Industry News

RSS

Technical Note Design and Prototyping of a Transimpedance Front-end Amplifier for Dense Wavelength Division Multiplexing Circuits As part of the development of an optical power monitor for use in dense wavelength division multiplexing (DWDM) circuits, the effectiveness of a logarithmic operational amplifier transimpedance front-end amplifier was investigated, and the...

Application Note Fast Design of Cross-coupled Filter Substructures Cross-coupled narrow bandpass filters with asymmetric transmission zeros can be realized in cascaded tri-section topology.1,2,3 Each tri-section creates a single transmission zero below or above the passband. The realization of resonator tri-sections is relatively difficult due to the interaction between the...

PRODUCT FEATURE  Integrating System and Circuit Simulation Capabilities Applied Wave Research Inc. (AWR) El Segundo, CA Version 5.0 of Microwave Office Design Suite will begin shipping in the fourth quarter of this year. The new release, called Microwave Office 2002, includes integrated system simulation capabilities that close the gap...

COVER FEATURE Exploring a Three-dimensional Universe CST of America Inc. Wellesley, MA Engineers are branching out. Gone are the days when 3D electromagnetic fields belonged to the specialized domain of antenna and cavity filter designers. Today's higher frequencies and the compact nature of designs are forcing engineers to take...

PRODUCT FEATURE A 17 to 27 GHz GaAs MMIC Gain Block Amplifier from Multiple Sources Mimix Broadband Webster, TX A GaAs MMIC three-stage gain block amplifier covering the 17 to 27 GHz frequency range has been developed that features the option of individually biasing the three stages or biasing...

TECHNICAL FEATURE Finite Element Determination of the Intrinsic Small-signal Equivalent Circuit of MESFETs The finite element time domain method is used to determine the intrinsic elements of a broadband, small-signal equivalent circuit (SSEC) of FETs. The values of the different elements are calculated from the Y parameters of the...

A New Spread-spectrum Measurement Method for Satellite Transponder In-orbit Testing This article introduces a new measurement method for beginning-of-life and in-service testing of satellite transponders that utilizes spread-spectrum signals. The basics of this new method, which permit measurement of amplitude and group delay of a transponder channel, are presented....

TECHNICAL FEATURE A High Efficiency Bow-tie Antenna for Impulse Propagation An investigation into the problems associated with using modified dipole antennas to propagate temporally short electrical impulses is described. Experimental data is presented which shows that the time domain characteristics of the bow-tie antenna can be improved by reactively...

TECHNICAL FEATURE A Method of Measuring Large-signal S-parameters of High Power Transistors A measurement method for scattering parameters (S-parameters) of high power transistors is presented. The proposed method directly determines the S-parameters of high power transistors by measuring overall gain, phase and S-parameters of input and output matching network...

TECHNICAL FEATURE Improved Gain for a Dynamic Envelope Tracking Amplifier in Cellular Radio Handsets An envelope tracking (ET) amplifier with variable bias voltage is a potentially more efficient power amplifier technique for third generation cellular phones. However, the input and output impedances of the transistors vary with the bias...