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This paper discusses the design of wideband Doherty amplifier. Design strategy basically depends upon the elimination of bandwidth constraints in basic Doherty amplifier as pointed by the investigation, which are quarter wave impedance transformer and capacitance at the transistor output terminal. In this frame work, high efficiency can be achieved by designing wideband Doherty power amplifier which...
The power amplifier is becoming most challenging modules to design in a wireless communication system. Also, a wireless communication is demanding multi-band transmitter and receiver, so the design to get optimum efficiency and linearity in power amplifiers in multi-band applications becomes more and more challenging day by day. As such, a lot of work has been performed to design highly efficient...
This paper presents the new design of distributed amplifier (DA) with control mechanism to enhance the efficiency performance by tuning the impedance at the gate termination adjustment network and applying drain line tapering topology. This distributed power amplifier (DPA) system is design based on the GaN high electron mobility (HEMT) transistor and simulated by using Advanced System Design tool...
The popular use of biomedical implants has been going on in numerous applications that include the use of pacemakers and emerging retina prostheses, together with brain-computer interfaces. Other popular uses include drug delivery and smart orthopaedic implants. The avoidance of batteries or piercing wirings has made the wireless powering of these implantable devices highly attractive. In this paper,...
In this paper, a wideband Doherty power amplifier along with a novel design strategy for peaking output matching network is presented. The proposed matching network is designed by maintaining a predetermined electrical length to eliminate the using of peaking offset line for expanding the bandwidth effectively and improving the back-off efficiency. For higher than 50% efficiency at 6 dB back-off power,...
In this contribution a gallium nitride (GaN) based inverse class F (F−1) power amplifier with in situ waveform measurement capability is presented. Which the measurement approach the high frequency time domain voltages and currents in a reference plane can be measured directly in the circuit. Therefore, a directional coupler is integrated in the output matching network of the F−1 power amplifier....
Minimizing size, weight, and power consumption (SWaP) in any communication system requires that the transmitter power amplifier operate at peak possible efficiency at all times and at all frequencies. Here a GaN watt-level transmitter is presented that operates across 0.2 to 3 GHz, with no matching network reconfiguration, and broadband efficiency exceeding 50%. Besides minimizing power consumption,...
The balance operation between the efficiency and the linearity of RF power amplifier is the greatest challenging factor in wireless communication system. Amplifier is the most energy consuming element in a system, where more than 50% of the power produce is converted to heat energy as a waste. This situation gradually affects other devices in the transmitter system and can result to system performance...
In this paper, a comparison between the concurrent multi-band and parallel single-band power amplifier architectures is analyzed. A generalized framework in which these two architectures can be compared in terms of cost, drain efficiency, output power, and linearity is developed. Results show that in general, a concurrent multi-band power amplifier will have worse performance than a parallel single-band...
Customer demands for battery powered portable electronic devices have increased. Today high data rates could be transmitted using fourth generation Long-Term Evolution (4G LTE) wireless communications standard. To increase system runtime proper envelope amplifier's architecture has to be selected. Using envelope tracking technique efficiency of the transmitter's power amplifier (PA) can be improved...
A novel load-pull based outphasing combiner synthesis approach is developed. The design technique is based on the derivation of combiner network parameters in terms of the optimal load impedances at the peak power level and a predefined back-off level. The combiner is then synthesized using transmission lines or lumped element networks. The design technique is verified in a 30 W GaN HEMT outphasing...
In this paper, a 60 GHz power amplifier is presented in 65nm CMOS technology based on the transformerless load-modulated (TLLM) amplifier architecture. It is designed to obtain high efficiency at output power back-off. The amplifier has 12.5 dB small signal gain and 11.5 dBm saturated output power. Measurement results show that this amplifier has more than 8% drain efficiency (7% power-added efficiency)...
This paper presents a high efficiency Gallium Nitride (GaN) class-F power amplifier (PA) which uses a Chebyshev bandpass filter to realize the optimal fundamental and harmonic impedance matching. The bandpass output matching network also absorbs the output parasitics of the power amplifier. A prototype PA is implemented to verify this idea, which delivers output power of 37.5 dBm with peak power added...
A new class of S/C Band Miniature Traveling Wave Tubes (TWTs) is being developed for a microwave power module and aero plane that can be used for radar applications. The maximum dimensions of the S/C miniature TWTs, which saturated output is greater than 200 W (53 dBm), and efficiency greater than 30% and harmonic-ratio less than −3dBc, were just 300mm×80mm×40mm.
This paper describes the development of a Ka-band Helix Travelling Wave Tube (TWT) for Millimeter wave Power Modules (MMPM). Measurements show that the TWT is capable to deliver output power of more than 100W with a high overall efficiency of 50% over 2 GHz bandwidth in Ka-band under the condition of equal input power. The TWT also has a compact package size of 280mm(L)×60mm(W)×40mm(H) with a light...
In this paper, we report a two-way sequential power amplifier (SPA) using GaN HEMTs. The proposed fully analog SPA delivers Psat of approximately 40dBm over 2–3 GHz covering 40% fractional bandwidth. The design consists of a 3dB input coupler, a main amplifier, a peak amplifier, and a 10dB output coupler for power combining. After proper designing and optimizing these critical wideband couplers in...
This paper reports the first high power LDMOS amplifier solution which breaks the 50% drain efficiency barrier at 8 dB output back-off (OBO) for 2.1 GHz cellular application. Targeted for fourth-generation (4G) LTE communication systems, the work seeks to achieve high average efficiency when used with OFDM or other high peak-to-average ratio (PAR) digitally modulated signals. A power transistor, the...
this paper presents a new closed form expression for the average efficiency of power amplifiers (PA) driven by modulated signals. Based on an approximation for the PA I-V curve, the PA output power and the DC current are estimated using the probability distribution function (PDF) of the modulated signal. The efficiency as a function of transistor parameters and the bias point is estimated. The closed...
Power Amplifier (PA) is a very important component in communication systems which consume a significant fraction of the total energy and is mostly nonlinear. There is an inverse relationship between the PA efficiency and its linearity. Nonlinear PAs are desirable from an efficiency point of view. The price paid for higher efficiency is that it causes growth in spectrum and causes adjacent channel...
In this paper, a dual-band outphasing transmitter (able of operating either at 770 MHz or 960 MHz frequency bands) is presented. Two broadband RF power amplifiers (PAs) have been designed over packaged GaN HEMT devices, switching close to the nominal zero-voltage and zero-voltage-derivative class E conditions. A reactive combiner, using transmission lines of appropriate electrical lengths at both...
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