dBm Saturated Power Research Articles

A 28 GHz transformer-based Doherty power amplifier for FR2 5G applications in 40 nm CMOS

ABSTRACT In this paper, a 28 GHz transformer-based Doherty power amplifier (DPA) is designed in Huali Microelectronics (HLMC) 40 nm CMOS process. The impedance inverter is converted into transformer form to calculate and design the power combiner based on the transformer voltage combination. A switchable cap array is added to the auxiliary output to increase the robustness of the active load modulation. The DPA achieves 17.1 dBm saturated power with 33.67% peak power added efficiency ( PA E max ) and 19.93% PA E PBO 6 dB at 6 dB power back-off.

Ultrafast MUTC photodiodes over 200 GHz with high saturation power.

Novel back-illuminated modified uni-traveling-carrier photodiodes (MUTC-PDs) with wide bandwidth and high saturation power are demonstrated. The effect of cliff layer doping on the electric field distribution is investigated to achieve fast carrier transport. MUTC-PDs with miniaturized device diameter and low contact resistance are fabricated to improve the RC-limited bandwidth. Meanwhile, inductive peaking is implemented to further extend the bandwidth. PDs with 3-µm and 3.6-µm-diameter exhibit a ultrawide bandwidth of 230 GHz and 200 GHz, together with -4.94 dBm and -2.14 dBm saturation power at 220 GHz and 200 GHz, respectively.

Quantum-noise-limited microwave amplification using a graphene Josephson junction.

Josephson junctions (JJs) and their tunable properties, including their nonlinearities, play an important role in superconducting qubits and amplifiers. JJs together with the circuit quantum electrodynamics architecture form many key components of quantum information processing1. In quantum circuits, low-noise amplification of feeble microwave signals is essential, and Josephson parametric amplifiers (JPAs)2 are the widely used devices. The existing JPAs are based on Al-AlOx-Al tunnel junctions realized in a superconducting quantum interference device geometry, where magnetic flux is the knob for tuning the frequency. Recent experimental realizations of two-dimensional (2D) van der Waals JJs3-5 provide an opportunity to implement various circuit quantum electrodynamics devices6-8 with the added advantage of tuning the junction properties and the operating point using a gate potential. While other components of a possible 2D van der Waals circuit quantum electrodynamics architecture have been demonstrated, a quantum-noise-limited amplifier, an essential component, has not been realized, to the best of our knowledge. Here we implement a quantum-noise-limited JPA using a graphene JJ, that has a linear resonance gate tunability of 3.5 GHz. We report 24 dB amplification with 10 MHz bandwidth and -130 dBm saturation power, a performance on par with the best single-junction JPAs2,9. Importantly, our gate-tunable JPA works in the quantum-limited noise regime, which makes it an attractive option for highly sensitive signal processing. Our work has implications for novel bolometers; the low heat capacity of graphene together with JJ nonlinearity can result in an extremely sensitive microwave bolometer embedded inside a quantum-noise-limited amplifier. In general, this work will open up the exploration of scalable device architectures of 2D van der Waals materials by integrating a sensor with the quantum amplifier.

Erbium-Doped Lithium Niobate Thin Film Waveguide Amplifier With 16 dB Internal Net Gain

Erbium-doped lithium niobate on insulator (Er:LNOI) has attracted enormous interest as it provides gain and enables integrated amplifiers and lasers on the lithium niobate on insulator (LNOI) platform. We demonstrate a highly efficient waveguide amplifier on Er:LNOI. The 2.58-cm long amplifier can achieve 27.94 dB signal enhancement, 16.0 dB internal net gain (6.20 dB/cm), −8.84 dBm saturation power, 4.59 dB/mW power conversion efficiency, and 4.49 dB noise figure at 1531.6 nm. Besides, thorough investigation on the pumping wavelength, pumping scheme, output power and noise figure have been performed to provide a comprehensive understanding on this novel waveguide amplifier. This work will benefit the development of a powerful gain platform and can pave the way for a fully integrated photonic system on LNOI platform.

A Dual-Band and Dual-State Doherty Power Amplifier Using Metal-Integrated and Substrate-Integrated Suspended Line Technology

In this article, a novel design method of dual-band and dual-state (DBDS) Doherty power amplifier (DPA) is proposed. Considering the actual parasitic parameters, the DPA can be designed by using the impedance transformation of saturation and back-off points at dual frequency bands of DBDS as well as second harmonic matching. The DBDS DPA for dual-band (DB) 5G application, i.e., 3.4 and 4.9 GHz band are designed and implemented, for the first time, by using metal-integrated and substrate-integrated suspended line (MI-SISL) technology, which has advantages of high performance and self-packaging. The fabricated DBDS DPA achieves the measured 44 and 43.2 dBm saturated power at 3.4 and 4.9 GHz bands, respectively. For the 3.4 and 4.9 GHz bands, the measured drain efficiency (DE) is 70.7% and 70.4% at peak power levels and 38% and 42% at a 6-dB output back-off, respectively. When driven by a 20- and 100-MHz modulated signal with 6-dB peak-to-average power ratio (PAPR), the adjacent channel leakage ratio is better than −27 dBc at operating frequencies. The average output power of 38 and 37 dBm with an average efficiency of 37.9% and 40.9% is achieved at 3.4 and 4.9 GHz, respectively.

Bandwidth Enhancement of Doherty Power Amplifier Using Modified Load Modulation Network

A novel Doherty power amplifier (DPA) architecture with extended bandwidth is presented in this paper. A modified load modulation network is introduced to provide impedance condition required by the Doherty operation in a wide frequency range. Analytical parameter solutions of the proposed load modulation network and the related load modulation process are presented. A DPA with 2.80-3.55 GHz bandwidth utilizing commercial GaN transistors is implemented. The fabricated DPA attains a measured 9.3-11.1 gain and 43.0-45.0 dBm saturated power. 50.0-60.6% and 66-78% drain efficiency is obtained at 6 dB output power back-off and saturation throughout the designed band, respectively. Moreover, the back-off drain efficiencies are higher than 55% within 700 MHz bandwidth. When driven by a 6-carrier 120 MHz OFDM signal with 7.0 dB peak to average power ratio, the proposed DPA achieves adjacent channel leakage ratio of better than −50 dBc after digital pre-distortion (DPD) at 3.20 GHz with average efficiency of 53.3%.

A 28 GHz Single-Input Linear Chireix (SILC) Power Amplifier in 130 nm SiGe Technology

This article presents an integrated high-efficiency 28 GHz power amplifier (PA) employing a combination of Chireix outphasing and Doherty architectures in order to simultaneously achieve power back-off efficiency and linearity with a single RF input signal and no predistortion. The amplifier consists of a dual-input high-efficiency outphasing PA and a simple input network which serves as a power splitter and feeds the same signal to the inputs of the main and auxiliary PA cells that are biased in class-AB and class-C regions, respectively, similar to the Doherty architecture. The operation of the PA cells together with the Chireix combiner result in back-off efficiency enhancement plus systematic AM-AM and AM-PM variations which are used to correct the distortions caused by transistors, resulting in a linear response. The implemented PA demonstrates 19 dBm saturation power (Psat) with 34.4% peak power-added efficiency (PAE) and 6 dB back-off PAE of >23% at 27.5 GHz. The modulated signal performance using a 100 MHz 64QAM OFDM signal shows an average output power of 11.9 dBm with PAE >20%, EVM < 5%, and ACLR < −33 dBc without using predistortion.

An $X$ -Band 29.6-dBm CMOS Power Amplifier Using Folded Radial Splitter and Binary Combiner Network

An ${{X}}$ -band fully integrated power amplifier (PA) has been designed and fabricated on CMOS technology. Utilizing a transformer-based folded radial power splitter and binary power combiner network, the CMOS PA delivers 29.6 dBm saturation power ( ${{P}}_{\mathbf {sat}}$ ) at 11 GHz. The measured gain is 11.2 dB, the output of 1-dB compression point ( ${{OP}}_{\mathbf {1\,dB}}$ ) is 28.2 dBm, and the peak power-added efficiency (PAE) is 15.5% at 11 GHz. To our knowledge, the PA achieves the highest ${{P}}_{\mathbf {sat}}$ and the highest ${{OP}}_{\mathbf {1\,dB}}$ among other reported CMOS PAs around ${{X}}$ -band to date.

A Compact +10/+5 dBm 800/2600 MHz LTE Driver Amplifier With Ground-Bounce Reduction

A reconfigurable, compact, dual-band radio frequency driver amplifier (DA) is presented. The proposed DA operates in the 800 and 2600 MHz LTE bands using a single inductor for both bands. The single-ended DA demonstrates a ground bounce reduction technique using a series- LC resonant network at the source of the amplifying device, which also improves overall gain. It is fabricated on a TSMC 65-nm CMOS process and measurement results show that it is capable of delivering up to 16.5/14.5 dBm saturated power at a drain efficiency of 35.7%/32.2%. When driven with a 10 MHz 16-QAM LTE signal, it delivers a modulated power of +10/+5 dBm at a drain efficiency of 14.5%/7.5%, and exhibits an ACPR of −40 dBc. The DA consumes a power of 69/42.2 mW from a 2.5-V supply, and occupies an overall area of 0.48 $\text {mm}^{{2}}$ .

Hybrid Analog/Digital Continuous Class B/J Mode for Broadband Doherty Power Amplifiers

In this paper, a new digitally driven two input continuous mode Doherty power amplifier (DPA) architecture is proposed along with an analytical-based generic output combiner network design methodology. The load combiner provides the designer a choice to meet the optimum performance for any arbitrary back-off as well as for saturation. The PA’s performance is further optimized with digital input splitting. To verify the proposed theory, a 20-W symmetrical continuous mode DPA is designed using 10-W GaN HEMTs. The proposed amplifier shows a drain efficiency between 56.0% and 75.4% at 41.4–44.6 dBm saturation power and between 45% and 56.5% at 35.7–38.5 dBm output power corresponding to 6-dB back-off. This performance is achieved over the band from 1.25 to 2.3 GHz that corresponds to 59.15% fractional bandwidth. The proposed hybrid analog/digital continuous mode DPA prototype is implemented using field-programmable gate array (FPGA)/DSP platform and qualifies the spectral mask when excited by a modulated long term evolution signal along with digital predistortion.

A 183 GHz Desensitized Unbalanced Cascode Amplifier With 9.5-dB Power Gain and 10-GHz Band Width and −2 dBm Saturation Power

A novel approach to design a mm-wave high power gain cascode amplifier is proposed. The gain is enhanced by adjusting the size of the cascode transistor together with a desensitized inductive impedance at its base. The impedance at this node has a critical role in determining both gain and stability. The employed desensitization technique decreases the effect of process variations and modeling errors on this impedance which results in a reliable design. Providing enough degrees of freedom, this method results in a conjugate matched input and output impedances. Therefore, two or more of this stage can be simply cascaded to get higher gain with no need for an interstage matching network and hence no additional loss and gain degradation. Based on this approach, a single stage amplifier at 183 GHz is implemented in a 130 nm SiGe process which has a measured power gain of 9.5 dB, 3 dB bandwidth of 8.5 GHz and saturation power of −2.8 dBm.

A 5.8 GHz class-AB power amplifier with 25.4 dBm saturation power and 29.7% PAE

In this paper, an effective and succinct radio-frequency (RF) grounding technique for class-AB power amplifier (PA) is presented. The proposed technique employs a grounding path, resonant with a capacitor in series at the center of the fundamental and second-order harmonic frequencies, between the critical ground nodes, to ensure a low impedance path. The power loss due to imperfect grounding is then reduced by 2 dB, and the saturated output power and power added efficiency (PAE) are therefore significantly improved. A fully integrated 5.8-GHz PA with the proposed technique is designed and implemented in a 65-nm CMOS process. Measured result shows a saturated output power of 25.4 dBm and a peak PAE of 29.7%, while with only 2.5 V of supply voltage.

Wideband millimetre‐wave CMOS power amplifier using transistor‐based inductive source degeneration and specially shielded transformer

This study presents integration of transistor based inductive source degeneration and specially shielded transformer into a millimetre-wave power amplifier (mm-wave PA) operating at wideband. A new configuration of high Q distributed inductor is devised and embedded in CMOS transistor source to enhance stability, maximum stable gain and bandwidth of mm-wave CMOS PAs. The source inductance selection is conveniently investigated by the proposed admittance matrix condensation. In power splitting and combining part, a novel X-shape pattern-ground shielding is inserted in high turn ratio transformer to ameliorate wideband matching. Based on these techniques, a fully differential mm-wave PA was implemented in 65 nm low-power CMOS with 0.25 mm2 core area. The measurement results show that its differential drive gain and common mode rejection ratio are above 10 and 26 dB, respectively, in a wide frequency range of 41 to 61 GHz, while the power added efficiency (PAE) is still above 10.8% at 46–62 GHz. This CMOS PA also achieves 11.9 dBm output referred 1-dB compression point (P 1 dB) and 15.2 dBm saturated power (P sat) with 12.4% peak PAE.

A 60-GHz Dual-Mode Distributed Active Transformer Power Amplifier in 65-nm CMOS

This paper presents a 60-GHz power amplifier (PA) fabricated in a 65-nm CMOS technology. The proposed PA utilizes a dual-mode amplification circuit topology to achieve a high level of output power and efficiency in a small die area. High-output power is achieved by combining class AB cascode stage with a conventional class A common source (CS) stage in a compact four-way differential distributed active transformer to increase the amplifier’s power density. Driver stages consist of an enhanced cascode stage followed by a CS stage to achieve a high power (HP) gain. Fabricated in a 65-nm CMOS process, the maximum measured gain of the 60-GHz PA is 22 dB within a wide 3-dB bandwidth of 14 GHz. A maximum saturated output power of 19.7 dBm is measured in HP mode while consuming 430 mW over a 1.2 V core supply. In low-power (LP) mode of operation, the power gain of 20 dB and 19.7 dBm saturated power is measured at 60 GHz. The proposed dual-mode topology achieves an HP added efficiency of 25% and 19% in HP and LP modes, respectively.

New Advances on Heterogeneous Integration of III–V on Silicon

Recent advances on hybrid III–V/Si lasers and semiconductor optical amplifiers using wafer bonding are reported. Hybrid optical amplifiers exhibit 28 dB internal gain, 9 dBm saturation power in the output silicon waveguide, and 10–11 dB of internal noise factor. Moreover, using optical amplifiers as optical gates, we demonstrate a successful switching operation of optical packet/burst without penalties compared to classical optical amplifiers. The hybrid silicon lasers allow single mode operation and wavelength tunability over 30 nm by exploiting silicon ring resonators thermo-optical effect. Moreover transmission over 60 km single-mode fiber at 10 Gb/s from a directly modulated III–V on Silicon hybrid laser is also demonstrated. Finally, we achieved 21.4 Gb/s modulation over 12 wavelengths using a high-speed directly modulated silicon hybrid laser with improved E/O bandwidth.

Clamping Op-Amp를 이용한 광대역 로그 비디오 증폭기의 선형성 개선에 관한 연구

본 논문은 0.5~2.0 GHz에서 -70~0 dBm의 동적 범위를 갖는 로그 비디오 증폭기(Successive Detecting Log Video Amplifier, 이하 SDLVA)를 설계 및 제작하였다. 제작된 SDLVA는 5단의 증폭기를 이용한 고주파 출력부, 2단의 로그검파기 그리고 선형성 개선을 위하여 클램핑 연산증폭기를 이용한 가산 회로로 구현하였다. 제작된 SDLVA의 측정 결과는 73 dB 이상의 소신호 이득과 10.1~12.2 dBm의 고주파 포화 출력 특성을 갖는다. 그리고 -70~0 dBm 입력 시 25 mV/ dB<TEX>${\pm}$</TEX>1.0 mV의 기울기를 갖고 <TEX>${\pm}$</TEX>1.5 dB 이하의 선형 특성을 갖는 비디오 신호를 출력한다. This paper describes a design and fabrication of SDLVA. The SDLVA operates 0.5~2.0 GHz with -70~0 dBm dynamic range. The SDLVA is consisted of 5-stage RF block, 2-stage detector block and summation circuit using clamping op-amp to improve video linearity. The result of measure, SDLVA of RF path has over 73 dB small-signal gain and 10.1~12.2 dBm saturation power. The video path has 25 mV/ dB<TEX>${\pm}$</TEX>1.0 mV and under <TEX>${\pm}$</TEX>1.5 dB video linearity.

A 4 W K-band GaAs MMIC power amplifier with 22 dB gain

A 4 W K-band AlGaAs/InGaAs/GaAs pseudomorphic high electron mobility transistor (PHEMT) monolithic microwave integrated circuit (MMIC) high power amplifier (PA) is reported. This amplifier is designed to fully match for a 50 Ω input and output impedance based on the 0.15 μm power PHEMT process. Under the condition of 5.6 V and 2.6 A DC bias, the amplifier has achieved a 22 dB small-signal gain, better than a 13 dB input return loss, and 36 dBm saturation power with 25% PAE from 19 to 22 GHz.

Gain properties and optical-feedback suppression of asymmetrical curved active waveguides

Elaborately-designed asymmetrical curved active waveguides are introduced to improve the gain properties of semiconductor optical amplifiers (SOAs) by internal distributed optical-feedback suppression. An analytical model of the double-energy-level system is utilized in the simulation and designed by the finite difference time domain (FDTD) method. Under a 280 mA driving current, the optimized curved SOA with the simple device structure without isolators performs a more than 18 dB fiber-to-fiber gain, 980 μW spontaneous emission power, and 13 dBm saturation power.

A Ku band four-stage PHEMT 1W MMIC power amplifier

A successful development of a very high performance and reliable power PHEMT MMIC technology is reported. In this paper, a Ku-Band 1W AlGaAs/InGaAs/GaAs PHEMT MMIC power amplifier for VSAT ODU application is demonstrated. This four-stage amplifier is designed to fully match for a 50Ω input and output impedance. With 7V and 700mA DC bias condition, the amplifier has achieved 30dB small-signal gain, 30.8dBm 1-dB gain compression power with 24.5% power-added efficiency (PAE) and 31.3dBm saturation power with 27.5% PAE from 14 to 17GHz.

Second Window Optical Amplifiers: Comparison of Different Pumping Wavelengths and Fibers

Praseodymium-doped fluoride fiber amplifiers at 1300 nm with different configurations and pumping sources have been developed. Performances obtained with various pumping wavelengths and active fibers are compared. The best results obtained with pumping at 1047 nm are 32.4 dB internal gain and 13.4 dBm saturation power.