Kuan Deng

Analysis and Experiments of Compact Folded Substrate-Integrated Waveguide

The novel folded substrate-integrated waveguide (FSIW) is 50% narrower than the substrate-integrated waveguide, but both have similar propagation characteristics. This paper derives the analytical formulas of propagation and cutoff characteristics of the FSIW, as well as the formulas to calculate the width and gap of the central metal septum. Very good agreements (<2% error) are observed among the results of the theoretical formulas, numerical simulations, and hardware experiments over wide frequency and parameter ranges.

Compact Planar Magic-T Using E-Plane Substrate Integrated Waveguide (SIW) Power Divider and Slotline Transition

A novel planar magic-T using an E-plane substrate integrate waveguide (SIW) power divider and a SIW-slotline transition is proposed in this letter. Due to the metal ground between the two input/output ports, the E-plane SIW power divider has a 180° reverse phase characteristic. A SIW-slotline transition is utilized to realize the H-plane input/output port of the magic-T. Good agreement between the measured and simulated results indicate that the planar magic-T has a fractional bandwidth (FBW) of 18% (13.2-15.8 GHz), and the amplitude and phase imbalances are less than 0.24 dB and 1.5°, respectively.

Microstrip dual-band bandstop filter of defected ground structure and stepped impedance resonators

This article presents a compact microstrip dual-band bandstop filter (BSF), in which one λg/4 defected ground structure (DGS) pair is utilised to realise one stopband while two stepped impedance resonators (SIRs) help obtain another stopband and suppress the spurious harmonics. The design strategies and the equivalent circuits are introduced in detail. The measured results indicate 43.8% and 18.7% fractional bandwidth in the two stopbands (2.4 GHZ and 5.2 GHz) respectively, and the return loss is greater than 15 dB in the whole passband. In addition, size reduction can be conveniently achieved by adjusting the length of the SIRs and DGS.

Characteristics of H-Plane Rectangular Waveguide Bends Integrated into Thin Substrate

In multilayer microwave integrated circuits such as low-temperature co-fired ceramics (LTCCs) or multilayer printed circuit boards (PCBs), waveguide-like structures can be fabricated in planar form by using periodic metallic via holes called substrate integrated rectangular waveguides (SIRWs) [1]-[2]. The SIRW structures can largely preserve the well-known advantages of conventional rectangular waveguides; it is useful for the design of millimeter-wave circuits such as filters, resonators, and antennas etc.

Equivalence of Short Circuits between SIRW with Cylinder Wall and Regular Waveguide with Solid Wall

In this paper, the formula of equivalence of short locations of SIRW (with shorting cylinder wall) from the rectangular waveguide (RW) (with shorting solid wall) has been obtained. The similarity between components of the plane propagation-constant in the waveguide means that the formulas of short location are directly converted from the formula of width equivalence of SIRW from RW, the width formula has been verified to be accurate. The results have shown that, the width equivalence between SIRW and RW depends on the width of SIRW, cylinder radius and separation, being independent with frequency. However, the location equivalence from cylinder short wall to solid short wall depends on the frequency, although the dependence is still small. To end, it may be noted that the formulas apply only to quasi-static separation W of the cylinders along the shorting wall, i.e., W les lambdag/20. If the cylinder radius R < W/4, there will be power leakage out of the SIRW short. This leakage is to be studied