A weighted averaging scheme with flip angle adaptation is presented for segmented 2D-selective RF excitations and applied to single-line segments of a blipped-planar trajectory. Segments covering the central k-space, i.e. those with significant signal contributions, are averaged more often than the (outer) segments with low RF amplitudes and minor signal contributions. For compensation, these o...

In this paper, we study spectrum sensing based on dimensionality reduction and random forest (RF) in low signal-to-noise ratio environments. Classifications of three digital modulation types, including BPSK, OFDM and 2FSK, are investigated. From the received radio signal, a set of cyclic spectrum features are first calculated, and the principal component analysis (PCA) is applied to extract the...

This paper introduces a new concept in RF MEMS switches intended for high RF signal power applications at millimetre-wave operation. The novel SPST switch architecture employs electrothermal hydraulic microactuators. Out-of-plane silicon levers, having spring action and latching mechanisms, have been designed to create an OFF-state gap separation distance of 250 μm between ohmic contact electro...

Nowadays, it is easy to find radio transceivers having small size, low cost and still offering numerous functionalities. High-integration of radio-frequency (RF) circuits is still the main trend in the development of wireless devices. A down-converter is an essential part of any RF receiver. It basically performs the frequency translation between an incoming RF signal into a lower frequency to ...

Abstract The proposed Next Linear Collider (NLC) contains linac systems operating at L,S,C, and X band. This paper describes a wideband modular low-level RF (LLRF) system applicable for all NLC pulsed RF systems. High speed digital IF techniques are used for both arbitrary klystron drive modulation and accurate RF vector detection. Measurement of relative beam to RF phase, beam loading compensa...

Low power wireless sensor networks provide a new monitoring and control capability for civil and military applications in transportation, manufacturing, biomedical, environmental management, and safety and security systems. Wireless microsensor network nodes, operating at average and peak power levels constrained by compact power sources, offer a range of important challenges for low power meth...

background: the electrocardiogram artifact is a major contamination in the electromyogram signals when electromyogram signal is recorded from upper trunk muscles and because of that the contaminated electromyogram is not useful. objective: removing electrocardiogram contamination from electromyogram signals. methods: in this paper, the clean electromyogram signal, electrocardiogram artifact and...