That or using discontinuities in impedance intentionally. I've designed and had built a handful of successful UHF planar PCB filters using Sonnet. In a lot of them I use very small changes in trace width as the place to put resonating elements. ie, http://superkuh.com/stepped-impedance-bandstop-filter.html
The difference between square corners and compensated is real. And it gets more real if you're working in generic FR4 with 1.6mm thickness and 2-3mm wide traces for the sweet spot between 50 and 75 ohms.
The difference between square corners and compensated is real. And it gets more real if you're working in generic FR4 with 1.6mm thickness and 2-3mm wide traces for the sweet spot between 50 and 75 ohms.