Design Of Channel Filters Research Articles

A Fully Integrated Multiplexer Using Unified Extracted Pole Technique

This article presents a fully integrated 12-channel multiplexer with TE011 mode channel filters enabled by the unified extracted pole technique. A novel synthesis procedure is proposed to remove the limitation (a very small coupling) in the prototype with the classical approach. In addition, this article proposes a novel approach to assign the junction susceptance by simply shifting the length of the connecting waveguide section of the dangling resonators. The design process is then extended to the singly terminated case as the channel filter design. This work also proposes a novel analytical approach to derive the initial connecting phase lengths for the manifold multiplexer design. The circuit level optimization and space-mapping procedure for deriving physical dimensions are illustrated. The multiplexer is designed and constructed using a new clamshell structure, which offers low cost, small footprint, easy fabrication, and superior thermal performance. The simulated and measured results demonstrated that the proposed theory offers an excellent solution to the high-power waveguide manifold multiplexer designs.

Synthesis of a Three-Channel Waveguide Microwave Multiplexer with a Modified Structure

The synthesis procedure of a waveguide multiplexer with a modified structure is considered. Compared with standard methods, the approach to the synthesis of this structure is based on the principle of decomposition, to simplify and accelerate the development of complicated devices. To check the performance ability of a proposed structure, the three-channel X-band waveguide multiplexer with a modified design of channel filters was synthesized. Design and experimental results are compared.

Optimal Design of Multiplier-Less Non-uniform Channel Filters with Successive Approximation of Vectors

Applications such as software-defined radio (SDR) receivers utilize channel filters to isolate the individual frequency bands of different communication standards present in a wideband input signal. Low complexity and sharp transition width are the two important design constraints of channel filters in SDR receivers. Frequency response masking (FRM) with the multiplier-less design is an effective approach for designing sharp filters with low complexity. This paper presents an optimal design for multiplier-less implementation of FRM-based non-uniform channel filters. In the proposed design, multiplier-less channel filters are realized basing upon decomposing their impulse response values in generalized bit planes. This decomposition is based on a vector successive approximation technique in which impulse responses are successively approximated using a dictionary of vectors. The resulting coefficients of channel filters belong to signed sums of powers of two form. The proposed channel filter designs are simulated using MATLAB R2017b, and the results have been compared with the existing ones in order to signify the effectiveness of the proposed design. The simulations show that the proposed channel filter design has low complexity (number of adders) and the design time is considerably low.

Manufacture oriented design of high-performance mechanical filters

With previous papers having dealt with the technology and various models of mechanical filters, the series is brought to a close with the description of the design methods. The design method is based on the Remez algorithm and allows manufacture oriented and systems oriented secondary conditions to be taken into account. The description of the fundamentals includes the determination of a converging initial circuit. As illustrated by a channel filter design, the procedure is justified and a number of suggestions are provided which guarantee satisfactory convergence even under difficult secondary conditions. It is shown that the described method avoids unwanted local minima and, therefore, theoretically provides the desired solution; it remains an open question whether another method might lead to the desired solution more quickly in special cases.

Optimum design of channel filter for digital magnetic recording

To increase recording density while maintaining satisfactory data reliability, optimum channel filters are designed by taking into account the effects of intersymbol interference and noise simultaneously. The concept of eye pattern, used in communication theory, is utilized for evaluating the effect of intersymbol interference. The eye patterns are calculated assuming linear superposition of individual reproduced pulses. Filter parameters are optimized by employing an iterative approximation method so as to maximize the signal-to-noise ratio of the worst-case data. The results show that channel equalizations are effective for an amplitude detection system but not effective for a peak detection system. The recording density limits for several recording systems are also obtained.