Advanced design, technology & manufacturing for high volume and low cost production

Abstract

Over the last years, the Low Temperature Co-fired Ceramic (LTCC) technology has proven its extreme efficiency for compact and reliable radio-frequency (RF) modules for wireless communication. LTCC technology is widely present in switches, power amplifiers and Bluetooth modules for handsets. No doubt that this technology will also be adopted for the WLAN (wireless local area network) modules in a very short term. However LTCC solutions often suffers from the reputation to be difficult to design, few flexible and expensive specially versus the very well known solutions based on printed circuit boards (PCB). DT Microcircuits and Thales Microelectronics launched together an important study to simplify the design and reduce the cost of WLAN modules based on LTCC technology. This paper summarizes this 12 months study. RF designers studied the different architectures and integration levels applied to WLAN modules. Fundamental elementary blocks, like baluns, filters, power amplifiers (PA) and switches were identified and described as a function of possible architectures, specifications and pre-selected technologies. They were implemented in LTCC substrates individually and all together. Several more or less complex LTCC modules were designed, simulated, manufactured and tested. The study proved the ability to efficiently implement the different components of a WLAN front-end module (FEM) in LTCC, whatever the chosen technologies and architectures: embedded LTCC components (filters, switches), surface acoustic waves (SAW) filters, PIN diodes or GaAs switches and PA. It allows customers to save an important time in the design of their WLAN LTCC modules.