| | | AVX offers a series of 0402 and 0603 chip varistors, designated the AntennaGuard series, for RF antenna/RF professional amplifier protection. These devices offer ultra-low capacitance (<3pF in 0402 chips, and <3pF & <12pF in 0603 packages), as well as low insertion loss. Antenna varistors can replace output manufacturers of capacitors and provide ESD suppression in cell phones, pagers and wireless LANs. It is very common to employ some form of a FET in many types of efficient/miniature RF amplifiers. Typically, these RF transistors have nearly ideal input gate impedance and outstanding noise figures. However, FETs are very susceptible to ESD damage due to the very thin layer of SiO2 uses as the gate insulator. The ultra-thin SiO2 layer is required to improve the gain of the transistor. In other words, the upside of the performance enhancement becomes the downside of the transistors survival when subjected to an ESD event. ESD damage to the RF Field Effect Transistors (FETs) is a | | growing concern among RF designers due to the following trends: (1) RF amplifiers continue to shrink in size, and (2) FET gains figures continue to increase. Both trends relate to decreasing gate oxide thickness, which in turn, is directly proportional to increased ESD sensitivity. As miniaturization trends accelerate, the traditional methods to protect against ESD damage (i.e., PC board layout, passive industrial filters, and diode clamps) are becoming less and less effective. AVX's AntennaGuard varistor can be used to protect the FET and offer superior performance to the previously mentioned protection methods given above. The standard EIA 0603 chip size, and particularly the 0402 chip, offer designers an ESD protection solution consistent with today's downsizing trend in portable electronic products. Savings in component volume up to 86%, and PC board footprint savings up to 83% are realistic expectations. These percentages are based upon the following table and Figures 1A and 1B. | | |