Software & CAD

The Grid Amplifier: Enabling High Power Millimeter-wave Systems

There are a number of communications, radar and imaging applications spanning Ka-band through W-band (26 to 110 GHz) that require transmitter output powers in the range of a few watts to a few tens of watts. Vacuum-tube sources and amplifiers have long been available that can produce output power...
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An Actively-controlled Microwave Reflecting Surface with Binary-pattern Modulation

This article describes an actively-controlled reflecting surface, capable of modulating the microwave energy incident upon it. The surface is a composite structure holding an array of conventional semiconductor diodes excited with a set of pulses in a ...
For specific applications, there is a need for materials or composite structures which can reflect and/or absorb the electromagnetic (EM) energy incident upon them in a desired or controllable fashion. Such reflective EM absorbing/reflecting materials 1-3 are useful in designing smart radar cross-section (smart RCS) surfaces and radio frequency...
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An Equivalent Circuit and Modeling Method for Defected Ground Structure and Its Application to the Design of Microwave Circuits

In this article, the equivalent circuit and modeling method for a defected ground structure (DGS) is proposed, to be used in the design of a microwave circuit. Using the proposed equivalent circuit permits the optimization of the DGS circuits. Simulati...
Recently, there has been an increasing interest in studying microstrip lines with various periodic structures that prohibit wave propagation in certain frequency bands, including photonic bandgap (PBG) and DGS. 1-10 Each periodic structure has its own properties and advantages. DGS, which is realized by etching only a few areas...
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A Diode Linearizer for Microwave Power Amplifiers

The performance of communication systems, in both space and ground segments, is degraded by the nonlinearity of the power amplifiers that are operated in saturation to obtain higher efficiency. Linearizing is the technique used to improve the performance of communication systems when power amplifiers are operated in saturation. The...
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A Deterministic Method for Optimizing VSWR

By using in conjuction both frequency and time domain reflection measurements, it is possible to positively identify the specific circuit discontinuities that contribute to a given VSWR lobe. Corrective action can then be readily determined for optimum...
Improving VSWR is typically an iterative trial-and-error exercise when utilizing either frequency or time domain information. For example, while circuit modifications which decrease time domain reflectometry (TDR) "bumps" (discontinuities) are generally a good thing, decreasing a specific TDR bump does not necessarily improve VSWR within a frequency band of...
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Recent Advances in EDA Software Solutions for Improved RFIC Design Flows

Today's wireless world requires unrelenting technological innovation. From cell phones that take and send photos to homeland security, the demands on wireless designers for increasing complexity at lower prices and faster time-to-market are immense. Advances in electronic design automation (EDA) over the last decade have made possible dramatic improvements...
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