Substrate Loss Effects Research Articles

Design and Modeling of a Compact Partially Transmissible Resistor-Free Absorptive Frequency Selective Surface for Wi-Fi Applications

A compact partially transmissible absorptive frequency selective surface (AFSS) which requires neither surface mount device resistors nor resistive ink is proposed in this communication. The resistor-free AFSS utilizes the lossy characteristic of FR-4 substrate material to achieve the absorption property. The method to efficiently model the AFSS based on physical phenomena has been thoroughly discussed, by which the effect of substrate loss can be predicted accurately. An equivalent circuit model is also presented, and its predicted result agrees well with the full-wave simulation. Furthermore, the fabrication and measurement are also conducted to demonstrate the feasibility of resistor-free AFSS. The highest absorption rate of the AFSS is designed around 2.46 GHz, while at least half-power transmission is guaranteed below 1 GHz. These electromagnetic functions as well as the low fabrication cost and complexity make the resistor-free AFSS a promising candidate for advanced packaging and shielding of mixed signal system.

Convoluted double square: single layer FSS with close band spacings

A novel element provides reflection band ratios as low as 1.1. It is derived from the double square but is less demanding on printing definition. Together, the two elements offer increased flexibility in frequency selective surface design for close band applications. Substrate loss effects are also discussed.

Improved microwave performance on low-resistivity Si substrates by Si/sup +/ ion implantation

Microwave characteristics of spiral inductors on low-resistivity Si substrates have been improved by implanting Si/sub 28//sup +/ ions. Spiral inductors fabricated on these implanted substrates demonstrate better Q-value and microwave performance. The Q-value of inductor enhanced 60% on the implanted substrates than that of low resistivity Si substrates. An equivalent circuit model of inductor has been evaluated to discuss the effect of substrate loss.