Application Notes

The main problem when designing PCBs using any I2C device is that data and clock are always being transmitted and fed to the transceivers. This can lead to problems with radiation unless suitable precautions are taken. Coupling from the SCL and SDA lines can often occur where these lines are long tracks leading to the synthesiser. The SCL and SDA lines pose particular problems as clock and Fig.3 Layout and decoupling of synthesiser supply pins DRIVE VEE RF RF

GaAs FET devices are typically used in low-noise amplifiers in the microwave frequency region where silicon transistors can’t provide the required gain and noise performance. There are, however, many applications in the frequency range below 2 GHz where the low noise figures and high gain of GaAs FETs can improve receiver sensitivity. Typical applications include low noise amplifiers (LNAs) in the 800 to 900 MHz frequency range for use in cellular telephone and pager applications and spread spectrum transceiver

This application note describes a method of designing oscillators using small signal s parameters. The background theory is first developed to produce the design equations. These equations are then applied to develop three different oscillators: a 4 GHz bipolar lumped resonator oscillator, a 4 GHz bipolar dielectric resonator oscillator, and a 12 GHz GaAs FET dielectric resonator oscillator. Theory Microwave transistors can be used for both amplifier and oscillator applications. From the small signal s parameters of the transistor,

This application bulletin describes the use of the ATF-36077 in a 5.7 GHz application. The ATF-36077 amplifier uses microstripline matching circuitry to obtain a low noise stable amplifier with good input and output return loss. Design The input microstripline network matches the ATF-36077 for low noise and reasonable input return loss. The output microstripline network provides a conjugate impedance match for maximum associated gain. Some resistive loading is used to improve stability. Quarterwave bias decoupling lines with low frequency