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Ultra-precision Service This company’s Web site offers a complete ultra-precision service for grinding, lapping, polishing, diamond sawing, laser machining and sizing a wide variety of metals (ferrous and non-ferrous). The company also offers carbide, ceramic, sapphire and other materials for industrial and scientific applications in the telecommunications, semiconductor, communications,...
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The Design of a Dual Polarized Vivaldi Array

In this article, the design of a dual polarized Vivaldi antenna array is described. The Vivaldi elements are fed by broadband microstrip-to-slotline baluns. A 2:1 bandwidth (3.4 to 7 GHz) was achieved for VSWR, gain and cross-polarization isolation. Th...
The design for the Vivaldi antenna is motivated by the need for a broadband measurement antenna for an antenna test range (ATR). The ATR is capable of a dual axis rotation to create 3-D plots and to calculate the total radiated power (TRP). 1 The TRP calculation involves the...
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Potential Applications of PBG Engineered Structures in Microwave Engineering: Part II

The second part of this article reviews the potential applications of electromagnetic bandgap (EBG) structures in enhancing the performance of waveguides and antennas. A conductor-backed coplanar waveguide (CB-CPW) free of spurious transmission and a t...
In the new millennium, the explosion of info-communication technologies has brought many new broadband design challenges. To meet these challenges, designers are required to fulfill more functionality per unit volume. In the first part of this article, the basic PBG configurations and application of PBG structures in enhancing the...
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Automating and Optimizing High Performance LTCC Design

Low temperature co-fired ceramic (LTCC) is an increasingly popular technology that has the potential for increased reliability, improved electrical performance, size reduction and reduced cost. The LTCC process allows passive components such as resistors, inductors and capacitors to be embedded in a multilayer, integrated module with high density and...
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The Analysis and Design of a User Equipment Grade, All Digital Gain Control, Direct Conversion Radio Receiver

The analysis and design of a state-of-the-art, user equipment grade, all digital gain control, direct conversion radio receiver is presented. The receiver employs a logarithmic amplifier in the analog baseband to compress the signal dynamic range befor...
The direct conversion, all digital gain control (DC-ADGC) radio receiver employs logarithmic amplifiers in the analog baseband to compress the signal dynamic range before the analog-to-digital converter. An antilog function may then be used in the digital baseband to decompress the signal. Two implementations of the DC-ADGC receiver are...
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Volterra Series Analysis of a Laser Diode Predistorter for Mobile Communication Systems

Linearization of multiple quantum well (MQW) lasers by predistortion requires optimization of the predistorter to match the laser characteristics. A Volterra series model of a predistorter is investigated over a frequency range appropriate to the secon...
The direct transponding of RF signals onto optical fiber is an important element in the implementation of efficient radio-over-fiber systems. MQW lasers exhibit transfer functions from RF to light, which generally offer good linearity, but adequate dynamic range for applications in cellular and cordless systems requires further improvement in...
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