locking divider co-designed with an RF voltage rectifier is proposed to eliminate the injection input resistive load that exists in some designs; otherwise, the input sensitivity would be degraded. A proof-of-concept prototype is fabricated in a TSMC 90-nm CMOS process. Measurements show the TX input sensitivity to be approximately -17.5 dBm with a 900-MHz UHF input. The measured PG output swing is 195 mV <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p-p</sub> with a -10 dB bandwidth of approximately 3.4 GHz.

A Sub-GHz Mostly Digital Impulse Radio UWB Transceiver for Wireless Body Sensor Networks

This paper presents a mostly digital impulse radio (IR) ultra-wideband (UWB) transceiver for low power wearable and implantable biomedical devices. The UWB transmitter adopts carrier-less all-digital pulse generator with on-off keying (OOK) modulation, and uses an 11-bit Barker code for reliable communication in the frequency range of 0-960 MHz. The receiver is based on auto-threshold detection. The only RF block in the receiver is the low-noise amplifier (LNA), and this LNA operates intermittently for better power efficiency. The timing window for incoming data is provided by a delay locked loop (DLL). This DLL could synchronize the receiver clock to the incoming data. Fabricated in a standard 0.35- μm CMOS technology, the prototype chip achieves energy efficiency of 100 and 600 pJ/pulse for the transmitter and receiver, respectively.

Power Efficient Ultra Wide Band Based Wireless Body Area Networks with Narrowband Feedback Path

The basic requirement of wireless healthcare monitoring systems is to send physiological signals acquired from implantable or on-body sensor nodes to a remote location. Low-power consumption is required for wireless healthcare monitoring systems since most medical sensor nodes are battery powered. The emergence of new technologies in measuring physiological signals has increased the demand for high data rate transmission systems. Ultra-wide band (UWB) is a suitable wireless technology to achieve high data rates while keeping power consumption and form factors small. Although UWB transmitters are designed based on simple techniques, UWB receivers require complex hardware and consume comparatively higher power. In order to achieve reliable low power two-way communication, a sensor node can be constructed using a UWB transmitter and a narrow band receiver. This paper proposes a new medium access control (MAC) protocol based on a dual-band physical layer technology. Co-simulation models based on MATLAB and OPNET have been developed to analyze the performance of the proposed MAC protocol. We analyzed the performance of the MAC protocol for a realistic scenario where both implantable and wearable sensor nodes are involved in the data transmission. Priority-based packet transmission techniques have been used in the MAC protocol to serve different sensors according to their QoS requirements. Analysis is done with regard to important network parameters, such as packet loss ratio, packet delay, percentage throughput, and power consumption.

Performance evaluation on FPGA-implemented UWB-IR receiver for in-body to out-of-body communication systems.

In order to design an optimized transceiver structure of ultra wideband (UWB) transmission in in-body to out-of-body communications, it is necessary to make the transceiver structure be easily adjustable in order to realize a good communication performance in an experimental environment. For this purpose, we first implement our develop UWB-impulse radio (IR) receiver structure for the in-body to out-of-body communication in a field programmable gate array (FPGA) board, and evaluate the fundamental communication performance of the FPGA-implemented UWB-IR receiver by a biological-equivalent liquid phantom experiment. The FPGA configuration results indicate that our FPGA realization of the UWB-IR receiver has accomplished good communication performance with few FPGA slices. Moreover, the evaluation results in the liquid phantom experiment show that the FPGA-implemented UWB-IR receiver can achieve a bit error rate (BER) of 10(-3) up to a communication distance of 70 mm with ensuring a high data rate of 2 Mbps.

The Kitchen Vehicle Pressure Autocontrol System Based on SC-UWB Technology of Internet Things

This research was carried out according to the actual needs of plateau kitchen vehicle. However, these military equipments have played important roles in the military exercises, earthquake relief, and other major activities, they does need urgent improvements in the using process. Among those problems to be solved, drift distortion of pressure cooker signal transmission on account of low temperature of high altitude, inability of achieving accurate control, and untimely feedback of service demand included. The pressure automatic control system of plateau kitchen vehicle which is based on Single Carrier Ultra Wide Band (UWB) wireless technology (SC-UWB), will completely solve the above problems, and the followings are innovations of this study: Firstly, Single-carrier ultra-wideband wireless transmission technology was used in this study, which was in accordance with Chinese Standard and based on chips produced by China. This would satisfy the needs of real-time transmission in pressure and temperature information under extreme environment, and solve technical problems such as signal integrity and communicational confidentiality, and this would also eliminate technical problems such as signal distortion, hysteresis, drift, high deviation repeatability of automatic control system of plateau kitchen vehicle in extreme environment. Secondly, intelligent sensor systems were connected to the Internet of things (IOT). To develop Industrial Personal Computer (IPC) according to the management system and daily use of this equipment and to lead the equipment to have node function of access to the Internet of things, would be the foundation of all kinds of beneficial exploration in the management of Internet of things, and also the guarantee of technology standard of Internet of things in military equipment of future. Then, the existing equipment can smoothly be switched in to avoid duplication of investment.

Nanostructured CMOS Wireless Ultra-Wideband Label-Free PCR-Free DNA Analysis SoC

A fully integrated 54-channel wireless fast-scan cyclic voltammetry DNA analysis SoC is presented. The microsystem includes 546 3D nanostructured and 54 2D gold DNA sensing microelectrodes as well as 54 pH sensors. Each channel consists of a chopper-stabilized current conveyer with dynamic element matching. It is utilized as the amperometric readout circuit with a linear resolution from 8.6 pA to 350 nA. The on-chip programmable waveform generator provides a wide range of user-controlled rate and amplitude parameters with a maximum scan range of 1.2 V, and scan rate ranging between 0.1 mV/sec to 300 V/sec. A digital ultra-wideband transmitter based on a delay line architecture provides wireless data communication with data rates of up to 50 Mb/sec while consuming 400 µW. The 3 mm × 3 mm prototype fabricated in a 0.13 µm standard CMOS technology has been validated in prostate cancer synthetic DNA detection with 10 aM label-free PCR-free detection limit. Each channel occupies an area of only 0.06 mm 2 and consumes 42 µW of power from a 1.2 V supply.

A DIFFERENTIAL K-BAND UWB TRANSMITTER FOR SHORT RANGE RADAR APPLICATION WITH CONTINUOUS RUNNING LOCAL OSCILLATOR

The design of a difierential K-band UWB (Ultra Wideband) Short Range Radar (SRR) transmitter in 90nm bulk CMOS is presented. Implementation of SRRs in deep submicron CMOS technology is attractive, in terms of cost and monolithic integration of RF font-end with signal base- band processor. The transmitted pulse bandwidth limits the range resolution of the radar system. Due to the wide bandwidth and high frequency of CMOS implementation, UWB transmitters in the K-band are challenging to make and critical for the system performance. The design presented is based on frequency up conversion using a double balanced mixer. The difierential output is combined and matched with the antenna using an on-chip balun. To mitigate local oscillator (LO) leakage of UWB difierential transmitters we propose a new Pulse Generator (PG) design. A switching technique is used to minimize the LO leakage enabling continuous wave operation with very wideband pulses. Measurements of the proposed transmitter achieves a i10dB bandwidth (BW) of 5GHz. Using a Pulse Repetition Frequency (PRF) of 100MHz the peak average power is i40dBm. Compared to measured transmitter performance of a single balanced mixer design, the LO leakage of this dual balanced mixer is decreased with more than 20dB, and is lower than the peak average power of the pulse. It consumes 11mW from a 1.2V supply where 6mW is from the LO.

A Subgigahertz UWB Transmitter With Wireless Clock Harvesting for RF-Powered Applications

A subgigahertz ultrawideband (UWB) transmitter (TX) with wireless clock harvesting is presented for RF-powered applications such as RF identifications and implantable devices in the 180-nm CMOS process. The proposed low-power TX consists of a harmonic injection-locked ring oscillator (ILRO), a synchronized pulse generator, and a driver stage. Through wireless injection locking, a 450-MHz carrier is extracted using the subharmonic of an ultrahigh frequency signal radiated by a reader. Following the ILRO, the carrier is gated and amplified to generate the UWB pulses. This approach avoids power-hungry frequency synthesis circuitry and bulky crystal reference, and it relaxes the timing synchronization between the reader and the tag. Due to aggressive duty cycling and the fast setup time (<; 50 ns at an input power of -15 dBm), the proposed TX is power scalable with an energy consumption of 35 pJ/pulse. To comply with the Federal Communications Commission regulations, the maximum pulse rate is up to 5 MHz with a peak-to-peak pulse amplitude of 0.75 V and a corresponding power consumption of 175 μW, which is favorable to RF-powered applications.

Experimental Evaluation of Implant UWB-IR Transmission With Living Animal for Body Area Networks

One of promising transmission technologies in wireless body area networks (BANs) is ultra-wideband (UWB) communication, which can provide high data rate for real-time transmission, and extremely low power consumption for increasing device longevity. However, UWB signals suffer from large attenuation in a wireless communication link, especially in implant BANs. Although several investigations on channel characterization have been far thus conducted for evaluating the UWB transmission performance, they have been limited to either computer simulations or experiments with biological-equivalent phantoms. Experimental evaluation with a living body has rarely been conducted, i.e., the performance in real implant BANs has been scarcely discussed. In this paper, therefore, we focus on a living animal experimental evaluation on the UWB transmission performance. To begin with, we develop an ultra-wideband impulse radio (UWB-IR) communication system with a multipulse pulse position modulation scheme, and then analyze the fundamental characteristics of the developed UWB-IR communication system by a liquid phantom experiment. Finally, we evaluate the performance of the developed UWB-IR communication system via the living animal experiment. From the experimental results, although we have observed that the path loss is more than 80 dB, the developed system can achieve a bit error rate of 10-2 within the communication distance of 120 mm with ensuring a high data rate of 1 Mb/s. This result first time gives a quantitative communication performance evaluation for the implant UWB transmission in a living body.

Wavelength Reuse in a UWB Over WDM-PON Based on Injection Locking of a Fabry–Pérot Laser Diode and Polarization Multiplexing

Wavelength reuse in a symmetric ultra-wideband (UWB) over wavelength-division-multiplexing passive optical network based on injection locking of a Fabry-Pérot laser diode (FP-LD) and polarization multiplexing is proposed and experimentally demonstrated. In the proposed scheme, the downstream UWB signal and baseband signal are generated and polarization multiplexed in the central station and sent to a base station (BS) over an optical fiber. At the BS, one of the downstream signals is selected to injection lock the FP-LD. It is demonstrated theoretically and experimentally that the upstream service performance is less sensitive to the modulation depth of the downstream UWB signal than the baseband signal, and the use of the downstream UWB signal as the injection signal would contribute to a better transmission performance for both the downstream and upstream services. Thus, the downstream UWB signal is selected as the injection signal. An experiment is performed. When the FP-LD is injection locked by a downstream UWB signal, a clear optical carrier is generated which is reused for upstream UWB and baseband transmission. A bidirectional point-to-point transmission of 1.25 Gb/s UWB signal and 10 Gb/s baseband signal over 25-km single-mode fiber using a single wavelength is demonstrated. The bit error rate performances and the eye diagrams for both downstream and upstream transmissions are measured.

Hybrid UWB and WiMAX radio-over-multi-mode fibre for in-building optical networks

In this paper the use of hybrid WiMedia-defined ultra-wideband (UWB) and IEEE 802.16d WiMAX radio-over-fibre is proposed and experimentally demonstrated for multi-mode based in-building optical networks with the advantage of great immunity to optical transmission impairments. In the proposed approach, spectral coexistence of both signals must be achieved with negligible mutual interference. The experimental study performed addressed an indoor configuration with 50 μm multi-mode fibres (MMF) and 850 nm vertical-cavity surface-emitting laser (VCSEL) transmitters. The results indicate that the impact of the wireless convergence in radio-over-multi-mode fibre (RoMMF) is significant for UWB transmissions, mainly due to MMF dispersion and electrooptical (EO) devices with limited bandwidth. On the other hand, WiMAX transmission is feasible for a 300 m MMF and 30 m wireless link in the presence of UWB, with −31 dBm WiMAX EVM.

A 90-nm CMOS UWB Impulse Radio Transmitter With 30-dB In-Band Notch at IEEE 802.11a System

In spite of the FCC regulations, the coexistence of ultra-wideband (UWB) and narrowband (NB) systems is still an unsolved challenge. A UWB transmitter (TX) can severely degrade the performance of an IEEE 802.11a system. In this paper, a fully integrated analog impulse-radio UWB TX is presented that generates a novel UWB pulse with a tunable notch at the frequency of IEEE 802.11a system. The pulse has a 5.5-GHz bandwidth (BW), which makes it suitable for high-resolution high data-rate applications. The TX has a maximum pulse rate of 400 Mpulse/s and energy of 65 pJ/pulse with a power supply of 1.2 V. The measurement results show that the pulse has a 30-dB notch, and the TX power inside the BW of the NB system is less than -78 dBm/MHz. The TX has a biphase modulation and has been fabricated in a 90-nm CMOS process. The proposed pulse meets the Federal Communications Commission mask for UWB systems.