A 2.4 GHz CMOS class-F power amplifier with reconfigurable load-impedance matching

© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.A novel reconfigurable CMOS class-F power amplifier (PA) at 2.4 GHz is proposed in this paper. It is able to match the output load variations mainly due to the effect of hand and head on a mobile phone. The effect of load variation on power-added efficiency (PAE), output power, and distortion is compensated by reconfiguring the output network using an impedance tuner. The tuner controls the output matching at fundamental frequency without affecting the class-F harmonic tuning up to 3rd harmonic. To the best of our knowledge, this is the first design of a CMOS class-F PA addressed to compensate the effect of load variation. Measurement results for 50 ohm load impedance show a maximum PAE of 26% and maximum output power of 19.2 dBm. The measured total harmonic distortion is 4.9%. Measurement results for load values other than 50 ohm show that PAE increases from 6.5% (not-tuned PA) up to 19.9% (tuned PA) with the same output power (19.2 dBm). Tuning also reduces the adjacent-channel leakage ratio by 5 dB and the spectral regrowth of a Wi-Fi signal at the PA output. The size of the fabricated chip is 1.6 mm × 1.6 mm.Peer ReviewedPostprint (author's final draft

A very low distortion high efficiency class-F power amplifier at 900 MHz.

This paper presents a novel class - F power amplifier for mobile applications in which with a proper harmonic tuning structure the need f or an extra fil tering section is eliminated . A class - F power a mplifier employing a GaN HEMT device has been designed, fabricated and measured at 900 MHz . The fabricated circuit achieves a n excel lent harmonic - suppression level and the t otal h armonic distortion is around 1.2% . It overcomes the narrow band performance of class - F power amplifier s, giving more than 70% efficiency over a 100 MHz bandwidth . Experimental results show that the amplifier is able to deliver 38.5 dBm output power while achieving the state - of - the - art PAE of 8 0.5 % with a peak drain eff iciency of 8 4 % , and a power gain of 13.6 dB for an input power of 25 dBm . A good agreement between measurement and simulation results is observed for the proposed structure.Peer ReviewedPostprint (published version

Generalized transverse resonance analysis of planar discontinuities considering the edge effect

Mode-matching related techniques such as the Generalized Transverse Resonance Method (GTR) suffer from the relative convergence phenomenon. To reduce its influence, we present a technique consisting of the application of basis functions incorporating the singular behavior of fields at edges and an optimal modal ratio. We present the results obtained analyzing a uniform finline and a short-circuited finline which demonstrate the minimization of the relative convergence phenomenon, allowing a fast and accurate analysis on a low-cost personal computer.Peer Reviewe

An assessment of different relay network topologies to improve Earth-Mars communications

The future of deep space communications encompasses a challenging situation where the current facilities used to communicate with different spacecraft may become saturated as a result of an increasing number of missions and their complexity. From this forecast, the present study intends to provide a solution to saturation problems through strategically-located upgradable relays for Earth-Mars communications. The foremost goal of this paper is to quantitatively uncover the potential enhancements coming from relay placement in strategic orbits between Earth and Mars. Herein, two relay configurations –a.k.a. network topologies– are analyzed: the Lagrange-relays network topology and a circular, homogeneously-distributed satellite constellation, acknowledged here as pearl constellation. The first uses the Earth-Sun system Lagrange points L3, L4 and L5 as potential locations for the relays, whilst the second defines an optimized orbit between Earth and Mars with 3 or 4 relay satellites. To aid in the analysis, the authors developed an open-sourced piece of software that obtains the link availability as well as the data rate at which two nodes may communicate, taking as a reference the Deep Space Network for Earth, and the Mars Reconnaissance Orbiter for Mars. For complex topologies with more than two communicating nodes, the software outputs the end-to-end bit rate and optimal communication route at each time step. Moreover, this product is extensible to analyze and optimize any network topology and could be adapted to be used for contact management and mission planning in the future. The results show that the network-topology proposals are an advantageous option to significantly increase the link availability of Earth-Mars communications. Nevertheless, the Direct-To-Earth link always outperforms the multi-hop path due to the limited telecommunication system’s capabilities of both the spacecraft and the relays. As a result of this, the study includes an analysis on the requirements of the relay’s design in order to make the constellation a beneficial and comparable alternative to the DTE link. This way, the proposed network topologies become a suitable option whom to share with the DSN communications workload, providing enhanced bit rates and data volumes as well as higher availability of the communication.Peer ReviewedPostprint (published version

High efficiency reconfigurable class-F power amplifier at 2.4 GHz in CMOS-MEMS technology

A novel reconfigurable CMOS class-F power amplifier is proposed in this paper which can adapt to load variations resulted from the hand effect on a mobile phone. Reconfigurability is achieved by using MEMS switches that are integrated monolithically in the CMOS technology along the rest of the circuit, reducing the cost and size. This structure integrates MEMS varactor inside CMOS technology that are built through a mask-less post-processing technique. Designed for 2.4GHz, for a load impedance of 50O, simulations results show that the power amplifier achieves a power added efficiency of 32.8% and a power gain of 12.9 dB, while delivering peak output power of 18.2 dBm. Simulation results for different load variations have been performed showing a great improvement in efficiency and output power by using the proposed structure. The total size of the fabricated chip is 1.6 mm x 1.6 mm.Peer ReviewedPostprint (published version

Lens based switched beam antenna for a 5G smart repeater

A 16 switched beam lens based antenna with a coverage area of ±30° in the horizontal plane and from 0 to -20° in the vertical plane has been built and tested. The intended use of the antenna is as part of a smart repeater servicing the coverage area of a 5G wireless communication system operating in the n258 band of the 5G Frequency Range 2, from 24.25 to 27.5 GHz. The antenna has been built using state-of-the-art materials and components in order to assess the performance of this antenna concept. The overall antenna losses including the feeding network are of the order of 8 dB and the realized gain in the 80% of the coverage area is above 11 dB.This work was funded in part by AEI: PID2019-107885GB-C31/AEI/10.13039/501100011033 and HUAWEI TECHNOLOGIES Italia S.r.lPeer ReviewedPostprint (author's final draft

Anàlisi, simulació i optimització d'una transició línia coaxial - guia coplanar amb el programari CST Microwave Studio

En aquest document presentem un resum de les tasques realitzades per tal de modelar, simular i optimitzar la transició entre una línia coaxial de secció quadrada i una guia coplanar sobre un substrat de silici a la banda de 43 GHz a 60 GHz. L'eina de simulació utilitzada és el programa "CST Microwave Studio v. 5.0".Preprin

Anàlisi de discontinuïtats finline

En esta tesis se han desarrollado los siguientes métodos numéricos para el análisis de estructuras planares, especialmente finline, en la banda de microondas y ondas milimétricas: -el método de las líneas con discretizacion uniforme y no uniforme. -el método de los elementos finitos aplicado al análisis de guías homogéneas e inhomogeneas. -el método de la matriz de lineas de transmisión tridimensional. -el método de la matriz se generalizada para el análisis de estructuras uniformes y discontinuidades planares. -el método del dominio espectral para el análisis de estructuras planares uniformes. -el método del circuito planar con corrección de la dispersión. Se ha elegido el método de la resonancia transversal generalizado como el mas idóneo para el análisis preciso y rápido de discontinuidades finline con un mínimo de recursos informáticos. Se ha desarrollado incluyendo el carácter singular de los campos en las aristas de la estructura, consiguiéndose minimizar el fenómeno de la convergencia relativa y obteniéndose resultados precisos con expansiones reducidas de las funciones modales que representan los campos, validándose los resultados obtenidos al analizar diversas estructuras con medidas experimentales.Postprint (published version

Notes sobre el programari "Micro-Stripes" v.6.1. de la casa "Flomerics"

Report de recerca internPreprin

Procés de disseny i simulació amb "ADS Momentum" d'una bifurcació en "Y" a 45º de guies coplanars amb interruptors MEMS

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