Publicação
Smart analog passive circuits using ferroelectric materials for software defined radio systems
| Resumo: | The designs of radio systems are advancing toward fully digital transceivers, which implies that the input signal should pass through an analog to digital converter. This thesis investigates the evolution of smart analog circuits, including input filters and phase shifters, that may be implemented in tunable radio frequency chains for more efficient spectrum use. The limitation of possible jammers are examined utilizing the inovative feautures of these devices and somehow allow all signals within the dynamic range of the converter in a software-defined radio approach. The unique features of this work are focused on the development of input analog radio frequency front-ends that are adaptable in frequency and power, which may vary according to the bias voltage and input power. This research relied on ferroelectric based devices that have predicted variable capacitance and nonlinear behavior at microwave frequencies for wireless and satellite communications. Using the peroviskite of Barium Strontium Titanate, the properties of ferroelectric thick and thin films are intensively explored. BST films provide numerous desirable features for high frequency applications, including field-dependent permittivity and a high breakdown field. The ratios of Barium and Strontium that enable operation at room temperature in the paraelectric phase are examined. Different device topologies for implementing BST capacitors for low voltage applications have been researched throughout several implementations. Among the challenging solutions, there are presented tunable RF devices and three-functional-dimension analog radio frequency front-ends that can adjust its three functional dimensions (frequency, output power, and bias voltage) and limit the dynamic range by employing ferroelectric thick and thin films. |
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| Autores principais: | Bouça, Patricia Alexandra Pereira |
| Assunto: | Tunable microwave filters Dual-band bandpass filter Ferroelectric devices Barium strontium titanate Power limiters Frequency selectivity Electrophoretic deposition Sol-gel Intermodulation distortion Nonlinear measurements |
| Ano: | 2022 |
| País: | Portugal |
| Tipo de documento: | tese de doutoramento |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade de Aveiro |
| Idioma: | inglês |
| Origem: | RIA - Repositório Institucional da Universidade de Aveiro |
| Resumo: | The designs of radio systems are advancing toward fully digital transceivers, which implies that the input signal should pass through an analog to digital converter. This thesis investigates the evolution of smart analog circuits, including input filters and phase shifters, that may be implemented in tunable radio frequency chains for more efficient spectrum use. The limitation of possible jammers are examined utilizing the inovative feautures of these devices and somehow allow all signals within the dynamic range of the converter in a software-defined radio approach. The unique features of this work are focused on the development of input analog radio frequency front-ends that are adaptable in frequency and power, which may vary according to the bias voltage and input power. This research relied on ferroelectric based devices that have predicted variable capacitance and nonlinear behavior at microwave frequencies for wireless and satellite communications. Using the peroviskite of Barium Strontium Titanate, the properties of ferroelectric thick and thin films are intensively explored. BST films provide numerous desirable features for high frequency applications, including field-dependent permittivity and a high breakdown field. The ratios of Barium and Strontium that enable operation at room temperature in the paraelectric phase are examined. Different device topologies for implementing BST capacitors for low voltage applications have been researched throughout several implementations. Among the challenging solutions, there are presented tunable RF devices and three-functional-dimension analog radio frequency front-ends that can adjust its three functional dimensions (frequency, output power, and bias voltage) and limit the dynamic range by employing ferroelectric thick and thin films. |
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