Design and Evaluation of an L-Band Current-Mode Class-D Power Amplifier Integrated Circuit

Power amplifiers (PAs) convert energy from DC to high frequencies in all radio and microwave transmitter systems be they wireless base stations, handsets, radars, heaters, and so on. PAs are the dominant consumers of energy in these systems and, therefore, the dominant sources of system cost and inefficiency. Research has focused on efficient solid-state PA circuit topologies and their optimization since the 1960s. The 2000s saw the current-mode class-D (CMCD) topology, potentially suitable for today\u27s wireless communications systems, show promise in the UHF frequency band. This thesis describes the design and testing of a high-efficiency CMCD amplifier with an integrated driver stage. In addition, analysis of a merged PA-mixer circuit based on the CMCD is provided

Passive and active components development for broadband applications

Recently, GaN HEMTs have been proven to have numerous physical properties, resulting in transistors with greatly increased power densities when compared to the other well-established FET technologies. This advancement spurred research and product development towards power-band applications that require both high power and high efficiency over the wide band. Even though the use of multiple narrow band PAs covering the whole band has invariably led to better performance in terms of efficiency and noise, there is an associated increase in cost and in the insertion loss of the switches used to toggle between the different operating bands. The goal, now, of the new technology is to replace the multiple narrow band PAs with one broadband PA that has a comparable efficiency performance. In our study here, we have investigated a variety of wide band power amplifiers, including class AB PAs and their implementation in distributed and feedback PAs.Additionally, our investigation has included switching-mode PAs as they are well-known for achieving a relatively high efficiency. Besides having a higher efficiency, they are also less susceptible to parameter variations and could impose a lower thermal stress on the transistors than the conventional-mode PAs. With GaN HEMTs, we have demonstrated: a higher than 37 dBm output power and a more than 30% drain efficiency over 0.02 to 3 GHz for the distributed power amplifier; a higher than 30 dBm output power with more than a 22% drain efficiency over 0.1 to 5 GHz for the feedback amplifier; and at least a 43 dBm output power with a higher than 63% drain efficiency over 0.05 to 0.55 GHz for the class D PA. In many communication applications, however, achieving both high efficiency and linearity in the PA design is required. Therefore, in our research, we have evaluated several linearization and efficiency enhancement techniques.We selected the LInear amplification with Nonlinear Components (LINC) approach. Highly efficient combiner and novel efficiency enhancement techniques like the power recycling combiner and adaptive bias LINC schemes have been successfully developed and verified to achieve a combined high efficiency with a relatively high linearity

Direct integration of push-pull amplifier and aperture coupled antenna

The work described in this thesis concerns the integration of push-pull class B amplifier and antenna modules. Push-pull class B is well-known with its fruitful advantages of using differential feeding technique, resulting in low distortion, reasonably high efficiency and high output power. Meanwhile, the antenna module in this work is adapted from the aperture-coupled antenna structure due to its degree of freedom to control the variables which provide the best possible topology that could be realised in system on chip or system in package. More generally, the variables allow good coverage of the Smith Chart so that a wide range of odd-mode matching requirements could be met, for different devices and bias condition of a given transistor. The approach also offers additional filtering up to 3rd harmonic in that it comprises identical harmonic traps on both sides of the aperture using resonant stubs to form bandstop filters, which reduce the ripples at the output waveforms, giving them a significant advantage of neat and tight integration of a push-pull transmitting amplifier

Modelagem de transformadores em circuitos integrados utilizando tecnologia CMOS na faixa de 1 a 10 GHz

Orientador: Prof. Dr. Bernardo LeiteTese (doutorado) - Universidade Federal do Paraná, Setor de Tecnologia, Programa de Pós-Graduação em Engenharia Elétrica. Defesa : Curitiba, 15/05/2023Inclui referênciasResumo: Este trabalho define um modelo elétrico, com parâmetros concentrados, equivalente a transformadores coplanares em circuitos integrados na tecnologia CMOS com plano de blindagem, para a faixa de 1 a 10 GHz. Este modelo é obtido a partir de otimização e a partir das características físicas deste transformador. O modelo elétrico equivalente é comparado com o transformador simulado com o método de elementos finitos (FEM) considerando as suas indutâncias, resistências e o acoplamento entre enrolamentos. O resultado de associação série somativa e subtrativa, além de seu comportamento em um oscilador controlado por tensão também são comparados com o transformador simulado. Adicionalmente um método para o cálculo do acoplamento magnético, baseado em áreas equivalentes é proposto. O erro máximo (dos parâmetros S) entre o modelo elétrico equivalente e o transformador simulado ficaram menores que 6 % para os circuitos otimizados e 8 % para os circuitos calculados, tornando seu uso possível em projeto de circuitos de radiofrequência nesta faixa de frequência e para esta tecnologia.Abstract: The main goal of this work is to define an electrical model, with lumped parameters, equivalent to coplanar transformers to be used in CMOS integrated circuits, to operate between 1 GHz and 10 GHz, using a shield plane. This model is obtained from optimization and from the physical characteristics of this transformer. The equivalent electrical model is compared with the transformer simulated using the finite element considering its inductances, resistances and coupling between windings. The result of summative and subtractive series association, in addition to its behavior in a voltage-controlled oscillator are also compared with the simulated transformer. Additionally, a method for calculating the magnetic coupling based on equivalent areas is proposed. The maximum error (S parameters) between the equivalent electrical model and the simulated transformer was less than 6% for the optimized circuits and 8% for the calculated circuits, making its use possible in the design of radiofrequency circuits in this frequency range and for this technology