Design and Synthesis of Parallel-Connected Dielectric Filter Using Chain-Function Polynomial

Design and synthesis of parallel connected die-lectric filters using chained function polynomials are pre-sented in this paper. This filter will offer reduced sensitivity to fabrication tolerance while preserving its return loss response within the desired bandwidth in comparison to traditional Chebyshev filters. A novel transfer function FN according to chained is derived for fourth and sixth-order filters and the synthesis technique is presented. To demon-strate the feasibility of this approach, the circuit simulation based on parallel connected topology is carried out in ADS while the design and simulation of the fourth-order filter in dielectric technology in HFSS. Considerable sensitivity analysis is conducted to prove a better fabrication toler-ance of the filter. In terms of implementation, this design technique will serve as a very useful mathematical tool for any filter design engineer

Design and Synthesis of Parallel-Connected Dielectric Filter Using Chain-Function Polynomial

Design and synthesis of parallel connected die-lectric filters using chained function polynomials are pre-sented in this paper. This filter will offer reduced sensitivity to fabrication tolerance while preserving its return loss response within the desired bandwidth in comparison to traditional Chebyshev filters. A novel transfer function FN according to chained is derived for fourth and sixth-order filters and the synthesis technique is presented. To demon-strate the feasibility of this approach, the circuit simulation based on parallel connected topology is carried out in ADS while the design and simulation of the fourth-order filter in dielectric technology in HFSS. Considerable sensitivity analysis is conducted to prove a better fabrication toler-ance of the filter. In terms of implementation, this design technique will serve as a very useful mathematical tool for any filter design engineer

Design of Compact Parallel-Connected Chained Function Filters

The design of compact parallel-connected chained function filters is presented in this paper. The proposed filters will offer reduced sensitivity to manufacturing tolerance within the specified bandwidth in comparison to conventional Chebyshev filters for C-band applications. A new filtering function according to a chained configuration is derived for fourth-order filters, and the synthesis procedures are presented. To demonstrate the feasibility of this approach, the circuit simulation based on parallel-connected topology is performed in an advanced design system, while the design and simulation of a fourth-order filter in dielectric technology are carried out in high-frequency simulation software. The prototype of fourth-order microstrip topology is fabricated using open-loop resonators. The overall circuit size of the filter is 2.5 cm × 4 cm. The achieved simulation and measured insertion/return loss are 0.409 dB/20 dB and 2.674 dB/18.074 dB, respectively. Extensive sensitivity analysis is conducted to prove the fabrication tolerance of the filter. The reduced sensitivity of the proposed filter to manufacturing tolerance is fully demonstrated using an open-loop microstrip technology, and its reliability is proven by theoretical analysis. The prototype results in this research are validated and agree with the theoretical results. In terms of implementation, this design technique will be a very useful mathematical tool for any filter design engineer

3-D printing quantization predistortion applied to sub-THz chained-function filters

This paper investigates physical dimension limits associated with the low-cost, polymer-based masked stereolithography apparatus (MSLA) 3-D printer, with 50 μm pixels defining the minimum print feature size. Based on the discretization properties of our MSLA 3-D printer, multi-step quantization predistortion is introduced to correct for registration errors between the CAD drawing and slicing software. This methodology is applied to G-band 5th order metal-pipe rectangular waveguide filters, where the pixel pitch has an equivalent electrical length of 8.5° at center frequency. When compared to the reference Chebyshev filter, our chained-function filter exhibits superior S-parameter measurements, with a low insertion loss of only 0.6 dB at its center frequency of 182 GHz, having a 0.9% frequency shift, and an acceptable worst-case passband return loss of 13 dB. Moreover, with measured dimensions after the 3-D printed parts have been commercially electroplated with a 50 μm thick layer of copper, the re-simulations are in good agreement with the S-parameter measurements. For the first time, systematic (quantization) errors associated with a pixel-based 3-D printer have been characterized and our robust predistortion methodology has been successfully demonstrated with an upper-millimeter-wave circuit. Indeed, we report the first polymer-based 3-D printed filters that operate above W-band. As pixel sizes continue to shrink, more resilient (sub-)THz filters with ever-higher frequencies of operation and more demanding specifications can be 3-D printed. Moreover, our work opens-up new opportunities for any pixel-based technology, which exhibits registration errors, with its application critically dependent on its minimum feature size