Perforated microstrip structure for miniaturising microwave devices

The perforated slow-wave microstrip is proposed for high-frequency microwave devices and characterised experimentally and theoretically up to 7 GHz. The perforated structure is realised with a periodic-inductive-section-maintained uniform edge-shape. The slow-wave factor is demonstrated to be 1.2 times larger than that of a conventional microstrip over a wide frequency range. The perforated slow-wave microstrip shows reduction of physical length and superior quality-factor. The proposed structure is easier to fabricate than other slow-wave structures, which require multilayer substrates.