| Autor: |
Stephan Marksteiner, Ngoc-Hoa Huynh, Robert Aigner, Martin Handtmann |
| Rok vydání: |
2005 |
| Předmět: |
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| Zdroj: |
IEEE MTT-S International Microwave Symposium Digest, 2005.. |
| Popis: |
Bulk acoustic wave (BAW) and FBAR technologies offer key advantages for transmit filters which are used between the power amplifier and antenna in cell phone applications. The classical challenge for Tx filters in duplexers is to achieve low insertion loss, high return loss, high Rx - Tx isolation and good wideband performance at the same time. The trade-offs between those parameters can be modeled in a straightforward approach as will be briefly described. The main section of this paper discusses 2nd order effects which become relevant at high power levels. The energy loss in each individual BAW resonator generates a shift and spread of resonance frequencies in the filter elements by self-heating effects. These effects can cause unexpected performance issues and may even lead to thermal instability. A concept for modeling of self-heating effects is presented in detail. The role of self-heating with regard to power-handling capability of a filter will be pointed out. As a consequence of extreme energy density at high power levels a certain degree of non-linear effects can be observed in BAW/FBAR filters. The origin of these effects will be discussed as well as a modeling strategy. This is in particular important for emerging W-CDMA applications of BAW and FBAR filters. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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