Sistema de medidas de PIM en componentes pasivos
Tutor / director / evaluatorCollado Gómez, Juan Carlos
Document typeBachelor thesis
Rights accessRestricted access - author's decision
One of the greatest problems of telecommunications services is the high occupancy of the radio spectrum with high power signals outside the band of interest of a particular communications system. These out of band signals can generate interference in the own system, reducing its performance, especially reducing the dynamic range of the receivers, which ends out limiting the length of the possible link. If out of band signals can be and are filtered in the early stages of the receiver, sharing the antenna with the transmitter that works with high power signals can generate intermodulation products that can be in the reception band of our system if the antenna itself or the early stages of filtering are not completely linear, although they are passive components. On the other hand, high spectrum occupancy and the amount of services that must coexist forces to set tight restrictions on the transmission of out of band signals in a specific service. These out of band transmissions, may be due to different factors such as: a poor filtering of the modulated signal, or the creation of harmonic and intermodulation products from active and passive components in the transmission chain. The generated components by the active components of the transmitter can be filtered, but not the ones generated by the filters themselves or the antenna itself. Therefore the study of passive intermodulation (PIM) is becoming more important and the linearity requirements of passive components are becoming stronger. This final degree thesis proposes the creation of a measures system of PIM in passive RF components based on the cancellation of the high power signals that affect the device to be measured before they are measured by the spectrum analyzer. This system is complex and allows various configurations so it has also been designed an emulator in order to try different measurement system settings, to obtain the optimum configuration, and implement it without engaging the integrity of the different elements of the system. Specifically we will take special care of the power amplifiers and the spectrum analyzer, because a misuse of the system could result in burning these elements by an uncontrolled high power input.