Linear Transfer Characteristics Research Articles

Study of Lithium Biodistribution and Nephrotoxicity in Skin Melanoma Mice Model: The First Step towards Implementing Lithium Neutron Capture Therapy.

Boron neutron capture therapy (BNCT) is one of the promising treatment methods for malignant melanoma. The main issue of this technology is the insufficient selectivity of 10B accumulation in tumor cells. As a result of the neutron absorption by boron, an 84% energy release occurred within the cell by the nuclear reaction 10B (n, α)7Li, which lead to tumor cell death. The use of lithium instead of boron brings a new unique opportunity-local 100% energy release-since all products of the 6Li (n, α)3H reaction have high linear energy transfer characteristics. The aim of this study was to determine the concentrations of Li in the tumor, skin, blood, brain and kidney in experimental animals with B16 melanoma and to analyze the potential Li toxicity after lithium carbonate administration at single doses of 300 and 400 mg/kg. Lithium carbonate was chosen since there is a long-term experience of its use in clinical practice for the treatment of psychiatric disorders. The inductively coupled plasma atomic emission spectrometry was used to evaluate Li concentrations in tissue samples. The accumulation efficiency of Li in the tumor was the highest at a time point of 30 min (22.4 µg/g; at a dose of 400 mg/kg). Despite the high lithium accumulation in the kidneys, the pathological changes in kidney tissues were not found. Thus, lithium may actually be used for the Li-NCT development and future studies can be conducted using 6Li and following irradiation of tumor cells using the schemes of lithium administration tested in this work.

Simplified Digitizing Interface-Architectures for Three-Wire Connected Resistive Sensors: Design and Comprehensive Evaluation

This article describes the design, analysis, and performance verification of simple digitizing interfaces for different types of three-wire resistive sensors. The proposed interface uses an efficient resistance-to-time conversion technique that charges an internal capacitor, between two reference levels, through selected resistive-sensor paths. A simple analog circuit controlled using a digital timing unit realizes the aforementioned technique. This approach is adaptable for various resistive sensor configurations and does not depend on the effect of connecting wire resistances and various other non-ideal parameters (e.g., threshold voltage and pin resistance of microcontroller, offset voltage of comparator, etc.). In addition, the proposed schemes utilize its digital unit (e.g., microcontroller) only for control and timing operations, thus saving on power. The detailed working principle of the proposed interfaces and their error analysis are discussed in the article. Later, performance verification is carried out using simulation as well as emulation studies. These studies clearly show that the presented digitizing interfaces provide linear digital transfer characteristics with maximum nonlinearity of 0.17% and wire resistance compensation. Further, tests are conducted with various remotely located commercial sensors. The outcomes of these studies are reported and compared with the state-of-the-art works.

Design, Analysis, and Hardware Verification of a Linearized Thermistor-Based Temperature Measurement System

This article brings forward a thermistor-based system for linear estimation of temperature. The proposed system uses a relaxation oscillator-based digitizer and a versatile linearization approach as the core elements in its architecture. This linearizing digitizer for thermistors, aided with ratiometric operations, provides many salient features, including: 1) simplicity of system architecture; 2) direct-digital linear transfer characteristics; 3) compensation against connecting lead resistances; 4) low calibration requirements; and 5) wide range of operation, with better performance with respect to the prior art. The design philosophy of the proposed system is mathematically derived and presented in this article, and the aforementioned features are theoretically established. Furthermore, detailed error analysis, as well as experimental evaluation of the hardware system prototype, is carried out. The developed digitizer is shown to exhibit excellent performance (nonlinearity < 0.09%, relative error < 0.4%, and lead resistance influence < 0.1%) during emulation studies, over a range of 0 °C – 120 °C. Multiple exper- iments with synthesized thermistor characteristics and actual sensor interfacing tests reveal that the maximum output nonlinearity of the developed system is around 0.45%. This article also discusses precision-wise performance and allied use cases of the system, followed by a summary of its comparison study with similar literature.

A fast simulation method for analysis of SEE in VLSI

The transistor simulation tools (e.g. TCAD and SPICE) are widely used to simulate single event effects (SEE) in industry. However, due to the variances of the physical parameters in practical design, e.g. the nature of the particle, linear energy transfer and circuit characteristics would have a large impacts on the final simulation accuracy, which will significantly increase the complexity and cost in the workflow of the transistor level simulation for large scale circuits. Therefore, a new SEE simulation scheme is proposed to offer a fast and cost-efficient method to evaluate and compare the performance of large scale circuits in the effects of radiation particles. In this work, we have combined both the advantages of transistor and hardware description language (HDL) simulations, and proposed accurate SEE digital error models for high-speed error analysis in the large scale circuits. The experimental results show that the proposed scheme is able to handle SEE simulations for more than 40 different circuits with the sizes varied from 100 transistors to 100 k transistors.

Evidence of 2D intersubband scattering in thin film fully depleted silicon-on-insulator transistors operating at 4.2 K

We report the observation at low temperature of a hump in the linear transfer characteristic of a thin film fully depleted silicon-on-insulator transistor when a positive bias is applied on the back gate under the buried oxide. This decrease in the current is correlated with the transition from one-subband to two-subband conduction. Electron mobility measurements and calculations are in good agreement with the occurrence of intersubband scattering in carrier transport in the two-dimensional inversion layer.

Two-terminal wide range SQUID amplifier with hysteretic quasi linear transfer characteristics

To implement wide range measurement using direct current Superconducting Quantum Interference Device (dc SQUID), we presented a simple two-terminal SQUID amplifier consists of a shunt resistor and a conventional SQUID in series with feedback coil. Only two terminals are led out with coaxial cable for high speed and low heat loss. Periodically repeated quasi linear flux-to-voltage transfer characteristics are achieved by internal flux feedback. Wide range flux input is modulated by the SQUID amplifier into voltage signal with rapid transient edges. The reconstructed output is the synthesis of measured voltage and counts of flux-quanta counting. Working principles of linearized SQUID amplifier were simulated and experimentally verified. Wide range measurement with error within ±0.1Φ0 was demonstrated in the experiment.

Silicon Photonic Modulator Linearity and Optimization for Microwave Photonic Links

We experimentally demonstrate the influence of the DC Kerr effect in silicon photonic Mach-Zehnder modulators (MZMs) and the ability to optimize the combined effects of plasma-dispersion and DC Kerr to achieve linear transfer characteristics and thus demonstrate suitability for microwave photonic links and digital modulation formats such as multilevel pulse amplitude modulation. PN and PiN doped modulators were fabricated through AIM Photonics. Intermodulation distortion products are demonstrated to have reverse bias and MZM bias dependencies advantageous for highly linear operation. The spurious-free dynamic range, gain, and noise figure are optimized by choice of phase modulator reverse bias and MZM bias point yielding analog links with spurious-free dynamic ranges greater than 100 dB·Hz2/3. The silicon modulators demonstrate link spurious-free dynamic ranges on par with a commercial lithium niobate modulator. Furthermore, we show that simulations including the DC Kerr effect can reliably predict device performance although direct prediction of analog link metrics remains challenging, and final tuning of the device operating conditions is required to achieve optimum performance.

Abstract 3729: Heavy-ion space radiation exposure is a potential risk factor for gastrointestinal tumorigenesis even at extremely low doses

Abstract Heavy-ion radiation (HZE)-induced carcinogenesis is a major concern in astronauts planning to undertake long-term deep space exploration, such as a mission to the Mars. Due to high-LET (linear energy transfer) characteristics of HZE ions present in deep space environment, the Mars mission is expected to substantially enhance gastrointestinal cancer risk in astronauts, relative to low-LET radiation. Previously, using three different mouse models of human colorectal cancer (APCmin/+, APC1638N/+ and IL10-/- mouse) we have unequivocally demonstrated a significantly higher risk of intestinal and colonic tumorigenesis after exposure to energetic heavy ions. This study aims to obtain quantitative GI-tumorigenesis data at space relevant doses (5-50 cGy) of heavy ions covering a broad-spectrum of linear energy transfer (2-148 keV/μm), relative to γ-radiation. The APC1638N/+ mouse was used due to its best signal-to-noise ratio among all previously studied mouse models of human gastrointestinal cancer. Both female and male APC1638N/+ mice (6-8 weeks, n=20) were whole-body exposed to sham-radiation, γ-rays, 4He (2 keV/μm), 12C (13 keV/μm), 16O (22 keV/μm), 28Si (69 keV/μm), and 56Fe (148 keV/μm) -ion radiation at 5, 10, and 50 cGy dose at the NASA Space Radiation Laboratory (NSRL) in Brookhaven National Laboratory. Mice were euthanized at 150 d after radiation exposure and intestinal and colon tumor frequency and size were scored and analyzed as a function of dose, LET, and gender. The highest increase in tumor frequency was observed after 28Si followed by 56Fe, 16O, 12C, and 4He radiation, and male preponderance for tumorigenesis was evident for each radiation type and dose. At 50 cGy dose, no significant difference in tumorigenesis was observed between γ and 4He. However, at lower doses (5 and 10 cGy) significantly higher tumorigenesis was noted after 4He exposure. Furthermore, calculation of relative biological effectiveness (RBE) for tumorigenesis showed the highest value with 28Si and lower doses showed greater RBE relative to higher doses. No statistical difference in tumorigenesis pattern was evident between 16O and 12C at all studied doses. In addition no significant change in tumorigenesis pattern was evident between 28Si and 56Fe in female mice. Analysis showed greater tumorigenesis per unit of radiation (per cGy) at lower doses suggesting radiation-induced tumorigenesis reaching a saturation point at higher doses. The lack of understanding on radiation quality effects is one of the major uncertainties in space radiation exposure-associated cancer risk prediction. Using a broad-spectrum of HZE-ions we have demonstrated the dependence of gastrointestinal tumorigenesis on radiation quality even at very low doses, which has implications in cancer risk prediction for astronauts and also for accessing secondary cancer risks after particle radiotherapy. Citation Format: Shubhankar Suman, Santosh Kumar, Bo-Hyun Moon, Jerry Angdisen, Bhaskar VS Kallakury, Albert J. Fornace, Kamal Datta. Heavy-ion space radiation exposure is a potential risk factor for gastrointestinal tumorigenesis even at extremely low doses [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3729.

Abstract 3736: Space radiation-induced decline in gut autophagy and expansion of both mitotic and senescent population denotes an aging phenotype with enhanced cancer risk

Abstract Exposure to space radiation is known to alter a myriad of cellular processes that could potentially affect astronauts’ health during and after long duration’s space missions. Due to high-LET (linear energy transfer) characteristics of energetic heavy ions (HZE) present in space, astronauts are predicted to be at higher risk for gastrointestinal cancer development. Proliferative epithelial cells in gastrointestinal (GI) tissue are highly radiosensitive and in our previous studies we have demonstrated a persistent stress phenotype in crypt cells after heavy ion space radiation exposure. However, uncertainty remains in our understanding of how heavy ions induce chronic stress and inflammation is linked to higher cancer risk. The purpose of the current study was to assess late effects of heavy ion (56-Fe) on the autophagy process that is required to recycle damaged cellular components and its role in HZE-induced gastrointestinal carcinogenesis. C57BL6/J mice were exposed to 1.6 Gy of 56-Fe radiation at NASA Space Radiation Laboratory (NSRL). Mice were euthanized 2-month after radiation and intestinal tissues were analyzed for oxidative stress and associated DNA damage, and alterations in antioxidant response and autophagy signaling. Further, cells underdoing mitosis, autophagy and stress-induced senescence were also scored and alterations in cell signaling pathways with established role in carcinogenesis were evaluated. Energetic heavy ions exposure resulted in a long-term increase in intracellular reactive oxygen species (ROS), accompanied with decreased expression of key antioxidant genes (Gpx, SOD and catalase). Increase in both mitochondrial and cytosolic ROS was evident as both loss of mitochondrial membrane potential (MMP) and increase in prooxidant Nox1 expression was found. Paradoxical increases in phospho-histone-3 positive (mitotic) and p16 positive (senescent) cells were found, however decreases in autophagy positive (LC3B) cells was noted in HZE-exposed mouse intestine. Upregulation of upstream mTOR-PI3K-AKT signaling and p62 were noticed in long-term suppression of autophagy (Atg12, LC3B and Beclin-1) after HZE-exposure. Here, we show that space radiation downregulated autophagy processes, which are an important cellular mechanism involved in suppression of carcinogenesis. When considered along with upregulation of proliferative pathways and increased oxidative stress, our data suggest increased risk of chronic GI diseases including cancer due to late persistence of damaged organelles in cells after energetic heavy ion radiation exposures. Collectively, this study demonstrates a unique phenomenon of heavy ion-induced suppression of autophagy concurrent with increases in both mitotic and senescent cells indicating a premature aging phenotype with enhanced cancer risk. Citation Format: Kamal Datta, Shubhankar Suman, Bo-Hyun Moon, Albert J. Fornace. Space radiation-induced decline in gut autophagy and expansion of both mitotic and senescent population denotes an aging phenotype with enhanced cancer risk [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3736.

Hyperthermia with photon radiotherapy is thermoradiobiologically analogous to neutrons for tumors without enhanced normal tissue toxicity

The depth dose profiles of photons mirror those of fast neutrons. However, in contrast to the high linear energy transfer (LET) characteristics of neutrons; photons exhibit low LET features. Hyperthermia (HT) inhibits the repair of radiation-induced DNA damage and is cytotoxic to the radioresistant hypoxic tumor cells. Thus, thermoradiobiologically, HT simulates high LET radiation with photons. At temperatures of 39–45 °C, the physiological vasodilation allows rapid heat dissipation from normal tissues. On the contrary, the chaotic and relatively rigid tumor vasculature results in heat retention leading to higher intratumoural temperatures. Consequently, the high LET attributes of HT with photon radiations are mostly limited to the confines of the heated tumor while the normothermic normal tissues would be irradiated with low LET photons. HT thereby augments photon therapy by conferring therapeutic advantages of high LET radiations to the tumors akin to neutrons, while the ‘heat-sink’ effect spares the normal tissues from thermal radiosensitization. Thus, photon thermoradiotherapy imparts radiobiological advantages selectively to tumors analogous to neutrons without exaggerating normal tissue morbidities. The later has been the major concern with clinical fast neutron beam therapy. Outcomes reported from several clinical trials in diverse tumor sites add testimony to the enhanced therapeutic efficacy of photon thermoradiotherapy.

An Analysis of the Highly Linear Transfer Characteristics of Dual-Buck Converters

Practical switching devices have finite turn-on and turn-off times. To avoid short circuit, a blanking time is added between turn-off and turn-on of the complementary working switches in a switching-leg. The blanking time, also referred to as deadtime, is one of the dominant sources of output current and voltage distortion in pulse-width modulated (PWM) power amplifiers. Extensive studies exist on elimination, minimization, and compensation of the effect. Most techniques achieve a reduction of the distortion but are not capable of completely removing it. The dual-buck (DB) converter does not suffer from blanking-time-related distortion. However, blanking time is not the only source of switching-leg-induced distortion. This paper focuses on the effects of semiconductor device parameters on the output quality of the DB converter. It is shown that, ideally, the forward voltages of the diodes and switches have no effect on the output quality. Measurements on a prototype, industrial power stack based, DB converter show a 100 times improvement of the open-loop spurious free dynamic range when compared to conventional PWM converters.

Real-time digital signal recovery for a multi-pole low-pass transfer function system.

In order to solve the problems of waveform distortion and signal delay by many physical and electrical systems with multi-pole linear low-pass transfer characteristics, a simple digital-signal-processing (DSP)-based method of real-time recovery of the original source waveform from the distorted output waveform is proposed. A mathematical analysis on the convolution kernel representation of the single-pole low-pass transfer function shows that the original source waveform can be accurately recovered in real time using a particular moving average algorithm applied on the input stream of the distorted waveform, which can also significantly reduce the overall delay time constant. This method is generalized for multi-pole low-pass systems and has noise characteristics of the inverse of the low-pass filter characteristics. This method can be applied to most sensors and amplifiers operating close to their frequency response limits to improve the overall performance of data acquisition systems and digital feedback control systems.

Design and performance evaluation of two novel linearisation circuits for giant magneto‐resistance based sensors

This study presents two simple and efficient linearisation circuits for giant magneto-resistance (GMR)-based magnetic field sensors. GMR sensors are commonly available in wheatstone-bridge form, comprising two active GMR and two passive GMR elements. The output of such a sensor possesses a non-linear dependence on the input magnetic field. The proposed linearisation circuits operate on the output of a GMR sensor and provide a linear output with respect to the magnetic field. The first GMR linearisation circuit (GLC1) is based on an enhanced feedback compensation approach, while the second (GLC2) scheme uses a constant current technique. The methodologies of the schemes are described using mathematical derivations. Detailed analyses of the schemes are carried out to bring out the effects of circuit and sensor non-idealities on circuit performance. Further, the circuits were implemented on printed circuit boards and tested. Test results showed the capability of GLC1 and GLC2 to produce linear transfer characteristics. A prototype GMR sensor unit was then fabricated and tested with the developed circuits. Output non-linearity obtained during the experimentation was around 0.7%. Analyses of the results proved the superior performance of GLC1 and GLC2 over the existing schemes.

Low and high dose rate heavy ion radiation-induced intestinal and colonic tumorigenesis in APC1638N/+ mice

Ionizing radiation (IR) is a recognized risk factor for colorectal cancer (CRC) and astronauts undertaking long duration space missions are expected to receive IR doses in excess of permissible limits with implications for colorectal carcinogenesis. Exposure to IR in outer space occurs at low doses and dose rates, and energetic heavy ions due to their high linear energy transfer (high-LET) characteristics remain a major concern for CRC risk in astronauts. Previously, we have demonstrated that intestinal tumorigenesis in a mouse model (APC1638N/+) of human colorectal cancer was significantly higher after exposure to high dose rate energetic heavy ions relative to low-LET γ radiation. The purpose of the current study was to compare intestinal tumorigenesis in APC1638N/+ mice after exposure to energetic heavy ions at high (50cGy/min) and relatively low (0.33cGy/min) dose rate. Male and female mice (6–8 weeks old) were exposed to either 10 or 50cGy of 28Si (energy: 300MeV/n; LET: 70keV/μm) or 56Fe (energy: 1000MeV/n; LET: 148keV/μm) ions at NASA Space Radiation Laboratory in Brookhaven National Laboratory. Mice (n=20 mice/group) were euthanized and intestinal and colon tumor frequency and size were counted 150days after radiation exposure. Intestinal tumorigenesis in male mice exposed to 56Fe was similar for high and low dose rate exposures. Although male mice showed a decreasing trend at low dose rate relative to high dose rate exposures, the differences in tumor frequency between the two types of exposures were not statistically significant after 28Si radiation. In female mice, intestinal tumor frequency was similar for both radiation type and dose rates tested. In both male and female mice intestinal tumor size was not different after high and low dose rate radiation exposures. Colon tumor frequency in male and female mice after high and low dose rate energetic heavy ions was also not significantly different. In conclusion, intestinal and colonic tumor frequency and size was similar irrespective of energetic heavy ion radiation dose rate suggesting that carcinogenic potential of energetic heavy ions is independent of dose rate.

Physical SPICE Model of Organic Thin Film Transistor

Electronic devices operate through charge carrier injection and transport, which are strongly dependent to the electronic structure of the semiconductor. For disordered organic semiconductors, Gaussian density-of-states (Gaussian DOS) and hopping transport are often proposed, described by analytical expressions for the charge carrier mobility as a function of the charge carrier density, electric field and temperature. However, due to the mathematical complexity of this approach, device level modelling is still lacking. In particular, for OFETs, correlation between charge carrier mobility and field-effect mobility is not sufficiently understood. We proposed an analytical model, easy adaptable to spice model, for the linear regime transfer characteristics of OFETs with power-law dependent μ and RC. The ratio method provides a set of parameters that give good match between transfer characteristics from experiment and model. This work has been funded by Horizon 2020 Marie Skłodowska-Curie Research and Innovation Staff Exchange (RISE) Program (2015–2019) entitled DOMINO.

Threshold voltage extraction techniques adaptable from sub‐micron CMOS to large‐area oxide TFT technologies

SummaryThis paper proposed simple and accurate threshold voltage (VTH) extraction techniques, which can be directly adaptable to various semiconductor technologies ranging from deep sub‐micron complementary metal–oxide–semiconductor to large‐area thin‐film transistor devices. These techniques are developed using multiple circuits, namely, a dynamic source follower, an inverter with a diode‐connected load and a current mirror topology, which allow a direct determination of VTH. As the proposed techniques are experimented with large‐area emerging technologies, which have a stable single type (n‐type) transistor, all the designs employed in this work are confined to only n‐type transistors for a fair comparison. The semiconductor technologies under consideration are standard complementary metal–oxide–semiconductor (65 and 130 nm) and oxide (indium–gallium–zinc–oxide and zinc–tin–oxide) thin‐film transistors. In order to validate the accuracy of the proposed techniques, extracted VTH from these methods are compared against the value from linear transfer characteristics. The resulting relative error is within 5%, reinforcing proposed techniques suitability to different semiconductor technologies ranging from deep sub‐micron to large‐area transistors. Copyright © 2017 John Wiley &amp; Sons, Ltd.

Space radiation exposure persistently increased leptin and IGF1 in serum and activated leptin-IGF1 signaling axis in mouse intestine.

Travel into outer space is fraught with risk of exposure to energetic heavy ion radiation such as 56Fe ions, which due to its high linear energy transfer (high-LET) characteristics deposits higher energy per unit volume of tissue traversed and thus more damaging to cells relative to low-LET radiation such as γ rays. However, estimates of human health risk from energetic heavy ion exposure are hampered due to lack of tissue specific in vivo molecular data. We investigated long-term effects of 56Fe radiation on adipokines and insulin-like growth factor 1 (IGF1) signaling axis in mouse intestine and colon. Six- to eight-week-old C57BL/6J mice were exposed to 1.6 Gy of 56Fe ions. Serum and tissues were collected up to twelve months post-irradiation. Serum was analyzed for leptin, adiponectin, IGF1, and IGF binding protein 3. Receptor expressions and downstream signaling pathway alterations were studied in tissues. Irradiation increased leptin and IGF1 levels in serum, and IGF1R and leptin receptor expression in tissues. When considered along with upregulated Jak2/Stat3 pathways and cell proliferation, our data supports the notion that space radiation exposure is a risk to endocrine alterations with implications for chronic pathophysiologic changes in gastrointestinal tract.

Dual-stage, Time-over-Threshold based prototype readout ASIC for silicon microstrip sensors

This paper presents the architecture details and measurement results of the prototype multichannel ASIC implementing a dual-stage charge sensitive processing chain based on a Time-over-Threshold technique. The readout front-end electronics is equipped with pulsed reset and it is dedicated for input charge measurements in semiconductor detector systems with sensor capacitances of few tens of pF. The presented solution reduces impact of important problems in the Time-over-Threshold charge processing chains, like pile-up effects and excessive dead time in case of artifact hits׳ overload. The key features of the presented solution are: low power consumption (2.5mW/channel), charge and time measurements with linear transfer characteristic (INL=1.8%), large dynamic range (>10fC) and linear transfer characteristics of Time-over-Threshold processing.

Conduction Mechanism in SrTiO&lt;sub&gt;3&lt;/sub&gt;-Based Field-Effect Transistors

In this brief, we find that the previously reported performance improvement of HfO2/SrTiO3 devices after argon bombardment may be attributed to the decrease of interface traps. With the greatly reduced interface trap density, the HfO2/SrTiO3 device after argon bombardment shows remarkable reduction of turn-ON voltage shift with decreasing temperature, which is in contrast with the unbombarded HfO2/SrTiO3 device. Though HfO2/SrTiO3 devices behave like conventional transistors, Al2O3/SrTiO3 devices show very different linear transfer characteristics, which may be due to the high density of shallow donor states near the Al2O3/SrTiO3 interface. The exhibited SrTiO3-based device characteristics are studied by experiments and simulations. The simulations with drift-diffusion model reproduce the experimental results.

Output Power and Loading of Superconducting Quantum Array

Using numerical simulation, we investigate the output power and loading tradeoffs for Superconducting Quantum Arrays (SQAs) suggested for the implementation of broadband radio-frequency systems, including active electrically small antennas capable of providing highly linear transfer characteristics with a high dynamic range. Standard matching loads used for linear microwave networks, including passive antennas, are not applicable for the active SQA-based circuits generally due to the strong shunting effect restricting the attainable linearity. At the same time, the output power of an active device can be increased by a power supply even for the impedance-mismatched circuits. Both the optimum achievable balance of the shunt effects and getting the required output power are analyzed and discussed in detail.