advertisment Advertisement
This ad will close in  seconds. Skip now
advertisment Advertisement
advertisment Advertisement
advertisment Advertisement
advertisment Advertisement

Subsystems and Systems

Development of an Advanced Airborne Precipitation Radar

January 1, 2003
Radar has been used for observation of weather since the 1940s. 1 Advances in weather radar include the incorporation of Doppler capability, which allows measurement of wind velocity, and the use of multiple polarizations, which enhance rainfall estimation and provide the ability to discriminate between types of hydrometeors, such...
Read More

An RF Module Design for a Multi-mode Handset

This article describes a novel design of an RF module for a multi-mode handset and presents an example of an RF module for a W-CDMA/GSM/DCS tri-band and dual-mode handset. The entire module, including a direct modulation transmitter and a superheterody...
January 1, 2003
The number of mobile users is predicted to reach 1.7 billion by the year 2010. More than 45 percent of them will use high data speed services. W-CDMA, proposed by IMT2000, has become the most practical and important system for the development of new wireless communications. Nevertheless, second generation...
Read More

A Minimalist Approach to Feedforward Multi-carrier Linear Power Amplifiers

A feedforward multi-carrier linear power amplifier with 60 W maximum average output is featured
December 1, 2002
Atmospheric propagation attenuation is known to be higher in the 2.1 GHz band than in the cellular band. Thus, to overcome this performance disadvantage and to maximize cell coverage and capacity, Unity Wireless System's first feedforward multi-carrier linear power amplifier (MCLPA) product has been designed with a high 60...
Read More

Understanding W-CDMA Modulation Quality Measurements

December 1, 2002
There are many ways of characterizing W-CDMA transmitter performance. However, the Third Generation Partnership Project (3GPP) specifications require two measurements to verify the in-channel modulation quality of W-CDMA transmitters - error vector magnitude (EVM) and peak code domain power (peak CDE). This article explores the purpose behind these key...
Read More

A Handheld Spectrum Analyzer Offering High Performance from a Small Footprint

November 1, 2002
The prime requirements of a handheld spectrum analyzer are for it to be lightweight, compact, but with as large a display as possible, and exhibit low power consumption - all within a sturdy housing. These criteria are not easy to fulfill in themselves, so it is an even greater...
Read More

Precision E<sub>b</sub>/N<sub>o</sub> Generators for BER Testing to 44 GHz

November 1, 2002
With the continually increasing complexity of digital modulation techniques employed in wireless and satellite communications systems, instruments that accurately generate and maintain a set level of bit energy-to-noise density ratio (E b /N o ) have become valued tools in optimizing bit-error rate (BER) performance. These instruments have been...
Read More

Effects of AM/AM and AM/PM Distortion on Spectral Regrowth in 3GPP W-CDMA BS Power Amplification

The effects of amplitude and phase nonlinearities in a power amplifier, which lead to spectral regrowth, are examined in the context of a 3GPP W-CDMA forward link (base station) environment. Behavioral modeling and simulation techniques are applied fir...
November 1, 2002
The transmitter unit, contained in base stations for third generation cellular systems, requires a linear power amplifier to preserve signal integrity when amplifying composite signals associated with multiple channels. While the power amplifier must meet a number of requirements to be system level compliant, the design process generally emphasizes...
Read More

A Broadband Hybrid Solid-state and TWT Amplifier

Development of a broadband microwave amplifier for testing in the 800 MHz to 18 GHz frequency range
September 1, 2002
Test applications that require microwave power from 1 to 18 GHz are usually addressed by two amplifiers, a solid-state unit to cover the low frequency range and a traveling-wave tube amplifier (TWTA) for the higher range. The input signal must be switched between the two amplifiers and, if there...
Read More

The Receiver Noise Equation: A Method for System Level Design of an RF Receiver

Introduction to a new equation used to simplify the system level design of an RF receiver
August 1, 2002
Noise is a limiting factor for sensitive reception. In recent communication receivers, noise, along with many external factors, including intermodulation, reciprocal mixing and spurious response, may disturb the sensitive reception of the desired signal. Thus, much consideration for the noise and other factors that disturb the signal reception and...
Read More

Internally Terminated 12-throw Electromechanical Switches for Matrix Applications

Presentation of a single-pole 12-throw internally terminated electromechanical switch that forms the basis for a line of N x 12 switch matrix assemblies
July 1, 2002
Electromechanical distribution systems (switch matrices) are used in both commercial applications and military systems. Computer control of these switch matrices facilitates their use in automated testing and in those systems requiring remote control of switching functions. The newest product in Dow-Key's line of electromechanical switches is a single-pole 12-throw...
Read More

Sign-In

Forgot your password?

No Account? Sign Up!

Get access to premium content and e-newsletters by registering on the web site.  You can also subscribe to Microwave Journal magazine.

Sign-Up

advertisment Advertisement