60GHz RFIC module
Fig. 1. Block diagram of the entire design.
With the rapid growth of wireless technologies and high-speed multimedia data communications, industry leaders worldwide are driving the technology for utilizing the 60 GHz unlicensed frequency band. Its 7 GHz absolute bandwidth allows instant massive data transmission such as uncompressed high-quality multimedia streaming, as well as sharing and backing up contents. This is the next frontier in consumer electronic connectivity in which one can replace the nest of wires in the living room with high-speed wireless technology.
The CMOS technology is being widely used in wireless communications due to its high potential for both low cost in volume production and RF / baseband co-integration. Thus, many integrated circuits are designed using the CMOS technology nowadays. However, implementation of mm-wave transceivers in CMOS technology is challenging work as the designer need to balance achieved between a good linearity and power consumption.
Antennas are a prominent component of the wireless communication system. Recent technologies for achieving 60GHz antennas can be classified into two categories. They are on-chip antennas and off-chip antennas. For the on-chip antenna, the advantages are its ease of system integration and small size. However, this approach would suffer from high substrate loss in the silicon and would result in having a poor antenna gain, typically less than 0dBi. In addition, the on-chip antenna also finds either narrow bandwidth or unstable radiation pattern. Therefore, it is not a good candidate for wideband and high speed wireless applications. Its counterpart, the off-chip antenna, is good for providing a better antenna gain with sufficient bandwidth. At millimeter wave, the antenna dimensions, particularly for the feeding structure are tiny in size that the antenna requires high-cost, high-precision fabrication process. Among many off-chip antenna designs, LTCC process is one of the commonly used technologies for 60 GHz antennas.
LTCC (Low Temperature Co-fired Ceramic) is a multilayer capable substrate technology offering excellent RF and microwave performance characteristics. Its low sintering temperature allows co-firing with highly conductive metals such as silver and gold. LTCC technology is especially beneficial for RF and high-frequency applications. In high frequency applications, LTCC technology allows direct integration of passive components such as antennas, power dividers, transmission lines, and filters. Also, the active components can be flip chip connected to the LTCC substrate. Thus, the LTCC technology has been applied to compact module implementation because of its three-dimensional (3D) integration capability, excellent metal conductivity and low-loss characteristics.
The project goal is to designed an RF transceiver at 60GHz ISM band with frequency synthesizer and control interface. Also, this transceiver will be packaged with the dual polarized antenna designed on multilayer LTCC as shown in Fig. 1.