Ultra-wideband Receiver Research Articles

Positioning system on impulse ultrawideband fields

Background: The systems of positioning on the base of radiowaves are widely used both in a global scale and for the exact position-finding of objects indoors. Global systems of positioning usually need valuable high-quality time synchronization, assume substantial errors at improper weather, at falling of radio waves on the earth surface at small angles, shading of transceivers by large obstacles, and at presence of radio electronic interferences of different nature. Objectives Investigation of the new system of positioning on the ultrawideband impulse electromagnetic fields and their analysis by an artificial neural network is proposed. Materials and methods: The phenomenon of the pulse form change on angle of radiation by antenna is used for the determination of the position of ultrawideband receiver. At first, the two-dimensional case of the problem is considered. Exciting two antennas separated at known distance by means of different impulse signals it is possible to define the place of location of receiver if we know the angles of arrival of impulses from each antenna. The ultrawideband bow-tie antennas excited by the Gaussian impulses of different durations are used as irradiators. The forms of the received impulses are calculated by method of Finite Differences in Time Domain (FDTD). The classification of the time forms of the received electromagnetic waves from different antennas at different angles of radiation is carried out by a deep neural network. Results: It is shown that for the classification the artificial neural network pays special attention to the intervals of time where the received impulse changes quickly. The four-layer network faultlessly distinguishes the obtained signals from different antennas. The numerical calculation of the electromagnetic problem and artificial neural network training show the possibility of determination of angles of radiation by the network with the accuracy of one degree excepting some cases. Using the basis between antennas of 50 meters the precision of receiver position determination is not worse than 62 cm in the square domain of 50 meter size eliminating some angles where the accuracy falls to 2 meters. Conclusion: Property of antennas to change the form of radiated ultrawideband impulses for different angles can be used for the construction of the new system of positioning that does not need the time synchronization with transmitters. The proposed system can be effectively employed indoors. The distinctive feature of the impulse electromagnetic wave positioning system is its immunity to the existent narrowband electromagnetic waves.

Front-End Module of 18–40 GHz Ultra-Wideband Receiver for Electronic Warfare System

In this study, we propose an approach for the design and satisfy the requirements of the fabrication of a small, lightweight, reliable, and stable ultra-wideband receiver for millimeter-wave bands and the contents of the approach. In this paper, we designed and fabricated a stable receiver with having low noise figure, flat gain characteristics, and low noise characteristics, suitable for millimeter-wave bands. The method uses the chip-and-wire process for the assembly and operation of a bare MMIC device. In order to compensate for the mismatch between the components used in the receiver, an amplifier, mixer, multiplier, and filter suitable for wideband frequency characteristics were designed and applied to the receiver. To improve the low frequency and narrow bandwidth of existing products, mathematical modeling of the wideband receiver was performed and based on this spurious signals generated from complex local oscillation signals were designed so as not to affect the RF path. In the ultra-wideband receiver, the gain was between 22.2 dB and 28.5 dB at Band A (input frequency, 18–26 GHz) with a flatness of approximately 6.3 dB, while the gain was between 21.9 dB and 26.0 dB at Band B (input frequency, 26–40 GHz) with a flatness of approximately 4.1 dB. The measured value of the noise figure at Band A was 7.92 dB and the maximum value of noise figure, measured at Band B was 8.58 dB. The leakage signal of the local oscillator (LO) was –97.3 dBm and –90 dBm at the 33 GHz and 44 GHz path, respectively. Measurement was made at the 15 GHz IF output of band A (LO, 33 GHz) and the suppression characteristic obtained through the measurement was approximately 30 dBc.

A IR UWB Timed-Array Radar Based on 16-Channel Transmitter and Sampling Capacitor Reused Receiver

A ${4\times 4}$ impulse radio (IR) ultra-wide band (UWB) timed-array radar is proposed in this brief based on 16-channel all-digital transmitter and sampling capacitor reused receiver. 3-D beamforming is achieved by the 16-channel ( ${4\times 4}$ ) planar low power IR UWB beamforming transmitter. UWB receiver adopts energy detection and reuses the integrating capacitor as C-DAC within an 8-bit SAR ADC to save area and power consumption. Fabricated in 65-nm CMOS technology, the whole UWB radar occupies an active core area of 4.2 mm $^{{2}}$ . Delay range of 1.2 ns with 10 ps resolution is achieved, corresponding to 90° radar scanning range with 3° resolution when the ${4\times 4}$ planar array antenna spacing is 6 cm.

Parameter Estimation of SAR Signal Based on SVD for the Nyquist Folding Receiver.

The Nyquist Folding Receiver (NYFR) is a novel ultra-wideband (UWB) receiver structure that can realize wideband signal monitoring with fewer components. The NYFR induces a Nyquist zone (NZ)-dependent sinusoidal frequency modulation (SFM) by a modulated local oscillator (LOS), and the intercepted linear frequency modulated (LFM) synthetic aperture radar (SAR) signal will be converted into an LFM/SFM hybrid modulated signal. In this paper, a parameter estimation algorithm is proposed for the complicated NYFR output signal. According to the NYFR prior information, a chirp singular value ratio (CSVR) spectrum method based on singular value decomposition (SVD) is proposed to estimate the chirp rate directly before estimating the NZ index. Then, a fast search algorithm based on golden section method for the CSVR spectrum is analyzed, which can obviously reduce the computational complexity. The simulation shows that the presented algorithm can accurately estimate the parameters of the LFM/SFM hybrid modulated output signal by the NYFR.

Parameter estimation of LFM signal intercepted by improved dual‐channel Nyquist folding receiver

A Nyquist folding receiver (NYFR) is a novel ultra-wideband (UWB) receiver architecture, which can realise a wideband receiving with fewer components. Intercepted by the NYFR with a sinusoidal frequency modulation (SFM) local oscillator, a linear frequency modulation (LFM) signal will be converted into a LFM/SFM hybrid modulated signal. To simplify the processing of this kind of complicated signal, the authors propose improved dual-channel NYFR architecture with an efficient parameter estimation algorithm. Compared with the existing parameter estimation methods for the NYFR, the proposed architecture offers better estimation performance, higher signal type adaptability, and simpler operation.

Gallium arsenide 0.5–18 GHz antenna front‐end with integrated limiter and differential to single ended low‐noise amplifier

In this study, the authors present a 36:1 relative bandwidth active front-end low-noise amplifier (LNA) with power limiter that has been developed for airborne ultra-wideband receiver systems. The proposed system is driven by an external antenna with a balanced mode with an input impedance of 150 Ω. The whole microwave monolithic integrated circuit (MMIC) embeds a protection from the presence of high-level signals, an ultra-wideband amplifier circuit, an active balun and an impedance transformer. It has a bandwidth ranging from 0.5 to 18.0 GHz with 14 dB gain, 4.5 dB noise figure (NF), 20 dB common-mode rejection and 30 dBm input overload protection. The circuit has a single bias from the output port greatly simplifying its use within a receiving system and can be directly integrated into the antenna mechanical support. Test measurements are also provided.

Low‐power low data rate FM‐UWB receiver front end

This study introduces a frequency modulated ultra-wideband (FM-UWB) receiver optimised for low power and fast start-up. The receiver consists of a front end amplifier converting a frequency modulated signal to an amplitude modulated signal which is applied to an envelope detector. The receiver front end is for 500 MHz channels centred at 3450 and 3950 MHz. The amplifier uses passive gain and four cascaded gain stages to achieve high radio-frequency gain without the need for super-regeneration. By simplifying the architecture this way, the front end has a 5 μs wake-up time to enable efficient duty-cycling. The measured front end receives a signal at −68 dBm while consuming 600 μW of power (excluding a test buffer) from a 1 V supply. Fabrication was done using the IBM 130-nm CMOS technology on a 1 mm × 1 mm loose die.

Noncoherent IR-UWB Receiver Using Massive Antenna Arrays for Wireless Sensor Networks

Noncoherent impulse radio ultrawideband (UWB) receivers do not require channel state information and are also robust against pulse shape distortions. However, their performance is suboptimal, especially at low signal-to-noise ratios. In this article, we propose simple noncoherent UWB receivers for wireless sensor network applications using massive antenna arrays. Two receivers are proposed: based on instantaneous received UWB signal energy and based on weighted instantaneous received UWB signal energy. The proposed receivers use the law of large numbers resulting from the massive receiver arrays and utilize the large degrees of freedom available in a UWB multipath channel. Furthermore, the proposed receivers do not require training symbols for the estimation of decision threshold. Both these receivers outperform the existing noncoherent receivers as verified using simulation results on the standardized IEEE 802.15.4a UWB multipath channel.

Modeling and Identification of Ultra-Wideband Analog Multipliers

Analog multipliers are employed in many applications. In conventional RF front ends, for example, they are widely used for frequency conversion tasks. In noncoherent energy detectors or autocorrelation receivers, they multiply the (broadband) input signal by itself to achieve a down-conversion. Unfortunately, there exist no ideal hardware realizations of such devices, hence multipliers inevitably create undesired signal content at their output. To be able to deal with these effects or correct for them, we need to be able to model and identify realistic RF multipliers. This paper proposes and validates a multiple-input single-output Wiener–Hammerstein model for ultra-wideband (UWB) analog multipliers. The structure of the proposed model gives insight in the distortions created. It thus provides the possibility to study the realistic behavior of systems involving those multipliers, e.g., the influence of undesired nonlinear signal content onto noncoherent UWB receivers. A comparison of the model performance is shown with respect to measurements and circuit simulations.

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

This paper presents a high linearity and low power Low-Noise Amplifier (LNA) for Ultra-Wideband (UWB) receivers based on CHRT 0.18[Formula: see text][Formula: see text]m Complementary Metal-Oxide-Semiconductor (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 12.8[Formula: see text]dB. The input and output reflection coefficients both are lower than [Formula: see text][Formula: see text]dB over 2.5–11.5[Formula: see text]GHz. The input third-order intercept point (IIP3) is 5.6[Formula: see text]dBm at 8[Formula: see text]GHz and the noise figure (NF) is lower than 4.0[Formula: see text]dB. The LNA consumes 5.4[Formula: see text]mW power under a 1[Formula: see text]V supply voltage.

UWB pulse detection and TOA estimation using GLRT

In this paper, a novel statistical approach is presented for time-of-arrival (TOA) estimation based on first path (FP) pulse detection using a sub-Nyquist sampling ultra-wide band (UWB) receiver. The TOA measurement accuracy, which cannot be improved by averaging of the received signal, can be enhanced by the statistical processing of a number of TOA measurements. The TOA statistics are modeled and analyzed for a UWB receiver using threshold crossing detection of a pulse signal with noise. The detection and estimation scheme based on the Generalized Likelihood Ratio Test (GLRT) detector, which captures the full statistical information of the measurement data, is shown to achieve accurate TOA estimation and allows for a trade-off between the threshold level, the noise level, the amplitude and the arrival time of the first path pulse, and the accuracy of the obtained final TOA.

A Novel Compact Ultra-Wideband Antenna with Quad Notched Bands Based on S-SCRLHs Resonator

In this paper, a novel compact ultra-wideband (UWB) antenna with a quad band-notched function using S-SCRLHs (splited simplified composite right/left-handed) resonator is presented. The S-SCRLHs resonator, which exhibits quadruple resonance, is realized by coupling double S-SCRLH resonator. Then, the S-SCRLHs resonator is integrated into a UWB antenna consisting of modified circular patch. The proposed UWB antenna operates under the frequency range of 3.0–10.7 GHz. This proposed antenna displays a VSWR < 2(the voltage standing wave ratio) across the entire UWB band and compact dimensions of 25 × 20 mm2, which is 0.2λ (free space) at 3.0 GHz. By changing the dimension of S-SCRLHs resonator, the notched frequencies can be adjusted appropriately in four bands of 3.6–3.8 GHz (WiMAX), 4.5–4.9 GHz (C-band), 5.6–6.0 GHz (WLAN), and 7.2–7.6 GHz (X-band). The antenna can be applicable in the UWB receiver systems where the four kinds of interference signals corresponding to the four bands can be suppressed. The gain varies from 2.1 to 4.5 dBi with gain values of −2.8, −2.6, −1.5 and −2.4 dBi at respective four notch frequencies. The radiation efficiency is no less than 84% throughout the operational bandwidth. The proposed antenna achieves omnidirectional radiation patterns while also providing rejection at desired notches.

Design and Implementation of a Digital Secure Code-Shifted Reference UWB Transmitter and Receiver

This paper presents the first compact hardware implementation of a digital code-shifted reference (CSR) ultra-wideband (UWB) transceiver. The security of the transmission is based on changing the physical properties of the transmission without the use of higher level security options. The software models of the designed transceiver are simulated and verified in both floating-point and fixed-point numerical representations. The synthesizable Verilog description of the transceiver architecture is simulated and verified against its fixed-point simulation model. The secure transceiver is implemented on our custom-developed field-programmable gate array (FPGA) board. The characteristic and implementation results of the secure transceiver architecture on the FPGA are presented. The bit error rate performance of the transceiver is measured in real time on the FPGA using an accurate on-chip Gaussian noise generator and is compared with that of the software simulation model. An ASIC architecture of the CSR-UWB transceiver is estimated to occupy 0.019 mm2 and dissipate 0.63 mW from a 1.0 V supply while operating at 82 MHz in a standard 32-nm CMOS technology.

A 1.9-mm-Precision 20-GHz Direct-Sampling Receiver Using Time-Extension Method for Indoor Localization

This paper presents an impulse-radio ultra-wideband (IR-UWB) receiver design for precise wireless ranging using a newly proposed direct sampling with time-extension (DTE) method. To overcome the problems encountered in high-speed sampling for impulse signals, the DTE method, which exploits the characteristics of an impulse, is proposed. The proposed method performs high-speed sampling only during the period when short pulses exist, and quantizes the sampled signal during the dead time where no pulses exist. The high-speed impulse signal can be easily digitized using low-speed analog-to-digital converter. We designed and fabricated the IR-UWB receiver using a 65-nm CMOS process. The measurement result shows a 1.9-mm resolution for indoor wireless ranging within a 1-m range. The receiver has a power consumption of 70 mW at 1.2 V and energy efficiency of 1554 nJ/pulse.

Ultra-wideband receiver technology development for radio astronomical large aperture telescope

Xinjiang 110 m radio telescope (QiTai Telescope, QTT) will play an important role in the field of fundamental science, such as gravitational wave detection, black holes, star formation and galaxy origin, and also be applied to deep space explorations, for example, Lunar Exploration Program and Exploration of Mars and Venus. However, many ultra-wideband, multi-beam receivers will be applied for various science goals of QTT, and we will be faced with numerous significant challenges. In this paper, we have presented the technical progress of ultra-wideband receiver for large aperture telescope, including the ultra-wideband feeds/Ortho-Mode Transducer (OMT), Low Noise Amplifier (LNA) and multi-beam receiver. Meanwhile, key techniques and challenges were analyzed for receiver research and fabrication. Based on the science requirements and the technique development, we have proposed the preliminary scheme for QTT receiver system, and discussed about the feed forms, primary devices research and key coming difficulties and challenges.

A Self-Biased Mixer in $0.18\mu \text{m}$ CMOS for an Ultra-Wideband Receiver

A self-biased CMOS analog mixer for ultra-wideband (UWB) applications is presented in this paper. The proposed mixer is complementary and self-biased, and has lower power consumption, superior isolation, and larger bandwidth. The proposed low-power, down conversion mixer is designed and fabricated in UMC $0.18\mu \text{m}$ CMOS technology. The measurement results show that it can operate at UWB frequencies that range from 1 to 6 GHz. The proposed mixer provides a maximum conversion gain of 13 dB, −4.5 dBm of third-order input intercept point, and a minimum double sideband noise figure of 12 dB. The maximum values of the measured local oscillator LO-to-RF, RF-to-IF, and LO-to-IF isolations are 50, 45, and 52 dB, respectively.

Frequency-Hopping Pulse Position Modulation Ultrawideband Receiver

Pulse position modulation (PPM) has been used in the radio-frequency (RF) domain to achieve both low-dissipation requirements and provide precision ranging. In ultrawideband (UWB) architectures, it underpins an asynchronous receiver, multiple access environments, and interference-resistant transmission. When combined with frequency hopping (FH), it allows for an additional level of immunity to jamming and low probability of intercept. Realization of a FH-PPM transceiver poses a practical challenge, particularly in the UWB RF range. With UWB pulses reaching the multi-gigahertz range, FH adds to the effective bandwidth at which the receiver must be operated, exceeding the performance of a modern quantizer and digital demodulation backplane. This study describes a new photonics-assisted FH-PPM receiver architecture that rests on mutually coherent frequency combs. The performance of the new receiver was characterized by receiving and decoding an 80–Mb/s rate FH-PPM UWB signal.

An Active 20-MHz to 2.5-GHz UWB Receiver Antenna System Using a TEM Horn

An ultrawideband receiver antenna system is proposed. The radiating element is a transverse electromagnetic horn antenna, featuring a negative impedance converter at lower frequencies. The voltage standing-wave ratio (VSWR) is less than 2.0 in the bandwidth from 20 MHz to 2.5 GHz. A good agreement between the measurements of the fabricated system and the simulated results is observed. Sample applications include direction finding, broadband communication systems, radar systems, and electromagnetic compatibility measurement systems.

A parameter estimation algorithm for LFM/BPSK hybrid modulated signal intercepted by Nyquist folding receiver.

Nyquist folding receiver (NYFR) is a novel ultra-wideband receiver architecture which can realize wideband receiving with a small amount of equipment. Linear frequency modulated/binary phase shift keying (LFM/BPSK) hybrid modulated signal is a novel kind of low probability interception signal with wide bandwidth. The NYFR is an effective architecture to intercept the LFM/BPSK signal and the LFM/BPSK signal intercepted by the NYFR will add the local oscillator modulation. A parameter estimation algorithm for the NYFR output signal is proposed. According to the NYFR prior information, the chirp singular value ratio spectrum is proposed to estimate the chirp rate. Then, based on the output self-characteristic, matching component function is designed to estimate Nyquist zone (NZ) index. Finally, matching code and subspace method are employed to estimate the phase change points and code length. Compared with the existing methods, the proposed algorithm has a better performance. It also has no need to construct a multi-channel structure, which means the computational complexity for the NZ index estimation is small. The simulation results demonstrate the efficacy of the proposed algorithm.

Design of a Broadband HEMT Mixer for UWB Applications

Background/Objectives: Microwave mixer is a crucial element in virtually all transmits and receives systems. Methods/Statistical analysis: In this paper, a novel distributed HEMT mixer with three layers is designed for Ultrawide-Band (UWB) receivers. We employ external capacitors in the proposed circuit to adjust the output phase shift between stages to equal the input phase shift. Findings: The simulation results show that the proposed structure, achieves vary broadband performances in Converstion Gain, Power Consumption and LO-RF Isolation, comparable to the recent reported cascode or dual-gate distributed mixers. With a local oscillator power of 12 dBm and RF power of -20 dBm, our mixer has a Conversion Gain of 0 ~ 4 dB (without IF signal amplification), LO-to-RF isolation better than 32 dB and 130 mW DC power consumption over bandwith 5-25 GHz. Applications/Improvements: In our scheme, an intermediate layer is considered to increase LO-RF Isolation and improve the Converstion Gain criterion. Moreover, Microstrip lines are used to form the artificial gate and drain transmission lines as well as phase equalization of the signal on drain transmission line.