Subsystems and Systems
Description of a CMOS-based front-end downconverter used to downconvert incoming satellite signals from 1.575 GHz to an intermediate frequency of 1.023 MHz
January 1, 2002
Product Feature A CMOS-based Front-end Downconverter for GPS Applications Valence Semiconductor Irvine, CA The industry is striving for single-chip Global Positioning System (GPS) designs given the limited real estate available within cell phones, personal digital assistants (PDA) and other consumer electronic devices. Since GPS designs are typically comprised of...
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Use of antenna optimization to ensure antenna pointing requirements are kept to a minimum
January 1, 2002
Technical Feature Antenna Selection to Minimize Pointing Requirements Traditionally, when designing a satellite communications system, an allowance is made in the link budget for pointing loss. The earth station's antenna size is then selected to achieve the desired gain margin. In this article, a different approach called antenna optimization...
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Introduction to a new power amplifier developed to reduce amplified noise and intermodulation distortion signals using a feedforward technique
January 1, 2002
Technical Feature A Feedforward Power Amplifier with Loops to Reduce RX Band Noise and Intermodulation Distortion This article proposes a new power amplifier approach for the reduction of amplified noise signals in the receiver (RX) band as well as intermodulation distortion signals in the transmitter (TX) band using a...
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Analysis of carrier triple beats that create third-order intermodulation interference when two or more carriers are present in one channel
January 1, 2002
Technical Feature Topics in Communication System Design: Carrier Triple Beats Howard Hausman Miteq Inc. Hauppauge, NY Intermodulation interference is typically calculated based on two signals present in the RF or IF bandwidth. When the bandwidth is less than an octave, even-order intermodulation products, such as second- and fourth-order intermodulation...
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Introduction to a wideband multichannel simulator with eight fading channels, 70 MHz RF bandwidth and spatial channel modeling
December 1, 2001
Product Feature A Hardware Multichannel Simulator for Wideband Wireless Systems Elektrobit Kauniainen, Finland Hardware-based multipath fading simulators have traditionally been used to generate up to two simultaneous fading channels. Mobile network testing and future wireless applications like geolocation, smart antennas and multiple input multiple output (MIMO) systems, however, require...
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A new suite of high performance vector network analyzers is featured
October 1, 2001
Cover Feature Vector Network Analyzers For Measurements to 50 GHz Agilent Technologies Inc. Santa Rosa, CA The HP 8510 vector network analyzer introduced by Hewlett-Packard in 1985 revolutionized microwave measurements by combining advanced techniques for characterizing components with the computational power afforded by the microprocessor. For the first time,...
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Development of an ultra-linear power amplifier that operates from 2110 to 2170 MHz and delivers 15 W of output power with 45 dB of gain
October 1, 2001
Product Feature An Ultra-linear 3G Power Amplifier Unity Wireless Systems Corp. Burnaby, B.C., Canada Fig. 1 The amplifier's typical intermodulation performance. Third Generation (3G) wireless is the next phase in wireless communications, defined by the migration to packet-switched networks at high speed data rates. 3G capability will be a...
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Explanation of the improvement gained by applying space diversity techniques to the orthogonal frequency division multiplex system in a multipath fading environment
October 1, 2001
Technical Feature Orthogonal Frequency Division Multiplex Overview Ali Zamanian Fluor Corp. Wireless broadband, also called wireless cable, was developed to provide local access to small business and residential users for the delivery of high quality digital data, video and voice services. Orthogonal frequency division multiplex (OFDM) is a modulation...
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Framework for analyzing and predicting the power spectral sidelobe regrowth from soft saturating amplification of data signals having small percentage carrier ripple
October 1, 2001
Technical Feature Regrowth of Data Spectral Sidelobes from AM/PM Effects and Hard Limiting Frank Amoroso Santa Ana, CA A previous article 1 set forth a framework for analyzing and predicting the power spectral sidelobe regrowth from soft saturating amplification of data signals having small percentage carrier ripple. The results...
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Introduction to the regulatory and operational issues which influence linearity requirements and frequency planning aspects of high frequency microwave radios used for point-to-point or point-to-multipoint systems
October 1, 2001
Special Report Linearity Requirements for MMICs for 16 Through 128 QAM ETSI Compliant Radios Jim Harvey Mimix Broadband Webster, TX This article highlights some of the regulatory and operational issues that influence linearity requirements and frequency planning aspects of high frequency microwave radios used for point-to-point or point-to-multipoint systems....
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