Multi-octave Power Amplifier Research Articles

Design and optimization of spoof surface plasmon polaritons based multi-octave power amplifier using PSO algorithm

In this article, we explore how spoof surface plasmon polaritons (SSPP) theory can be applied to the design of active radio frequency (RF) power amplifiers (PAs). This work utilizes SSPP structures for the design of both input and output matching networks for a multi-octave PA. In order to perform proper impedance matching, the properties of SSPP unit structures are presented and analyzed. A description of the performance of the initial PA has been provided and discussed. Additionally, particle swarm optimization (PSO) is used to further enhance the performance of the PA circuit. In comparison with an embedded gradient method in a commercial tool, the PSO method results in a better optimization result. The fabricated PA is tested and the results indicate that in the frequency range of 0.5 GHz to 2.9 GHz, it achieves an output power of 40.4 dBm to 41.2 dBm, a power added efficiency of 60.5–65%, and an output gain exceeding 10 dB. Compared to recent work, the multi-octave PA in this work broadens bandwidth while maintaining high output power and PAE. To further verify the linearity of the SSPP-based PA, digital pre-distortion (DPD) is implemented. As a result of the DPD, the linearity of the SSPP PA was greatly enhanced.

Design of a 0.4–3.9-GHz Wideband High-Efficiency Power Amplifier Based on a Novel Bandwidth Extended Matching Network

The design of a multi-octave power amplifier (PA) is presented based on extended continuous Class-B/J (ECB/J) modes in this paper. The wide design space provided by the ECB/J modes has been used as the goal for the design. A unique bandwidth extended matching network that can achieve a broadband impedance matching in the appropriate impedance region by simultaneously manipulating six frequency points is proposed to compensate for the impedance dispersion effect caused by the change of the optimal impedance with the operating frequency in the design of the matching network. To verify the proposed methodology, a wideband PA is designed and fabricated by using a commercial 10-W gallium nitride (GaN) device. The implemented PA achieves a bandwidth of 163% from 0.4 to 3.9 GHz while exhibiting excellent performance of 38-42.3 dBm output power, 57-68% drain efficiency, and 10-13 dB gain. The measured adjacent channel power ratio (ACPR) is lower than -26 dBc at 0.8, 1.5, 2.0, 2.5, 3.0, and 3.5 GHz when the output power is lower than 36 dBm.

Extending the Design Space of Class E Mode to Design a Multi-Octave Power Amplifier

This brief presents a new extended continuum of class E (ECCE) mode for multi-octave power amplifier (PA) design. The impedance space of class E mode is expanded by considering the resistive component in the second harmonic impedance. This provides an overlap between the fundamental and second harmonic loads, which is for the first time explored for class E mode, enabling its design beyond the octave band. This mode offers a wide impedance range for the third harmonic termination, unlike a fixed point (open/short) in other extended continuous modes. This wide third harmonic design space provides high flexibility to design output matching. To verify the validity of the proposed mode, a PA has been designed using a 10W GaN HEMT CGH40010F from Wolfspeed. A design scheme is also presented to obtain the feasible matching loads at desired frequencies. The PA operates over a multi-octave band from 0.45-2.9 GHz, corresponding to the fractional bandwidth of 146.27%. This circuit provides drain efficiency of 60-72.9% and the output power between 39.6-41.7 dBm over the operating band.

Design of a multi-octave power amplifier with a novel broadband design methodology

Design of a multi-octave power amplifier with a novel broadband design methodology

A Complexity-Reduced Harmonic-Cancellation Digital Predistortion for HF Transmitters

High-frequency (HF) transmitter implemented with the multioctave power amplifier (PA) is faced with the problem of high-order harmonics owing to the nonlinearity of the PA. In this letter, a complexity-reduced harmonic-cancellation digital predistortion (CR-HC-DPD) is proposed and a narrow pulse sampling (NPS) method is adopted for model identification. Compared with the previous HC-DPD scheme, the proposed CR-HC-DPD approach greatly decreases the number of sampling points used for modeling and, in turn, reduces the computational complexity. Measurement results on a class-AB GaN PA with a 600-Hz two-tone signal demonstrated that the CR-HC-DPD scheme canceled all the harmonics for being below −60 dBc with less than 5% complexity compared with the HC-DPD scheme.

Multioctave Power Amplifier Design Using 9:1 Planar Impedance Transformer

In this letter, at the first step, design of a new broadband planar 9:1 transmission line impedance transformer is investigated and several parameters of this transformer, such as characteristic impedances of the lines, their length, and ground plane distance effects, are analyzed from a new point of view. Then, a multioctave power amplifier (PA) is implemented using the introduced transformer as input and output matching network of a power transistor. The fabricated PA achieves a power output more than 46.5 dBm with a flat gain of 10.5 ± 0.7 dB over an ultrawide frequency band from 0.5 to 3 GHz. The measured power added efficiency (PAE) is better than 50% over the whole frequency bandwidth.

The Nested-Mode Power Amplifiers for Highly Efficient Multi-Octave Applications

In this article, a novel nested-mode power amplifier (NMPA) is proposed for highly efficient multi-octave applications. By introducing a group of nested guaranteed regions (GRs) at the fundamental and harmonic frequencies as the target design space, the difficulties caused by frequency overlapping in harmonically tuned multi-octave power amplifiers (PAs) can be overcome, leading to a self-consistent theory of multi-octave PAs. Furthermore, the methodology of constructing the proposed nested GRs is demonstrated based on a simplified numerical model. According to the methodology, the desired nested GRs can be constructed by following several well-defined closed-form steps. In addition, a feasible design methodology of the NMPA is established based on a simplified deembedding technique of packaged devices. Based on the proposed theory and design method, a 1–3100-MHz NMPA is designed and measured. According to the measured results, the designed PA exhibits 57.5–73.9% drain efficiency and 39–42.6-dBm output power across the band. Moreover, the linearity and linearizability of the designed NMPA are verified using up to 20-MHz-bandwidth-modulated signals across the designed band accompanied with a digital predistortion (DPD) procedure. To the best of our knowledge, this is the state-of-the-art performance of multi-octave broadband PAs.

A 4–32 GHz SiGe Multi-Octave Power Amplifier With 20 dBm Peak Power, 18.6 dB Peak Gain and 156% Power Fractional Bandwidth

This letter presents the design and characterization results of a multi-octave power amplifier (MOPA) fabricated in a 0.13- $\mu \text{m}$ SiGe-BiCMOS technology. The single-stage power amplifier is implemented as the stack of a cascode amplifier combining broadband input matching network with resistive feedback, and a common-base amplifier with base capacitive feedback. Measurement results show that the design delivers a peak saturated output power level of 20.2 dBm, with output of 1 dB compression at 19.4 dBm. The measured 3-dB power bandwidth is from 4 to 32 GHz, covering three octaves. The corresponding power fractional bandwidth (PFBW) is 156%. The measured peak power added efficiency is 20.6%, and peak small-signal gain is 18.6 dB. The fabricated integrated circuit occupies an area of 0.71 mm2. To compare state-of-the-art MOPAs, the power amplifier figure of merit defined by the international technology roadmap for semiconductors (ITRS) is modified to include PFBW and area. To the best of authors’ knowledge, the presented design achieves the highest figure of merit among multi-octave PAs in a silicon-based integrated circuit technology reported in the literature.

A Multi-Octave Power Amplifier Based on Mixed Continuous Modes

This paper presents a multi-octave power amplifier based on mixed continuous modes. It consists of resistive-reactive series of continuous modes and a phase shift parameter. The issue of impedance duplication is solved in the case of exceeding an octave bandwidth. By introducing a phase shift parameter, the bandwidth is further expanded obviously. Then, a compact network and its design method are proposed to meet impedance requirements. For validation, a 0.5-4.0 GHz power amplifier is designed and fabricated. And the measured results show that the saturated output power is between 40.0 dBm and 42.8 dBm in target band. From 60% to 71% drain efficiency is obtained with a gain greater than 10 dB. The size of the proposed PA is greatly compact, which is only with 3.6 cm $\times6.0$ cm.

Design of Ultrawideband High-Efficiency Extended Continuous Class-F Power Amplifier

Total bandwidth of existing wireless communication technologies covers a wide frequency range of over one octave. But most existing power amplifier configurations cannot meet this requirement while at the same time maintaining a high efficiency. Therefore, a new structure that can achieve multioctave bandwidth is proposed in this paper together with the design methodology. The difficulty in realizing a bandwidth larger than one octave lies in the overlapping of fundamental and harmonic frequencies. Regarding this problem, the continuous class-F mode is extended to allow a resistive second harmonic impedance, rather than the pure reactive one. With the relaxed design requirements and overlapping design space of fundamental and second harmonic frequencies, harmonic tuning and fundamental frequency matching networks can be designed separately. More importantly, broadband matching for fundamental frequencies can be implemented simply by considering only three fundamental frequency points using the multiple frequencies matching method. To verify the validity of the proposed methodology, a multioctave power amplifier was designed, fabricated, and measured. Measured results verify a wide bandwidth of 128.5% from 0.5 to 2.3 GHz. Over this frequency range, drain efficiency was larger than 60% with output power greater than 39.2 dBm and large signal gain larger than 11.7 dB.

Design of multioctave power amplifiers based on high order resistive‐reactive series of continuous modes

AbstractIn this article, the high order resistive‐reactive series of continuous modes (H‐R‐R‐SCMs) approach is presented to design multioctave bandwidth power amplifiers (PAs). By introducing the high order resistive term, the ranges of the second harmonic impedances are expanded, which will be very effective for designing the multioctave bandwidth PAs. Based on the proposed method, a broadband high‐efficiency PA working from 0.5 to 3.1 GHz (144% relative bandwidth) is designed. According to the measured results, the PA achieves 12.0–14.3 dB power gain and 12.6–21.4 W output saturation power in the operation band. The drain efficiency varies from 56.3 to 76.6% over the whole multioctave bandwidth.

Design of Multioctave Bandwidth Power Amplifier Based on Resistive Second-Harmonic Impedance Continuous Class-F

In this letter, a generic method is presented for multioctave power amplifier (PA) based on extended version of the continuous class-F. The theory allows resistive second-harmonic impedance and sacrifices part of efficiency to get a bandwidth over one octave. A high-voltage GaN HEMT is adopted to achieve high output power and drain efficiency. Finally, a 0.2–2.5 GHz miniature multioctave PA is designed and fabricated. Experimental results show the drain efficiency of 55.5%–70.3% and the output power of 43.7–46.9 dBm across 0.2–2.5 GHz (170%). The compact size of the proposed PA can also be observed with only 2.6 cm $\times5.5$ cm, which is greatly reduced compared with other PAs with similar performances.