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A combination 95 GHz radar and 270/560 GHz spectrometer is being built as a space instrument prototype for probing plumes and jet phenomena in the solar system. Dubbed GAISR (Gas And Ice Spectrometer/Radar), the instrument's radar will make simultaneous range/Doppler measurements of 0.1–10 mm sized ice and dust particles out to a few km in range, while its tunable spectrometer will detect the abundance...
Analog self-interference mitigation techniques are currently being investigated in a variety of operational settings for In-Band Full-Duplex (IBFD) systems. The significant multipath effects of realistic environments, such as inside buildings, can severely limit performance. The influence of different transceiver parameters on the effectiveness of a four-tap RF canceller using a tapped delay line...
To maximize energy efficiency in communications, particularly wireless communications, it is necessary to minimize power dissipation in all circuitry. This joint minimization is unfortunately not independently achievable. Decisions on the type of signal modulation adopted for use in any particular application can and do put lower limits on achievable circuit power dissipation, and therefore putting...
Over the past twenty years or so there has been much interest in the use of digital pre-distortion techniques for the linearization of RF and microwave power amplifiers. This paper presents a snapshot of the current challenges posed by demands for wider bandwidth and lower power consumption, and some potential solutions.
In this paper a power amplifier (PA) linearization technique is proposed where an RF predistorter (RFPD) is used in conjunction with a linearization amplifier (LA) to achieve a more effective joint pre-distortion and post-distortion linearization. This approach is suitable for use with small cells PAs because its power and cost overhead are scalable with the power range and cost of the PA. To demonstrate...
It is proposed that both digital and analog predistortion (DPD, APD) be used to cancel intermodulation distortion (IMD) in a dual band transmitter. DPD reduces IMDs near the carrier frequencies whereas APD cancels IMDs located at multiples of the carrier frequency separation. It is shown that linearization using memoryless basis waveforms provides cancellation of the dominant IMD modes when the two...
Strategies for reducing the number of basis waveforms used in a Volterra series model for digital predistortion (DPD) of RF power amplifiers (PAs) are proposed. Simple DPD models are generalized so that elemental terms within the Volterra series are grouped together or pruned. It is shown that grouping and pruning produce similar ACLR results when the coefficient estimator notch filters the linear...
The paper reviews our recent experimental work in the area of multi-Gigabit fixed wireless links operating in the high millimeterwave frequency range. An E-band link is employed to transmit up to 6 Gbit/s over a line-of-sight terrestrial distance of 36.7 km using QPSK modulation, and 15 Gbit/s over 15 km using 8QAM. At 240 GHz, up to 64 Gbit/s QPSK are transmitted over a distance of 850 m. The paper...
BPSK-signals reception quality depends on the quality of the signal processing. BPSK-modulated codes reception quality depends on the quality of the correlation functions. RF frontend distortions leads to efficiency of the signal processing degrading. RF frontend non-optimal filtering, noise and dynamic range limiting has significant impact on the signal processing quality. In this research simulation...
SAR development and configuring are laborious and technologically complex challenges. During of the SAR development a particular attention is given to developing of small-sized analog RF devices. Distortions in the SAR analog RF path can lead to a synthesized image destruction. Fault diagnosis based on SAR results is the task of increased difficulty. It's difficult to relate distortions of a radar...
We demonstrate a microwave photonic Interference canceller with a balanced architecture capable of relative-intensity noise suppression. Experimental results show that the system can cancel > 25 dB interference over 200 MHz instantaneous bandwidth and tune over a frequency range of 2–8 GHz.
Here we show a new approach to create a sharp tunable microwave bandstop filter. Using a low Brillouin loss of ∼3 dB, we achieved 20-dB extinction filter over a tunable bandwidth of up to 1 GHz with a central frequency tuning range of 16 GHz.
We report RF-spectrum analysis of optical signals based on cross-phase-modulation in a silicon-rich nitride waveguide. Measurements show a bandwidth of at least 560 GHz for our RF-spectrum analyzer. RF-spectra measurements for pulse trains at rates from ∼ 10 GHz to ∼ 160 GHz are demonstrated.
Many new and exciting avionic sensing and surveillance systems are demanding more and more bandwidth to share data between onboard systems [1]. Most of these systems rely on high speed electrical transmission lines that are heavy, bulky, sensitive to EMI and increasingly unable to cope with the very high bandwidths required for large data handling. Traditional ground based telecommunications have...
We demonstrate a 70 Gbit/s photonic wireless link on a single carrier at 60 GHz using a single polarization. To our knowledge, this is the highest data rate on a single polarization 60 GHz carrier.
This paper provides an overview on recent advances on all-digital transceivers, as a promising approach to the ideal Software-Defined Radio concept. Several techniques and architectural optimizations are discussed to improve the coding efficiency, spectral purity, signal to noise ratio, bandwidth and flexibility.
The focus of this contribution is to review delta-sigma based all-digital transmitters and to discuss issues related to large out-of-band quantization noise and possible coexistence problems. Low-complexity embedded-FIR filters are very interesting to relax the filtering constraints while keeping systems as digital as possible to benefit from the advanced CMOS node integration. In this paper we propose...
A novel concept called analog bandwidth interleaving (ABI) has been recently introduced in order to overcome bandwidth limitations of digital-to-analog converters (DACs) by interleaving the output signals of multiple DACs in the frequency domain. We present for the first time the fundamental interdependencies between bandwidth, sample rate, the number of samples, and the local oscillator frequencies...
In wireless sensor networks, the need for ultra- low power consuming nodes is one of the main motivations for research in such field. Because radio sections in sensor nodes contribute to a large extent to the overall power consumption, the focus of this study is on the RF transceiver. The aim is to reduce the average power consumption which depends significantly on the circuit architecture design,...
This paper presents a novel inductorless transimpedance amplifier (TIA) design using Global Foundaries 0.18-µm CMOS technology suitable for high speed optical communication. A modified-RGC preamplifier stage (M-RGC) is used to lower input impedance through cascode and parallel PMOS transistor techniques for wideband operation. The amplifier stage used common source amplifiers to increase the gain...
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