Synthesis and design of in-line N-order filters with N real transmission zeros by means of extracted poles implemented in low-cost rectangular H-plane waveguide - Montejo-Garai, JR; Ruiz-Cruz, JA; Rebollar, JM; Padilla-Cruz, MJ; Onoro-Navarro, A; Hidalgo-Carpintero, I (Ieee Transactions On Microwave Theory And Techniques, 2005)