A multimode/multiband envelope tracking (ET) transmitter consisting of a hybrid switching amplifier (HSA) and broadband saturated power (PA) is developed for operation across 1.3 to 2.7 GHz. For the various standard signals with different bandwidth (BW) peak-to-average ratio, HSA efficiently provides supply PA by changing reference value hysteresis comparator. The employs nonlinear output capacitor shape voltage waveform, resulting in half-sinusoidal or rectangular waveform. Since generates...

A power amplifier (PA) for a femto-cell base station should be highly efficient and small. The efficiency amplification of high peak-to-average ratio (PAPR) signal is improved by designing an asymmetric Doherty (DPA). From the simulation result long-term evolution (LTE) with 7.2-dB PAPR, DPA delivers highest 1:1.4 cell size carrier peaking PAs. small achieved using GaN monolithic microwave integrated circuit process. For broadband operation, we employ new topology to alleviate bandwidth...

An asymmetric Doherty Power Amplifier (ADPA) is introduced using a new output combining circuit for easy of implementation with large matching tolerance. The proposed APDA has been implemented GaN HEMT devices at 2.6 GHz WiMAX signal 5MHz bandwidth and 8.3 dB peak to average power ratio. This ADPA delivers saturated 51.7 dBm drain efficiency 60.4% an 43.6 dBm. After linearization digital feedback predistortion technique, the satisfies linearity specification -51.98 dBc adjacent channel...

Accurate offset line design of Doherty amplifier is investigated to compensate the phase variation carrier and peaking amplifiers. The at not only blocks power leakage OFF-state, but also assists in load modulation like amplifier. However, with conventional line, properly modulated due class C Since lines amplifiers (PAs) eliminate reactive parts during modulation, can handle also. To variation, additional are added for proper modulation. With new be efficiency high region increased. In...

Due to the complexity of innovation process and intensifying competition, small medium enterprises (SMEs) have increased their participation in public-private networks (PPINs). This study used both inference prediction models by linking two heterogeneous databases (DBs), consisting responses 1,439 manufacturing SMEs Korean Innovation Survey financial information approximately 119,890 companies. In model, we analyzed determinants that affect business performance R&D investment PPINs, using...

In this article, a high-efficiency saturated amplifier has been presented. This takes advantage of the nonlinear output capacitor to shape voltage waveform. The generates substantial second harmonic with small higher order harmonics. Thus, using √2 times larger fundamental load and proper termination, resultant waveform can be half-sinusoidal. For high efficiency, PA should driven by large input power. Therefore, current is bifurcated, resulting in quasirectangular shape. waveforms are...

This paper presents an approach to maximize the gain and power-added efficiency (PAE) of a Doherty power amplifier (PA) using 0.25 μm GaN pHEMT. The conventional carrier PA has input matching for R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">OPT</sub> load does not deliver 3 dB higher with 2R due mismatch it degrades PAE PA. To solve problem, match is optimized at back-off level output load, while mismatched high level. A concept designed...

This letter presents an approach to maximize the output power and efficiency of a Doherty amplifier (PA). The conventional carrier PA having 2R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">OPT</sub> match, used in symmetric PA, does not deliver saturated high at 6 dB back-off but 5.5 due knee voltage effect. To solve problem, gate biases peaking PAs are adapted. bias is optimized for higher peak power, delivering 3 larger R match. That also...

A highly efficient CMOS saturated power amplifier (PA) is implemented. The efficiency enhanced by the voltage waveform engineering using second harmonic component generated nonlinear output capacitor (C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">out</sub> ). For an improved linearity to satisfy specification of handset applications, a simple open-loop digital predisortion algorithm employed. fully integrated single-stage differential PA...

A power amplifier (PA) for a femto-cell base station should be highly efficient, linear and small. The efficiency amplification of high peak-to-average ratio (PAPR) signal is improved by designing an asymmetric Doherty PA (DPA). linearity applying third-order inter-modulation (IM3) cancellation method. For dual-band operation, tunable switched capacitor applied. small size achieved the DPA using GaN MMIC process. implemented delivers DE 45.5/41.6%, ACLR −35.6/−34.5 dBc, gain 15.7/13.2 dB...

Covers advancements in spacecraft and tactical strategic missile systems, including subsystem design application, mission analysis, materials structures, developments space sciences, processing manufacturing, operations, applications of technologies to other fields.

Demand-side innovation policies have recently been playing a significant role in solving contemporary challenges, especially the energy sector. They facilitate introduction and diffusion of mature technologies with low technical risk market, thereby creating demand for centered on technologies. It has potential to induce lock-ins technologies, which may cause long-term problems. This study investigates how demand-side differently influence performance between competing different...

An average power tracking (APT) Doherty amplifier (PA) is analyzed in terms of its biasing voltage condition, efficiency, and output power. And the drain gate bias voltages are optimized for operation at different conditions. The designed using 45 W gallium nitride (GaN) high electron mobility transistors (HEMT) carrier peaking cells 1.94 GHz. controlled each level(42.9 dBm, 39.9 37 dBm). measured efficiencies gains 53.2%, 12.8 dB 42.9 dBm 54.3%, 11.2 53.4%, 9.1 a 10 MHz LTE signal with 6.5...

The Doherty power amplifier has the most attractive architecture to improve efficiency for amplifying a signal with high peak‐to‐average ratio. However, ideal operation is difficult be achieved because g m of peaking should two times larger than that carrier amplifier. mismatch between and amplifiers hinders proper load modulation at peak region. an auxiliary drive cell introduced solve problem. drives main higher input power, solving gain output reduction Experimental results show proposed...

The effect of the peaking offset line on Doherty amplifier operation is investigated. structure operates at a C-bias condition for load modulation. With C-bias, has poor AM-PM characteristic due to nonlinear input/output capacitances. phase variation influences modulation behavior and reduces efficiency high output power region. To mitigate PM amplifier, length should be reduced from conventional line. validate design, 2-stage implemented 2.655 GHz using GaN pHEMT. Due proper modulation, PA...

This work proposes a new offset line of carrier PA for Doherty power amplifier (PA). The conventional (DPA) delivers lower efficiency at back-off output than peak due to the phase mismatch in implementation, because is very sensitive impedance change. To solve problem, adopted optimizing performance power, while it maintains power. A with concept designed using 45 W gallium nitride (GaN) high electron mobility transistors (HEMT) and peaking cells 1.94 GHz. measured average drain/power-added...

A power amplifier (PA) for a femto-cell base station should be highly efficient, linear and small. The efficiency amplification of high peak-to-average ratio (PAPR) signal was improved by designing an asymmetric Doherty PA (DPA). linearity applying third-order inter-modulation (IM3) cancellation method. small size is achieved the DPA using GaN MMIC process. implemented 2-stage delivers power-added (PAE) 38.6% gain 33.4 dB with average 34.2 dBm 7.2 PAPR 10 MHz bandwidth LTE at 2.14 GHz.

A quarter-wavelength transformer, phase compensation network, offset line are the bandwidth limiting factors of Doherty PAs. In this paper, we expand PA by employing a new structure. The conventional network is merged into an input matching circuit and resonated-out inductor. quarter wavelength transformer has low-Q characteristic compared to that one. With proposed topology, broadband implemented using TriQuint 3MI 0.25μm GaN-HEMT MMIC process. Across 2.1-2.7 GHz, delivered DE over 40.5%,...

An optimized peaking amplifier for proper operation of a Doherty is investigated. The operates at class-C bias and has lower maximum output power than that the carrier amplifier. Because low amplifier, load modulation network cannot be properly carried out. To solve problem, an inductive second harmonic employed input. conduction angle input voltage waveform enlarged due to out-of-phased harmonic, restoring decreased power. In addition, turns on higher first peak efficiency enhanced. Based...

In many industrial processes and operations, such as power plants, petrochemical industries ships, shell tube heat exchangers are widely used probably applicable for a wide range of operating temperatures. The main purpose exchanger is to transfer between two or more medium with temperature differences. Heat highly nonlinear, time-varying show time lag behavior during operation. control has been challenging engineers variety forms PID controllers have proposed guarantee better performance....

A multimode/multiband envelope tracking (ET) transmitter consisting of a hybrid switching amplifier (HSA) and broadband saturated power (PA) is developed across 1.3 to 2.7 GHz. For the various standard signals with different bandwidth peak-to-average ratio, HSA efficiently provides supply signal PA by changing reference value hysteresis comparator. The PA, taking advantage nonlinear output capacitor shape voltage waveform, implemented based on load/source-pull methodology. Broadband matching...