Many ready-to-run GNSS modules are built with an on-board TCXO encapsulated under a metal lid. For reasons beyond the scope of this article (related to the spread-spectrum characteristics of CDMA and FDMA), the metal lid neither reduces electromagnetic interference nor increases sensitivity of GNSS receivers. Indeed, if the design doesn’t comply with the characteristics of the TCXO, the metal lid can in fact have an adverse effect on system performance. Ultra-small 1.6mm x 2.0mm TCXO packages are readily available and frequently used to address space constraints and complexity in PCB layouts, significantly increasing system cost while neither improving performance nor providing a versatile solution for different application environments. Read More
