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TECHNICAL FEATURE Limitations in Feed-forward Linearization: Part II This article analyzes the effects of main path amplifier distortion characteristics on feed-forward systems. Part 1 ( Microwave Journal , August 2000) described the basic operation of a feed-forward amplifier system and the impact of nonideal effects on the ability of...

TECHNICAL FEATURE Effects of RF-circuit Nonlinear Distortion on Digitally Modulated Signals in Wireless Communications Computer simulation and measurement of the error vector magnitude (EVM) and adjacent-channel power ratio (ACPR) of a 2.4 GHz MMIC power amplifier (PA) and a 2.4 GHz transceiver RF front end for digital wireless communications...

TECHNICAL FEATURE Applying Switched Gain Stage Concepts to Improve Efficiency and Linearity for Mobile CDMA Power Amplification Efficiency and linearity of the power amplifier contained in second-generation (2G) CDMA cellular mobile radios are critical parameters. Further system application of power control where the mobile unit transmits output power levels...

TECHNICAL FEATURE Liquid Sensing at Radio Frequencies Combining RF measurements of complex impedance and a database of measurements can produce a sensing system to detect, identify and quantify changes to liquids and other materials in near real time. Thomas J. Warnagiris Southwest Research Institute San Antonio, TX C omplex...

TECHNICAL FEATURE Stabilization of RF Parameters of Injection-locked Pulsed IMPATT Oscillators The methods for RF parameter stabilization of injection-locked pulsed impact avalanche and transit time (IMPATT) oscillators during a pulse width over the locking band in a wide range of ambient temperatures are described. A combination of current compensation...

EUROPEAN SUPPLEMENT The International Broadband Wireless Jigsaw From ramp-up to near-3G services to developing broadband wireless for fixed network access, this year has seen major moves in the deployment of wireless services and technology introductions. In this special supplement, Microwave Journal surveys the impending international changes and developments in...

TECHNICAL FEATURE High Performance Wideband MMIC Low Noise Amplifiers This article presents two fabricated 0.25 µm first-pass pHEMT wideband MMIC low noise amplifiers (LNA) covering 1 to 8 GHz and 5 to 20 GHz, respectively. Wideband MMIC LNAs are usually designed with the emphasis on noise figure, which sacrifices...

TUTORIAL The Basics of Print Reciprocal Dividers/Combiners Leo G. Maloratsky Rockwell Collins, Air Transport Systems Melbourne, FL A reciprocal divider can provide an equal or unequal power split between two or more channels. Because of their reciprocity, these networks may also be employed to combine the power of a...

TECHNICAL NOTE Intermodulation Product Second-order Interferers in Dual-band Systems Werner Wild Spinner Company München, Germany T he problem caused by the generation of intermodulation products within modern mobile communication systems where nonlinearities are present is already well known and discussed. A variety of attempts to reduce or eliminate intermodulation...

APPLICATION NOTE Analysis of Photonic Bandgap Surfaces Using Ansoft HFSS Richard Remski Ansoft Corp. Grand Prairie, Tx T he microwave industry recently found-new uses for concepts familiar to solid-state designers in the form of photonic band gap (PBG) constructions. PBG constructions offer the ability to produce substrates, ground planes...