An LDMOS VHF class-E power amplifier using a high-Q novel variable inductor

In this paper, an lateral diffused metal-oxide-semiconductor-based very high-frequency class-E power amplifier has been investigated theoretically and experimentally. Simulations were verified by amplifier measurements and a record-high class-E output power was obtained at 144 MHz, which is in excellent agreement with simulations. The key of the results is the use of efficient device models, simulation tools, and the invention of a novel high-Q inductor for the output series resonance network. The latter allows for low losses in the output network and, simultaneously, a wide tuning range for maximum output power or maximum efficiency optimization

Targeting MYC and exploring the role of mitochondrial metabolism in childhood neuroblastoma

MYCN is a member of the MYC family of proto-oncogenes, encoding transcription factors (c-MYC, MYCN and L-MYC) that play crucial roles for normal cellular functions and during development. However, the expression of MYC (here referring to c-MYC and MYCN) is found elevated in a large number of human cancers where it is implicated in most aspects of tumorigenesis and correlates to poor clinical outcome. Neuroblastoma is a heterogenous childhood cancer of the sympathetic nervous system. Tumors harboring amplification of the MYCN gene are highly aggressive and these patients have a poor prognosis. Consequently, new treatments directed against high MYC expressing tumors could help to improve the survival rates of these children. In Paper I, we screened 80 chemotherapeutic drugs and small chemical compounds to assess their selectivity against MYC-overexpression, using cancer cells with conditional c-MYC or MYCN expression. Positive hits belonged to distinct classes of chemical agents acting on selective cellular processes, including RNA, DNA and protein synthesis and turnover, and those inhibiting microtubules and topoisomerases. These results may provide indications for future drug development and treatment optimization towards MYC. One important goal in cancer research is to identify small molecules, which can interfere with MYC’s function, since today, no therapeutically relevant therapy acting directly against MYC exists. In Paper II we demonstrated that a previously identified c-MYC binding molecule, 10058-F4, showed selectivity towards high MYCN expressing neuroblastoma cells and resulted in prolonged survival in a MYCN-driven transgenic mouse model of neuroblastoma. In Paper IV, we further demonstrated that 10058-F4 and a few additional c-MYC-binding small molecules bind directly to the corresponding region of MYCN, and that their binding affinities correlated with the level of growth suppression in cells. Metabolic rewiring is an important feature in aggressive tumors. In Paper II we showed that downregulation of MYCN in neuroblastoma cells leads to accumulation of cytoplasmic lipid droplets caused by mitochondrial dysfunction. In this regard, MYCN was found to be linked with an overall elevated mitochondrial metabolism important for mediating tumor aggressiveness in neuroblastoma. In Paper III, we carried out a systematic investigation of metabolic alterations associated with MYCN in neuroblastoma, using patient gene expression data, quantitative proteomics and functional studies of metabolic pathway fluxes. MYCN was found to positively regulate glycolysis, respiration as well as oxidation of exogenous fatty acids in neuroblastoma cells, suggesting that MYCN mediates metabolic plasticity, which could account for an important survival mechanism during neuroblastoma tumor progression. Together the work comprised in this thesis support the development of targeted therapy against MYCN and identified MYCN-induced metabolic signals as a potential approach to target high risk neuroblastoma

C-Band Resistive SiC-MESFET mixer

In this paper the design and characterization of a linear C-band single ended resistive SiC-MESFET mixer is presented. The mixer has a minimum conversion loss of 7.8 dB and has a third order intermodulation intercept point of 30.3 dBm. The mixer is designed using a harmonic-balance simula-tion load-pull approach. This design method is especially use-ful for high-level mixers, where small-signal approximations cannot be used

Calculation of the Performance of Communication Systems from Measured Oscillator Phase Noise

Oscillator phase noise (PN) is one of the major problems that affect the performance of communication systems. In this paper, a direct connection between oscillator measurements, in terms of measured single-side band PN spectrum, and the optimal communication system performance, in terms of the resulting error vector magnitude (EVM) due to PN, is mathematically derived and analyzed. First, a statistical model of the PN, considering the effect of white and colored noise sources, is derived. Then, we utilize this model to derive the modified Bayesian Cramer-Rao bound on PN estimation, and use it to find an EVM bound for the system performance. Based on our analysis, it is found that the influence from different noise regions strongly depends on the communication bandwidth, i.e., the symbol rate. For high symbol rate communication systems, cumulative PN that appears near carrier is of relatively low importance compared to the white PN far from carrier. Our results also show that 1/f^3 noise is more predictable compared to 1/f^2 noise and in a fair comparison it affects the performance less.Comment: Accepted in IEEE Transactions on Circuits and Systems-I: Regular Paper

A QFN packaged grid array antenna in low dielectric constant LTCC for D-band applications

International audienceA medium-gain Grid Array Antenna (GAA) is developed and manufactured in ESL41110, a low εr Low Temperature Co-fired Ceramics (LTCC) from ElectroScience Laboratory. The antenna dimensions are 12 mm × 12 mm × 0.3 mm and it has a measured impedance bandwidth from 135 to 142 GHz, with a boresight maximum gain of 7.96 dBi and vertical beams. In order to realize this antenna, new LTCC fabrication steps had to be developed and qualified in the in-house procedure, including laser ablation of gold in the green state as well as after sintering

High linear power amplifier for multicarrier satellite communications

High linearity performance in transmitters is receiving continuously attention due to demands of higher data rates in satellite communication links. This paper presents a GaAs pHEMT MMIC high linear power amplifier intended for multicarrier operation at C-band. Junction temperature prediction methods are considered during the amplifier design to keep the temperature under control and achieve high reliability required for space applications. The design method is focused in high linearity optimizing the loads and using a non-linear transistor model to predict harmonic generation and intermodulation products. The amplifier was characterized in terms of S-parameters, single tone output power and two tone output power. The measured S-parameters shows a flattened gain over 25 dB between 3 and 6 GHz. The 1dB compression point is measured at 26.7 dBm and the output third order intercept point (OIP3) is above 40 dBm in the band reaching a maximum of 41.7 dBm at 4.5 GHz. The power consumption is lower than 2.5 W and the junction temperatures are calculated under 105 \ub0C

A low noise 2-20 GHz feedback MMIC-amplifier

A low noise feedback MMIC-amplifier based on a 180 GHz f(max) PHEMT-technology is described. The gain input and output reflection coefficient, de-power consumption, and noise parameters are investigated theoretically and experimentally as a function of dc-bias and frequency. The noise figure is typically 2.5 dB with an associate gain of 22 dB across the 2-20 GHz frequency range. The circuit area is less than 1 mum(2) and the de-power consumption is lower than 100 mW

InP DHBT Single-Stage and Multiplicative Distributed Amplifiers for Ultra-Wideband Amplification

This paper highlights the gain-bandwidth merit of the single stage distributed amplifier (SSDA) and its derivative multiplicative amplifier topologies (i.e. the cascaded SSDA (C-SSDA) and the matrix SSDA (M-SSDA)), for ultra-wideband amplification. Two new monolithic microwave integrated circuit (MMIC) amplifiers are presented: an SSDA MMIC with 7.1dB average gain and 200GHz bandwidth; and the world's first M-SSDA, which has a 12dB average gain and 170GHz bandwidth. Both amplifiers are based on an Indium Phosphide DHBT process with 250nm emitter width. To the authors best knowledge, the SSDA has the widest bandwidth for any single stage amplifier reported to date. Furthermore, the three tier M-SSDA has the highest bandwidth and gain-bandwidth product for any matrix amplifier reported to date

A Direct Carrier I/Q Modulator for High-Speed Communication at D-Band Using 130 nm SiGe BiCMOS Technology

This paper presents a 110-170 GHz direct conversion I/Q modulator realized in 130 nm SiGe BiCMOS technology with ft/fmax values of 250 GHz/ 370 GHz. The design is based on double-balanced Gilbert mixer cells with on-chip quadrature LO phase shifter and RF balun. In single-sideband operation, the modulator exhibits up to 9.5 dB conversion gain and has measured 3 dB IF bandwidth of 12 GHz. The measured image rejection ratio and LO to RF isolation are as high as 20 dB and 31 dB respectively. Meas-ured input P1dB is -17 dBm at 127 GHz output. The DC power con-sumption is 53 mW. The active chip area is 620 μm× 480 μm in-cluding the RF and LO baluns. The circuit is capable of transmit-ting more than 12 Gbit/s QPSK signal

An ultrawideband microwave medical diagnostic system: Design considerations and system performance

We discuss several issues in the design of an ultra-wideband microwave system dedicated to medical diagnostics. Based on the discussion, a FPGA-based time domain microwave diagnostic system is proposed. The noise sources of the system are identified and the system noise performance is analyzed. As an example, a 2-D antenna system is considered and the measurement signal to noise ratios are evaluated