Compact inline substrate integrated waveguide filter with enhanced selectivity using new non‐resonating node

Abstract

A high selective inline substrate integrated waveguide (SIW) filter based on novel stepped-impedance non-resonating node (NRN) is presented. The stepped-impedance NRN is realised by inserting a stepped-impedance substrate integrated coaxial line resonator into the volume of a third-order SIW filter. It introduces extra signal transmission path between source and load. Thus, one more transmission zero (TZ) is produced compared with conventional NRN that further improves the selectivity of the filter. Also, the proposed filter achieves a compact circuit size as the stepped-impedance NRN is embedded in the SIW cavity without occupying extra layout. To validate the proposed concept, a prototype filter with two TZs locating at both the lower and upper stop-bands, is designed, fabricated and measured. The measured results are well consistent with the simulation ones.

Multitransmission Zero Dual-Band Bandpass Filter Using Nonresonating Node for 5G Millimetre-Wave Application

“…The susceptance of the NRN is JNRN. If the voltage VNRR is eliminated from (12), by using the last row, we get the new matrix equation:…”

“…In [11], special coupling topology is designed to introduce electromagnetic coupling between nonadjacent resonators. An SIW filter with etched capacitive slots at the coupling region is proposed in [12]. These slots could create a negative coupling coefficient but also result in a higher radiation loss.…”

Compact wideband substrate integrated waveguide bandpass filter for X/Ku‐bandapplication

“…3 In recent years, many researchers have drawn attention to the development of SIW wideband bandpass filters with low insertion loss, large bandwidth and miniaturization. [4][5][6][7][8][9][10][11][12][13][14][15][16] In Reference 4, a non-physical crosscoupling in the SIW cavities has been introduced for the design of a SIW BPF. Although the filter is lightweight, it suffers from poor bandwidth.…”

Substrate integrated waveguide filter based on novel coupling-enhanced semicircle slots for 5G applications

“…Substrate integrated waveguide (SIW) technology can be used to design small and low-cost cavity filters at millimeter-wave frequency using coupling matrix [19,20]. The most common method for controlling the resonators' coupling in an SIW filter is to adjust the coupling iris width in the via wall between two resonant cavities [21,22,23,24,25,26]. The coupling should be stronger with a larger iris width.…”