Drain Efficiency Research Articles

Design of a Broadband High‐Efficiency Power Amplifier Based on a Miniaturized Three‐Coupled Line Structure

ABSTRACTThe extended continuous inverse Class‐GF mode with a large available impedance space is employed in the design of the multioctave power amplifier (PA) presented in this paper. A novel miniaturized three‐coupled line structure is combined with the extended continuous inverse Class‐GF mode to achieve ultra‐wideband high‐efficiency PAs. The novel miniaturized three‐coupled line structure is analyzed in detail to meet the design requirements. To verify the effectiveness of the proposed method, a PA working in 0.7–3.0 GHz with a relative bandwidth of 124.3% is designed and fabricated by using CGH40010F. Measurements demonstrate that the output power is from 39.8 to 42.3 dBm, the drain efficiency is between 63.2% and 73.1%, the power added efficiency is from 60.4% to 71.3%, and the gain is from 9.7 to 12.3 dB. The designed PA achieves wide bandwidth and high efficiency while effectively reducing size to facilitate integration.

Design of Tri‐Band Doherty Power Amplifier Using Phase and Impedance Constrained Optimization

ABSTRACTTo realize the wideband and efficient operation of Doherty power amplifier (DPA) in multi‐band mode, this paper proposes a tri‐band DPA design method based on phase and impedance‐constrained optimization. First, the phases required for impedance transformation networks across multi‐band are determined based on the impedance required when the DPA operates at back‐off power (BOP) and saturation. Then, the impedance judgment method using multiple impedance constraint circles was employed to determine the optimal load impedances. Finally, the phase and impedance constraints at multiple frequencies were used to optimize the carrier and peaking output matching networks. For verification, a tri‐band DPA operating at 1.25−1.35, 1.9−2.1, and 2.75−2.85 GHz was designed and fabricated. Measured results show that, for the above three frequency bands, the drain efficiencies (DEs) at saturation reach 59.0%−61.7%, 59.5%−64.2%, and 52.4%−59.8% with corresponding output power exceeding 43 dBm. For 6 dB BOP, the DEs are 46.1%−54.2%, 50.4%−55.2%, and 44.8%−51.9%. Moreover, good linearity can be achieved after linearization for 20 MHz modulated signals.

31W Linear broadband 3.4 to 4.4 GHZ high power class-j GaN HEMT amplifier

The recent upsurge in wireless communication systems requiring high-power transmitters for numerous applications such as electronic warfare (EW), RADAR, Satellite and optical communications has further underscored the importance of linear broadband high-power Class-J power amplifiers. This paper proposes a 31W linear broadband 3.4 to 4.4 GHz high-power Class-J GaN HEMT(gallium nitride high electron mobility transistor)amplifier. The power amplifier was designed based on Cree's commercially available 10WGaN HEMT power transistor device (CGHV40010F) using Keysight Advanced Design System (ADS) software and simulated. The transistor was biased withadrain supply voltage of 48V at aquiescent drain-to-source current of 0.58A,which makes the power transistor suitable for high voltage transmitter operations and foreclosed the need for voltage upgrade, thereby reducing thecost of operation. The power amplifier (PA) operates from 3.4 to 4.4 GHz with a centre frequency of 3.9 GHz. The PA has an output power of 31W, drain efficiency of 36.3%, power added efficiency of 35.3% and power gain of 12.9 dB at an input power of 32 dBm. The PA small signal gain stood at 10.6 dB at acentre frequency of 3.9 GHz. The PA maintained a peak envelope power of 56.2W at aninput power of 31 dBm at atwo-tone Frequency of 3.895 GHz. The proposed PA will find applications in wireless communications, military and aviation transmitters.

A new design method for distributed Doherty power amplifier

This paper introduces the basic theory of a new type of Distributed Doherty Power Amplifier (DDPA) architecture, which uses a step-by-step current injection method for load modulation to improve the modulation network order of the main amplifier and reduce the impedance conversion ratio, thereby increasing the operating bandwidth. The load modulation trajectory and drain efficiency under single-frequency point and wideband range with 6 dB and 8 dB back-off were analyzed, and the effect of peaking branches output phase on the load modulation trajectory and drain efficiency curve were also analyzed. Finally, a DDPA working at 1.5–2.7 GHz (57.1 % relative bandwidth) was designed using Wolfspeed’s CGH40025 transistor. The physical simulation results show that its saturated output power reaches 47.7–48.8 dBm, the saturated gain is 5.17–8.9 dB, and the saturated drain efficiency is 46.53–61 %. The drain efficiency under 8 dB back-off is 43.5–53.7 %, and the drain efficiency under 6 dB back-off is 58.37 %-67.85 %.

An active two-stage class-J power amplifier design for smart grid’s 5G wireless networks

<span>The wireless communication networks in the smart grid’s advanced metering infrastructure (AMI) applications need 5G technology to support large data transmission efficiently. As the 5G wireless communication network’s overall bandwidth (BW) and efficiency depend on its power amplifier (PA), in this work, a two-stage class-J power amplifier’s design methodology that operates at 3.5 GHz centre frequency by utilizing the CGH40010F model gallium nitride (GaN) transistor is presented. The proposed design methodology involves proper designing of input, output, and interstage matching networks to achieve class-J operation with improved power gain over desired BW using the advanced design system (ADS) electronic design automation (EDA) tool and estimating its integration feasibility through active element-based design approach using the Mentor Graphics EDA tool. The proposed PA provides 54% drain efficiency (D.E), 53% power added efficiency (PAE) with a small signal gain of 27 dB at 3.5 GHz and 41 dBm power output with 21 dB of improved power gain across a BW of around 400 MHz using 28 V power supply into 50 Ω load. By replacing the two-stage PA's passive elements with active elements, its layout size is estimated to be (15.5×29.2) μm2 . The results of the proposed PA exhibit its integration feasibility and suitability for the smart grid’s 5G wireless networks.</span>

Design of a Bandpass Continuous Class‐F Filtering Power Amplifier Based on a Terminated Coupled Lines Structure

ABSTRACTThis paper presents a filtered power amplifier (PA) based on the continuous class‐F mode. This broadband filtering PA employs a terminated coupled line structure, which consists of coupled line segments and four terminations loaded on them for obtaining high efficiency over a wide frequency band. Also, a detailed theoretical analysis and calculation of the proposed termination coupling line structure is given. The filter plays the role of filtering and impedance matching simultaneously, and thus high‐order harmonics of the filtering PA are suppressed. For verification, the proposed PA is designed, fabricated, and measured. The measurement results show that a drain efficiency of 60.5%–69.8%, a gain of more than 10 dB, and an output power of 40.2–42.4 dBm are achieved in the target frequency band.

Design of a Series of Inverse Continuous Modes Power Amplifier Based on Bandpass Filter

ABSTRACTIn this paper, a broadband high‐efficiency power amplifier (PA) with filtering characteristics is proposed. This PA is designed using a series of inverse continuous modes (SICMs) and adds a novel coupled microstrip line filter structure. The terminal of this structure is composed of microstrip lines cascaded to improve the out‐of‐band suppression effect. This filter can achieve low in‐band insertion loss, high passband selectivity, as well as deep stopband rejection performance simultaneously. A PA was designed and implemented using a 10 W GaN HEMT device, verifying its wideband characteristics. The measurement result shows that the 39.6–41.6 dBm output power (Pout), 61.6%–73.7% drain efficiency (DE), and 8.6–10.8 dB gain are achieved at 2.2–2.9 GHz.

A High Efficiency Broadband Gallium Nitride Power Amplifier with Harmonic Control technology

ABSTRACT In order to meet the requirements of high efficiency and broadband for the wireless communication system, a high efficiency and broadband gallium nitride power amplifier (PA) is designed and verified. Using the step-matching structure, its bandwidth has been improved. Furthermore, its input matching network is constructed by connecting several microband lines serially to reduce the matching Q value. Meanwhile, the harmonic control network is designed as the output matching network, which is built by a quarter-wave (λ/4) line open circuit and short circuit microwave lines in parallel. Thus, its drain efficiency (DE)can be improved. This design is simulated and tested at 2.2–3 GHz with the gallium nitride (GaN) process. After measuring, it attains an output power (Pout) of 39.5–41.5 dBm, Gain of 10.5–12.5 dB, DE of 65.1%–78.3% with power added efficiency (PAE) of 64.8%–76.2%.

Class iCGF–1 Mode Power Amplifier for Enhancing the Linearity of the Traditional Continuous Class F–1 Mode

ABSTRACTIn this paper, the iCGF−1 mode is proposed to compensate the amplitude‐to‐amplitude modulation (AM/AM) distortion of the traditional continuous class F−1 mode while maintaining the high efficiency. The AM/AM profile of the iCGF−1 mode is mathematically expressed simultaneously as a function of the input nonlinearity parameter and conduction angle , which makes the iCGF−1 mode more flexible in controlling the AM/AM profile. The first inflection point of the AM/AM profile can be moved to a higher output power level through theoretical deduction by adjusting the second harmonic source impedance and gate bias voltage to increase the values of and . This flattens the AM/AM profile while the efficiency profile remains almost the same as that of the traditional continuous class F−1 mode. The performance of the iCGF−1 mode is verified through simulation and experimental measurements. The iCGF−1 PA is fabricated with CGH40010F and has a frequency range of 2–2.6 GHz. The drain efficiency is 70.1%–77.9%, and the output power is 41.1–41.7 dBm. The linearity is tested with a 100 MHz 5G NR signal (the peak average power ratio (PAPR) is 8.5 dB) at 2.3 GHz. The worst adjacent channel power ratio (ACPR) is −32.3 dBc without digital predistortion (DPD) and −52.1 dBc with DPD. The results show that the iCGF−1 mode has successfully compensated the AM/AM distortion of the traditional continuous class F mode and maintaining high efficiency.

Design and Experimental Validation of a High-Efficiency Sequential Load Modulated Balanced Amplifier

The purpose of this paper is to present a detailed design procedure for a highly efficient sequential load-modulated balanced amplifier (SLMBA) to provide an in-depth analysis of this complex power amplifier (PA) architecture. SLMBA’s basic theory is presented and discussed. An SLMBA with a frequency range from 2.45 GHz to 2.65 GHz was implemented and then measured in order to validate the proposed design methodology. In both saturation and back-off states, the fabricated SLMBA exhibits extremely high efficiency and output power. It delivers a maximum output power of 43~44.4 dBm and a drain efficiency (DE) of 71.6~75% at saturation, a DE of 63.5~66% at 6 dB output back-off (OBO) state, a DE of 61.8~66% at 10 dB OBO state, and a DE of more than 51% at 12 dB OBO state in the targeted frequency band. The achieved results demonstrate the effectiveness of the proposed design procedure.

Design of Broadband Highly Efficient Power Amplifier Based on Low‐Pass Filtering Network With Periodic Structure

ABSTRACTIn this paper, a broadband high‐efficiency power amplifier (PA) is designed by using an easily implementable low‐pass filtering network with periodic structure as the output matching circuit to achieve bandwidth expansion of the PA. The proposed periodic structure is based on right‐handed T‐type basic cells, which can achieve wideband filtering responses. In addition, the load design space of the extended continuous Class‐F mode is combined as the target impedance to achieve an efficiency improvement in bandwidth PAs. For verification, a broadband highly efficient PA across 0.6–3.6 GHz with a relative bandwidth of 143% is designed, fabricated, and measured. The test results have shown a drain efficiency of 60.8%–70.4% and gain of 8.5–11.9 dB with a saturation output power under 3‐dB gain compression of 38.5–41.9 dBm.

Design of highly efficient filtering power amplifier with a wideband response for sub-6 GHz 5G applications

This paper presents the design of a filtering power amplifier (PA) with extra-high power-efficiency and wide bandwidth. To accomplish this, a novel approach is adopted by utilizing a wideband bandpass filter (BPF) as the output matching network (OMN) for the PA. The BPF compromises two paths, where each path consisting of two identical coupled lines that are interconnected to form a ring structure. The suggested configuration eliminates the need for a conventional OMN by integrating the input port of the filter with the drain node of the transistor, resulting in reduced size and losses and improved amplifier performance. The filter concept is illustrated using coupling matrix synthesis. A proof-of-concept filtering PA has been designed using a commercially available 10 W GaN HEMT. This amplifier was designed to operate in the frequency range of 3.0–5.0 GHz, yielding a fractional bandwidth of 50 %. According to achieved results, the drain efficiency and output power are 43.8–70.5 % and 40.2–41.8 dBm, respectively. As a result, the suggested filtering PA demonstrates significant performance in terms of filter bandwidth response and power amplification. Additionally, the proposed filtering PA has a broad operational bandwidth of 3.0–5.0 GHz, which covers the 5G New Radio (NR) n77 (3.3–4.2 GHz), n78 (3.3–3.8 GHz), and n79 (4.4–5.0 GHz) frequency bands.

An enhanced broadband class-J mode power amplifier for 5G smart meter applications.

Background: With the tremendous increase in the usage of smart meters for industrial/ household purposes, their implementation is considered a crucial challenge in the Internet of Things (IoT) world, leading to a demand for emerging 5G technology. In addition, a large amount of data has to be communicated by smart meters efficiently, which needs a significant enhancement in bandwidth. The power amplifier (PA) plays a major role in deciding the efficiency and bandwidth of the entire communication system. Among the various modes of PAs, a newly developed Class-J mode PA has been proven to achieve high efficiency over a wide bandwidth by maintaining linearity. Methods: This paper proposes a Class-J mode PA design methodology using a CGH40010F-GaN device that operates at a 3.5 GHz frequency to meet the requirements of 5G wireless communication technology for the replacement of existing 4G/LTE technology used for advanced metering infrastructure (AMI) in smart grids. This research's main objective is to design the proper matching networks (M.Ns) to achieve Class-J mode operation that satisfies the bandwidth requirements of 5G smart grid applications. With the target impedances obtained using the load-pull simulation, lumped element matching networks are analyzed and designed in 3 ways using the ADS EDA tool. Results: The simulation results reveal that the proposed Class-J PA provides a maximum drain efficiency (D.E) of 82%, power added efficiency (PAE) of 67% with 13 dB small-signal gain at 3.5 GHz, and output power of 40 dBm (41.4 dBm peak) with a power gain of approximately 7 dB over a bandwidth of approximately 400 MHz with a 28 V power supply into a 50 Ω load. Conclusion: The efficiency and bandwidth of the proposed Class-J PA can be enhanced further by fine-tuning the matching network design to make it more suitable for 5G smart meter/grid applications.

Implementation of Electromagnetic Theory: Improved Analysis and Design for Class F Power Amplifier

ABSTRACTThe general electromagnetic (EM) theory has not yet been applied to the analysis of Class F (CF) power amplifier (PA). In this paper, an alternative approach for CF PA is presented based on the EM theory. Theoretical analysis shows that the CF PA can be divided into two broad categories, forward voltage gain, and reflected voltage gain PA. The existing CF PA belongs to the reflected voltage gain PA. Even though both the CF PAs have the same voltage gain, the PA with forward voltage gain provides higher fundamental power Ps,1@F and drain efficiency PAE@F than that CF PA with reflected voltage gain and Class B PA. This important conclusion is obtained as a result of this analysis, which cannot be explained by available theory in the literature. The theoretical analysis is validated at 2.2 GHz by fabrication and measurements. According to the results, Ps,1@B = 31.8 dBm and PAE@B = 53.27% in Class B PA. In CF PA with reflected voltage gain, Ps,1@F = 30.20 dBm and PAE@F = 48.6%. Both cases have lower power and PAE as compared to new category of CF PA. This new CF PA with forward voltage gain has, Ps,1@F = 33.04 dBm and PAE@F = 63.7%.

Complementary split ring resonator-inspired multi-HCN for implementation of an efficiency-enhanced inverse class-F2,3 PA

This article introduces a conceptual framework for enhancing the efficiency of an inverse class-F2,3 (F2,3−1) power amplifier (PA) through the incorporation of an innovative metamaterial-based multi-harmonic control network (multi-HCN). In the recommended approach, the multi-HCN comprises two resonant cells inspired by square-shaped complementary split ring resonator (CSRR), which are configured to suppress unwanted harmonics and to obtain the desired waveforms. The primary focus is to showcase how CSRRs can be effectively employed to form a shunt resonator through the etching of the conductive pattern of the proposed multi-HCN. Apart their harmonic tunability, CSRRs offer various noteworthy attributes such as impressive wave restoration capabilities and the capacity to address spatial limitations. To assess the efficacy of the proposed methodology, a class-F2,3−1 PA is devised and constructed utilizing a commercially available 10 W GaN HEMT device. The presented class F2,3−1 PA yields a commendable drain efficiency (DE) ranging from 50.3 % to 84 % and achieves an output power within the range of 38 dBm to 41.2 dBm across the bandwidth of 3.3 GHz to 3.7 GHz. These significant performance metrics serve as compelling evidence, validating the effectiveness of the proposed approach. Furthermore, this achievement establishes the design as a promising path for creating high-performance, affordable PA suitable for emerging communication systems.

3.3-4.3 GHz efficient continuous class-F gallium nitride power amplifier based on simplified real frequency technique and harmonic tuning.

In order to implement the fifth generation (5G) communication system for a large number of users, the governments of many countries nominated the low 5G frequency band between 3.3 and 4.3 GHz. This paper proposes a wideband RFPA by designing the input matching network (MN) and output MN of the device using the simplified real frequency technique (SRFT) and the harmonic tuning network. The load-pull and source-pull is applied at multiple points for 100 MHz intervals over the bandwidth to obtain the optimum impedances at the output and input of the 10W Gallium Nitride (GaN) Cree CGH40010F device. To verify the design, the RFPA is simulated, and the performance is measured between 3.3 and 4.3 GHz. According to experimental findings, the measured drain efficiency (DE) throughout the whole bandwidth ranged from 57.5 to 67.5% at the output power of 40 dBm. Moreover, at the 1 dB compression point between 39.2 and 42.2 dBm output power, the drain efficiency (DE) achieves a high value of 81.2% with an output power of 42.2 dBm at a frequency of 3.3 GHz. The RFPA can obtain a maximum gain of 12.4 dB at 3.5 GHz. The linearity of the RFPA with a two-tone signal is measured and the value is less than -22 dBc all over the band.

Microwave Power Performance of AlGaN/GaN High‐Electron‐Mobility Transistor on Semi‐Insulating Mn‐Doped GaN Substrate

Herein, a DC and microwave performance of 2 μm gate length AlGaN/GaN high‐electron‐mobility transistor (HEMTs) on a Mn‐doped GaN substrate is demonstrated. The maximum drain current is 670 mA with a threshold voltage of 2.5 V and with good pinch‐off characteristics. The breakdown voltage of the HEMT is ≈80 V. The HEMT shows Δ8% current collapse while referenced HEMT on a SiC substrates which is fabricated simultaneously shows large Δ30% current collapse. When the HEMT with a gate width of 100 μm is tuned for the maximum output power at 2.4 GHz with a drain voltage of 30 V, it delivers 500 mW (5 W mm−1) with the maximum drain efficiency of 54%. These output performances are in good agreement with ideal class‐A operation performance. Therefore, it is concluded that the HEMT on Mn‐doped GaN substrates is promising for future microwave and millimeter‐wave high‐power transistors.

Bandwidth Extension of the Doherty Power Amplifier Using the Impedance Distribution and Control Circuit for the Post-Matching Network

Owing to the high impedance transformation ratio, the Doherty power amplifier (DPA) with a large output power back-off generally has bandwidth limitations. This study proposes an asymmetric DPA with an impedance distribution and control circuit (IDCC) at the post-matching network to improve the bandwidth. The IDCC, based on a resonance circuit and a series transmission line, distributes and controls the load impedance according to the frequency so that the bandwidth of the DPA can be extended. To verify the proposed IDCC, an asymmetric DPA was designed using GaN HEMT with a power capacity of 6 W and 10 W for the carrier and peaking amplifiers, respectively. The implemented DPA was evaluated for the broad frequency band between 3.3 GHz and 3.8 GHz using a 5G new radio (NR) signal with a bandwidth of 100 MHz and a peak-to-average power ratio of 7.8 dB. A drain efficiency between 43.2% and 50.7% and an adjacent channel leakage power ratio between –23.4 dBc and –27.3 dBc were achieved at an average power level that ranged between 33.5 dBm and 34.3 dBm.

Inverse Class‐E power amplifier with broadband capability at different switch‐off duty ratio

AbstractThe paper explores the investigation of an inverse Class‐E amplifier featuring a series output filter across various switch‐off duty ratios D. Analysis of different duty ratios as a design parameter reveals their impact on peak switch voltage, output power capability, and maximum operating frequency. Notably, it is demonstrated that adjusting the D ratio affects these parameters, with specific emphasis on achieving a maximum normalized switch voltage lower than 2 and an output power capability exceeding 0.1 for D = 0.7. Furthermore, the paper considers both parasitic shunt capacitance and series inductor in the load network, a departure from previous works that solely focused on the series inductor. The proposed circuit is highlighted for its ease of implementation compared with conventional reactance compensation circuits employing parallel resonant circuits, which are challenging to form directly. An innovative approach is introduced to showcase the broadband performance of the inverse Class‐E amplifier. The measured drain efficiency and output power versus input power at 430 MHz are 82% and 45.3 dBm, respectively. A similar performance can be achieved within the frequency range of 380–600 MHz by proper tuning at saturated power. The measurement results demonstrate a maximum high power‐added efficiency (PAE) of 79% and drain efficiency of 82% within this frequency range, accompanied by a gain exceeding 12.0 dB and output power surpassing 44 dBm.

Design of a broadband high-efficiency power amplifier based on a rectangular double transmission line structure

Abstract This paper presents a design methodology for a broadband high-efficiency power amplifier (PA). The large available impedance space of the extended continuous Class-GF mode is employed. A novel output matching network of the PA consisting of a rectangular double transmission line structure is proposed to meet impedance requirements. To validate the effectiveness of this structure, a high-efficiency PA operating in 0.8–3.0 GHz is designed using a CGH40010F GaN transistor. The measured results demonstrate that the drain efficiency falls within the range of 63.2%–71.9%, the output power varies from 40.2 to 42.2 dBm, and the gain ranges from 9.4 to 11.3 dB within the frequency band of 0.8–3 GHz. The realized PA exhibits an extremely competitive relative bandwidth of 115.8%.