Impulse Radio Ultra-wideband Pulse Generator Research Articles

A Tunable CMOS IR-UWB Pulse Generator Based on Feedback Controlled Oscillator Switching

This brief presents a tunable Impulse-Radio Ultra-Wideband (IR-UWB) pulse generator based on feedback oscillator switching. The circuit provides a wide range of pulse amplitude and width tuning, thus enabling the required pulse shaping for a desired pulse repetition rate and/or a wireless transmission range. Feedback controlled switching prevents the potential omission of the UWB pulse generation and provides low UWB pulse energy variations at low bias currents and a wide temperature range, ensuring system robustness with respect to temperature variations. The pulse amplitude is tunable within 0.27 Vpp to 2.05 Vpp, while the pulse width tuning range is 1-6.5 ns. The total energy consumption of the IR-UWB pulse generator at the 50 Mpps pulse repetition rate is equal to 25.4 pJ/pulse for the pulse amplitude equal to 0.27 Vpp, while for the pulse amplitude equal to 2.05 Vpp, it is increased up to 99.8 pJ/pulse. The circuit occupies a core area of 0.56 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> in a 0.18 μm CMOS technology.

Circuit analysis and optimisation of the high‐voltage high‐efficiency IR‐UWB pulse generator for ranging and radar application

An in-depth circuital analysis of an energy-efficient high peak power impulse radio ultra-wideband (IR-UWB) pulse generator monolithic microwave integrated circuit (MMIC) design is presented. The proposed IR-UWB pulse generation process is explained in detail. A trade-off between the peak output power level and the frequency of operation is discussed. The proposed circuit is optimised for the highest possible peak output power in the 3–5 GHz UWB band for ranging and radar application. The presented IR-UWB pulse former makes use of the cascode heterojunction bipolar transistor (HBT) configuration for signal scaling operation instead of the common emitter configuration. The proposed cascode pair configuration results in higher output voltage swing as well as reduced power consumption. The effect of coupling capacitors on amplification factor of the pulse former stages as well as impedance profile of the distributed transmission line is discussed in great detail. The temperature-dependent parasitic component in the proposed circuit is studied. Its effect on the transient behaviour of the proposed IR-UWB pulse generator is analysed, which is important for IR-UWB beamforming applications. The required mathematical model for the parasitic effect is derived and explained.

An Energy Efficient Multi-User Asynchronous Wireless Transmitter for Biomedical Signal Acquisition.

The paper presents a novel transmitter architecture for short-range asynchronous wireless communication, applicable to simultaneous multi-user wireless acquisition of biological signals. The analog signal, provided from an analog biosensor, is transformed to time information using an Integral Pulse Frequency Modulator (IPFM) as a Time-Encoding Machine. The IPFM generates a time-encoded unipolar pulse train, maintaining the linear dependence of the output pulse distance on analog input voltage. The system enables continuous acquisition of the signals from multiple sensors in which each transmitter has unique feedback loop delay used for multi-user coding. IPFM pulses trigger the Impulse Radio Ultra-Wideband pulse generator directly, providing two ultra-wideband (UWB) pulses per each IPFM pulse. Due to the lack of internal clock signal and microprocessor-free multi-user coding, the circuitry satisfies the requirements of multi-user coding energy efficiency and size reduction, which are crucial demands in biomedical applications. The proposed Time-Encoded UWB (TE-UWB) transmitter is implemented in 0.18 [Formula: see text] CMOS technology. Measurement results of the IPFM transfer function for input voltage ranging from 0.15 to 1.5 V are presented, providing the dependence of the IPFM pulse time distance on analog input voltage and power consumption dependence on the input voltage level. For continuous monitoring operation, total power consumption of the transmitter circuitry for the maximum input voltage is 10.8 [Formula: see text], while for the lowest input voltage it increases to 40.48[Formula: see text]. The circuit occupies 0.14 [Formula: see text].

A 200-Mb/s Data Rate 3.1–4.8-GHz IR-UWB All-Digital Pulse Generator With DB-BPSK Modulation

A new all-digital impulse radio ultrawideband pulse generator in a 65-nm CMOS technology for a wireless body area network is presented. The system architecture is a delay-based pulse generator that is designed using only logic gates to minimize the power consumption. The system uses a frequency range of 3.1–4.8 GHz and 3 channels with a 500-MHz bandwidth. The maximum data rate of this system is 100 Mb/s with pulse positioned modulation and 200 Mb/s with on–off keying. Delay-based binary phase-shift keying is used to achieve an efficient spectral line characteristic. The total power consumption of the pulse generator is 30 pJ/pulse at a 1.2-V supply voltage without a static bias current.

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.

New design of low power, 100 Mb-s IR-UWB pulse generator in 0.18 µm CMOS technology

A new method of impulse radio ultra-wideband (IR-UWB) pulse generation, with advantage of providing a “notch” like representation of pulse in the spectrum domain for particular control parameters values, is investigated in this paper. Low power pulse generator is composed of a glitch generator, a switched oscillator, a two-stage buffer and a pulse shaping filter. The proposed architecture, designed in UMC 0.18µm CMOS technology, can operate in a single band from 3.3GHz to 9.3GHz or in a double, lower and higher UWB band (from 3GHz to 9.15GHz), suppressing frequencies in the WLAN band. Both spectrums fully comply with the corresponding FCC spectral mask, while the pulse generator regime and the spectrum range are determined by control signal values. Post-layout simulation results showed a pulse width of 0.5ns, and a peak-to-peak amplitude of 211mV for one band spectrum. The average power consumption is 0.89mW corresponding to the energy consumption of 8.9pJ/pulse for 100MHz pulse repetition rate (PRF). The pulse duration is 1ns and peak-to-peak amplitude is 202mV in the case of the WLAN frequency band suppression. The total chip area is 0.31mm2. The pulse generator has been evaluated for the best performance supporting the on-off keying (OOK) modulation.

Power-efficient impulse radio ultrawideband pulse generator based on the linear sum of modified doublet pulses

We propose a new and power-efficient impulse radio ultawideband (IR-UWB) pulse design concept. The proposed concept is based on a linear sum of modified doublet pulses. The proposed concept is both simulated and experimentally demonstrated. The experimental demonstration employs a photonic scheme that generates the designed pulse using two main steps, mainly optical shaping and differential detection. The optical shaping is performed using a single electro-optic modulator biased in the nonlinear portion of its transfer function, and the differential detection is performed using a balanced photodetector. The generated IR-UWB pulse is fully Federal Communications Commission compliant, even in the highly power-restricted global positioning system band. The proposed optical scheme has potential to be integrated on a compact optical chip and thus suitable for reliable, low-cost, high-speed, short-range UWB wireless access, such as in-building networks.