Chebyshev gain functions have been widely employed for tly, matching a complex load to a resistive generator. Such transfer functions do result in optimum response when the terminations are purely resistive. However, assuming the overall transducer gain characteristic has monotone decreasing stopband behavior, the equal ripple transfer function is shown to be not optimum for a complex load. Furthermore, equalizers simpler in structure and superior in frequency response to equal ripple designs can readily be synthesized. Indeed it appears that nonoptimality will generally result whenever analytic gain-bandwidth theory is used to determine the constants of a transfer function belonging to an a priori specified class. Examples are presented for the matching of LCR and CR loads.

On optimum broad-band matching

The Internet's phenomenal growth has created the potential for a ubiquitously connected society. This potential has been slow in coming, however, in part because the majority of today's home users connect to the Internet over slow analog telephone lines. Slow modems and congestion at popular Web sites have further contributed to the "World Wide Wait". Broadband access (connections at data rates of 250 kbps or more) has long promised a solution, but until recently, technology has been unable to deliver these higher speeds at a reasonable cost. Despite this and other problems, affordable broadband access is just around the corner. What this means for users is a change that will profoundly affect Web access and the existing communication (telephone) and media (TV and radio) industries. The main drivers for narrowband's transition to broadband are new applications that will soon be available. In addition, a slew of new Internet access devices and supporting products will become available in the next few years.

http://ieeexplore.ieee.org/iel5/93/19368/00895149.pdf

Broadband networks

Broadband RF and Microwave Amplifiers provides extensive coverage of broadband radio frequency (RF) and microwave power amplifier design, including well-known historical and recent novel schematic configurations, theoretical approaches, circuit simulation results, and practical implementation strategies. The text begins by introducing two-port networks to illustrate the behavior of linear and nonlinear circuits, explaining the basic principles of power amplifier design, and discussing impedance matching and broadband power amplifier design using lumped and distributed parameters. The book then: Shows how dissipative or lossy gain-compensation-matching circuits can offer an important trade-off between power gain, reflection coefficient, and operating frequency bandwidth Describes the design of broadband RF and microwave amplifiers using real frequency techniques (RFTs), supplying numerous examples based on the MATLAB programming process Examines Class-E power amplifiers, Doherty amplifiers, low-noise amplifiers, microwave gallium arsenide field-effect transistor (GaAs FET)-distributed amplifiers, and complementary metal-oxide semiconductor (CMOS) amplifiers for ultra-wideband (UWB) applications Broadband RF and Microwave Amplifiers combines theoretical analysis with practical design to create a solid foundation for innovative ideas and circuit design techniques.

Broadband RF and Microwave Amplifiers

An inductive element of a multipole impedance transforming bandpass network of classical design such as Butterworth or Chebyshev, for example, is employed as a pick-up coil for sensing NMR signals. The network matches the high input impedance of an NMR receiver preamplifier to the low impedance of the pick-up coil. Simultaneously, and as a consequence of the impedance matching, the high preamplifier input impedance appears as a band width broadening element at the pick-up coil. By virtue of the multipole design of transformer, a bandwidth broader than the natural bandwidth of the pick-up coil is obtained and the transfer of the energy of the detected NMR signal to the preamplifier is maximized.

Low loss wide band front end for NMR receiver

http://amfone.net/Amforum/index.php?action=dlattach;topic=30492.0;attach=30926

Q-based design method for T network impedance matching

Explicit formulas for computing the optimum design parameters of the bandpass impedance-matching networks having Butterworth and Chebyshev responses of arbitrary order for a class of most practical RLC load are derived It is shown that using at most a second-order all-pass function for the equalizer back-end reflection coefficient, a bandpass impedance match is possible if and only if the series inductance of the given load does not exceed a certain critical value This is in direct contrast to the low-pass situation where we showed earlier that any given RLC load can be matched using at most the rust-order all-pass function The significance of the present results is that we reduce the design of these practical bandpass impedance-matching networks to simple arithmetic

Wai-Kai Chen

Papers

Explicit formulas for the synthesis of optimum bandpass Butterworth and Chebyshev impedance-matching networks