The high-frequency power amplifier (RF PA) plays a central role in every transmission and reception chain. Such amplifiers are not only used in classic applications such as mobile communications, aerospace and defence, but also in medical technology – especially in magnetic resonance imaging (MRI).
In MRI systems, a powerful RF pulse is emitted at the so-called Larmor frequency – i.e. the frequency at which the hydrogen nuclei (protons) precess in the static magnetic field. In a 3-Tesla MRI system, this frequency is approximately 128 MHz. The RF pulse excites the spins of the protons. When they return to their ground state, the protons emit energy in the form of RF signals, which are measured and used for image reconstruction.
The high-frequency power amplifier (RF PA) plays a central role in every transmission and reception chain. Such amplifiers are not only used in classic applications such as mobile communications, aerospace and defence, but also in medical technology – especially in magnetic resonance imaging (MRI).
In MRI systems, a powerful RF pulse is emitted at the so-called Larmor frequency – i.e. the frequency at which the hydrogen nuclei (protons) precess in the static magnetic field. In a 3-Tesla MRI system, this frequency is approximately 128 MHz. The RF pulse excites the spins of the protons. When they return to their ground state, the protons emit energy in the form of RF signals, which are measured and used for image reconstruction.
The high-frequency power amplifier (RF PA) plays a central role in every transmission and reception chain. Such amplifiers are not only used in classic applications such as mobile communications, aerospace and defence, but also in medical technology – especially in magnetic resonance imaging (MRI).
In MRI systems, a powerful RF pulse is emitted at the so-called Larmor frequency – i.e. the frequency at which the hydrogen nuclei (protons) precess in the static magnetic field. In a 3-Tesla MRI system, this frequency is approximately 128 MHz. The RF pulse excites the spins of the protons. When they return to their ground state, the protons emit energy in the form of RF signals, which are measured and used for image reconstruction.
Superparamagnetic iron-oxide nanoparticles (SPIONs), composed of a magnetic iron-oxide core and a tunable non-magnetic coating, exhibit rapid magnetic response along with exceptional stability and biocompatibility [1], [2]. These characteristics have fostered their applications in diverse medical fields including drug delivery [3], diagnostic imaging [4], and hyperthermia therapy [5].
The characteristics of nanoparticles are closely related to their structure. Their structure is well layered. Crystals, iron oxide nuclei, aggregates, clusters and agglomeration are gradually formed as the scale increases. The formation of these different hierarchical structures determines the macroscopic properties of the final nanoparticle.
Description
With future generations of mobile communications and ultra-high-resolution radar applications in mind, integrated circuits are being developed for frequency ranges above 100 GHz. In this frequency range, distributed structures (large dimensions relative to the wavelength) are often pref...
Description
Jamming of wireless data transmission is considered a form of Denial of Service (DoS) attack and poses a threat to modern communication systems. In order to initiate suitable countermeasures against a jamming attacks at an early stage and thus protect the communication system, it is imp...
In order to integrate AI algorithms, e.g. in the form of neural networks, into wireless communications systems, it is necessary to drastically reduce their resource consumption with regard to an embedded implementation. This begins with the selection of a suitable model architecture and often involves well-known optimization methods such as quantization and pruning.
Radio Frequency (RF) Fingerprinting offers the potential for rapid authentication of communication partners in future wireless communication systems. Potential application areas include mobile communications and radar applications. Other hardware-based methods, such as Physically Unclonable Functions (PUF), are related to RF Fingerprinting.
