Microstrip diplexer design based on two square open loop bandpass filters for RFID applications

In this work, a simple and efficient approach to design a microstrip diplexer is proposed. It is based on the combination of two compact Square Open Loop Resonator band pass filters. These filters are designed for Radio Frequency Identification application at 2.45 GHz frequency. Using the Chebychev approximation, the two filters and diplexer are designed, simulated, fabricated, and measured. The results show that the diplexer presents a high selectivity, a good insertion loss and high isolation (>40 dB) with the compact size. The diplexer also shows a good performance when associated with the patch antenna operating at 2.45 GHz.

Effective Bounds on Strong Unicity in L1-Approximation

<p>In this paper we present another case study in the general project of Proof Mining which means the logical analysis of prima facie non-effective proofs with the aim of extracting new computationally relevant data. We use techniques based on monotone functional interpretation (developed in [17]) to analyze Cheney's simplification [6] of Jackson's original proof [9] from 1921 of the uniqueness of the best L1-approximation of continuous functions f in C[0, 1] by polynomials p in Pn of degree <= n. Cheney's proof is non-effective in the sense that it is based on classical logic and on the non-computational principle WKL (binary K¨onig lemma). The result of our analysis provides the first effective (in all parameters f, n and epsilon) uniform modulus of uniqueness (a concept which<br />generalizes `strong uniqueness' studied extensively in approximation theory). Moreover, the extracted modulus has the optimal epsilon-dependence as follows from Kroo [20]. The paper also describes how the uniform modulus of uniqueness can be used to compute the best L1-approximations of a fixed f in C[0, 1] with arbitrary precision, and includes some remarks on the case of best Chebychev approximation.</p>

Optimal Design of the Geometric Parameters of a Disk Cam Translating Follower Mechanism Using Chebychev Approximation

A method for the structural design of a cam-translating roller follower mechanism with the minimum volume and least maximum pressure angle is presented. The design is formulated as a two-objective optimization problem subject to multiple constraints. The hierarchical approach for handling multi-objective optimization and application of the Chebychev approximation scheme for solving the nested maximization-minimization problem are discussed. The method presents a forthright approach to the complex optimal structural design of a cam-follower mechanism, and significantly improves present cam-follower mechanism design and optimization methods. A design example is used to illustrate the approach.