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Software Radio, A Modern Approach to Radio Engineering Jeffrey H. Reed Prentice Hall PTR 565 pages; $92 ISBN: 0-13-081158-0 Software radios represent a major change in the design approach for radios in which a large portion of the functionality is implemented through programmable signal processing devices, giving the radio...

Upcoming generations of cellular radio systems such as GSM EDGE or UMTS require increasing power levels to meet linearity requirements of transmitted signals. To reduce overall costs, equipment manufacturers aim at reducing the number of transistors in their RF power amplifiers. The consequence is a constant demand for bigger...

The CMC-SOIC8 ceramic SOIC8 surface-mount package is ideal for packaging RF/microwave MMIC and discrete devices for applications from DC to 18 GHz. This new addition to CMC's standard product line is fabricated using aluminum nitride (AlN), a ceramic material with thermal conductivity of 180 W/m-K, about 10 times higher...

A comb generator is a device with outputs that are multiple harmonics of an input signal. The output spectral tone lines are uniformly spaced at integer multiples of the input reference. A spectrum analyzer display of the output looks much like the teeth of a comb, which is how...

Used for remote sensing in various applications and environments, microwave and millimeter-wave radiometers (RM) require frequent calibration. Microwave radiometers measure noise temperature using a suitable antenna which is designed to match a scene of interest, as shown in Figure 1 . In a technical sense, if the antenna's main...

Wireless communications handsets are increasing in functionality through the addition of features such as GPS, color displays and PDA functions. At the same time the handset is maintaining a roughly constant price and size target. Because of this trend, handset manufacturers are requiring higher levels of integration from component...

As wireless systems evolve from second- to third- or fourth-generation, the linearity, efficiency and bandwidth requirements for power amplifiers become more stringent. Many techniques, including feedforward, envelope feedback and manifold types of predistorters, have been employed to effectively satisfy these performance requirements and to reduce the production costs for...

In multi-carrier power amplifiers, a feedforward technique is generally adopted due to its extremely linear and broadband characteristics. 1 However, the feedforward technique requires large circuits and is expensive because of its complexity. It uses two cancellation paths, and delay lines are inserted in each path to adjust the...

For the third-generation (3G) mobile radio standards, a very high linearity transmitter that can support high crest factor signals is necessary. High linearity and high efficiency are critical issues in amplifier design. In fact, as the power amplifier operates close to the saturation region where both high efficiency and...

Cellular base station receivers work in the presence of high level blockers/interferers while being required to sense weak signals of interest at the antenna. The interferers are usually rejected by filters but only at an intermediate frequency (IF) after the first down conversion. The LNA and mixer preceding the...