RF & Microwave Industry News

Design of a Feedback Predistortion Linear Power Amplifier

A new feedback predistortion linearizing method is proposed and analyzed. This method extracts the third-order intermodulation distortion (IMD) signal from the main power amplifier (PA) output signal and the original input signal and uses it as the pre...
Mobile communication systems currently use multi-carrier/multi-channel schemes for effective use of the frequency spectrum resources. The intermodulation has a serious impact on these communication systems in terms of adjacent channel interference, resulting in an increase of bit error rates. As the power amplifier operates close to the saturation region...
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Techniques for the Integration of High-Q Millimeter-wave Filters in Multi-function MMIC Modules

There has been a widespread trend toward higher levels of integration in microwave and millimeter-wave system design, motivated by a desire to reduce cost, size and complexity, particularly as many old applications are being re-invented in array architectures. The most commonly used format for achieving high levels of integration...
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An Archery-target Antenna

The "archery-target" antenna presented in this article is a directional antenna evolved from the short-backfire antenna (SBFA). The new antenna has an additional annular reflector and a much-increased large reflector when compared to the SBFA. The arch...
Parabolic-reflector antennas are widely used as microwave directional antennas. Unfortunately, the illumination of a parabolic mirror becomes rather inefficient when the dimensions of the mirror are not large enough compared to the wavelength. On the other hand, the directional gain of microwave cavity antennas1 is rather small, since it...
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A Novel Frequency Doubler Using a Feedforward Structure and DGS Microstrip for Fundamental and High Order Components Suppression

A novel design of a frequency doubler, using a feedforward technique and a defected ground structure (DGS), is described. In the proposed frequency doubler, the feedforward loop suppresses the fundamental component (fo), and the DGS attenuates the high...
The demand for a signal source with high stability and low phase noise increases in microwaves, millimeter-wave communications and radar systems. High frequency signal sources can easily be obtained by multiplying low frequency signals that have relatively high stability and low phase noise. In general, however, frequency multipliers include...
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A Quasi-balanced Frequency Doubler Using Alternate Power Dividing and Combining Techniques

The design and analysis of a novel balanced-like high conversion gain frequency doubler is presented, employing alternate power dividing and combining techniques. In this design approach, all positive and negative cycles of the sinusoidal source signal...
Due to the inherent upper limit in operating frequency of active devices in local oscillators, a frequency multiplier, in conjunction with a low frequency local oscillator, has often been used as a signal source, providing better overall phase-noise performance and low cost realization. 1 A balanced configuration has been...
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GaAs-, InP- and GaN HEMT-based Microwave Control Devices: What is Best and Why

The properties of a single-pole, single-throw (SPST) switch using various technologies (InP-, GaAs- and GaN-based HEMTs) are reviewed and discussed in the context of their suitability for microwave and RF control applications. Insertion loss, isolation...
Solid-state switches based on high electron mobility transistors (HEMT) can be fabricated with a variety of different semiconductor technologies, usually selected on the basis of performance requirements. Such solid-state switches have been used successfully as control devices for transmitter and receiver switching functions in various digital communications systems. In...
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Characteristic Analysis of a Low Profile Post-type Monopole Antenna with Dual Plate

A low profile monopole antenna with dual plates (a shorted, inverted L-shaped planar plate and a gap planar plate) has been studied experimentally to obtain a large bandwidth and an enhanced radiation pattern. In this proposed antenna, the shorted plan...
A monopole antenna is a very simple and efficient radiating element.1 However, this antenna suffers from a limited bandwidth and distorted radiation characteristics. In the coming generation of mobile communications, multimedia services will be provided by a mobile handset, which must therefore be equipped with a broadband antenna. It...
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Design Curves for Estimating the Resonant Frequency and Q-factor for Rectangular Dielectric Resonator Antennas

Analysis and design curves for rectangular dielectric resonator antennas (DRA) are presented. The curves, based on the dielectric waveguide model, allow a designer to quickly predict the resonant frequency and Q-factor of a rectangular DRA without the ...
Dielectric resonator antennas (DRA) are a relatively recent addition to antenna technology and have been the focus of increasing research activity over the last two decades. A DRA is a resonant antenna fabricated from low loss microwave dielectric material whose resonant frequency is predominantly a function of size, shape...
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Around the Circuit

Industry News Spectrum Control Inc. , a designer and manufacturer of electronic control products and systems, announced that Spectrum Microwave Inc., its wholly-owned subsidiary, has acquired substantially all of the assets and assumed certain liabilities of Amplifonix Inc . Amplifonix, Philadelphia, PA, is a designer and manufacturer of RF...
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