Passive Components

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Integrated voltage-controlled capacitors, usually known as varactors, are used in many electronic integrated devices for RF applications. 1 In particular, voltage-controlled oscillators (VCO) 2,3 and tuneable filters 4 are the two main applications. For good performance of integrated devices that have a varactor as a component, it is very...

In many applications, such as balanced power amplifiers, mixers and antenna systems, power dividers/combiners are required. Power dividers using quarter-wave lines become prohibitively large at the lower frequencies and result in MMIC chips of larger size and higher cost. The lumped-element approach, which uses lumped inductors and capacitors, is...

In the telecoms and other RF component markets, today's climate means that there can no longer be a trade-off between cost and performance - the designer needs to achieve both. Temex has recognized this fact and addressed it through the evolution of two new generations of materials on which...

One of the greatest challenges in characterizing new coaxial interfaces is to determine an accurate test configuration. When precision airlines are not available it is very difficult to obtain a true measurement of the device under test. It becomes necessary to design and implement calibration standards to eliminate the...

Precise device characterization is the starting point of any good circuit design. This task can be particularly challenging when the device is a high power transistor having low input and output impedances. For devices working only under pulse conditions, specific test benches exist 1 but are rather complicated and...

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...

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...

In today's competitive marketplace the characterization of RF semiconductor devices for modeling, design, applications and process improvement must be faster, more efficient, and more repeatable and accurate as companies strive to improve their product performance, design productivity and time to market. However, help is on hand with the Wavevue...

A new product line of ultra linear bandpass filters has been introduced that utilize patent pending cross coupling to reduce time delay and phase distortion up to 90 percent. The filters typically utilize a 12-section filter with two inductive and two capacitive non-adjacent couplings to equalize and flatten the...

On December 13, 2002, we sent a questionnaire to 75 companies that provide products and services in this field, with a response deadline of January 11th. We used e-mail rather than the USPS so that we would have feedback that all the questionnaires were received. On January 3, 2003,...