Dual-mode Substrate Integrated Waveguide Research Articles

MINIATURIZED DUAL-MODE SUBSTRATE INTEGRATED WAVEGUIDE (SIW) BAND-PASS FILTERS LOADED BY DOUBLE/SINGLE T-SHAPED STRUCTURES

A new class of miniaturized dual-mode substrate inte- grated waveguide (SIW) band-pass fllters is proposed, which are loaded by double/single T-shaped structures. By introducing a double T- shaped structure in original dual-mode SIW band-pass fllter, the reso- nant frequency is lowered from 9.46GHz to 8.91GHz due to the longer efiective length. The introduced single T-shaped structure performs an even lower resonant frequency of 6.88GHz for the same reason. Compared with dual-mode band-pass fllters in references, the proposed dual-mode SIW band-pass fllters with double/single T-shaped struc- tures have the advantages such as compact size (like microstrip dual- mode fllters) and high Q factors (like SIW dual-mode fllters). The proposed fllters are fabricated and measured, and the experimental results are in good agreement with simulated ones.

MINIATURIZED SUBSTRATE INTEGRATED WAVEGUIDE DUAL-MODE FILTERS LOADED BY A SERIES OF CROSS-SLOT STRUCTURES

A family of miniaturized substrate integrated waveguide (SIW) dual-mode fllters with a series of cross-slot structures etched on the waveguide surface are investigated and presented. By introducing the series of cross-slot structures: pure cross-slot, T-shaped loaded cross-slot and H-shaped loaded cross-slot in original dual-mode SIW fllters, size reductions of 22.15%, 30.56% and 56.25% are achieved, respectively. Moreover, the proposed family of SIW dual-mode fllters can produce two controllable transmission zeros. Compared with SIW dual-mode fllters in references and original fllter, proposed fllters exhibit compact size while retain good performance of bandwidth and minimum insertion loss. To verify the presented design, three SIW dual-mode fllters are fabricated on the standard printed circuit board process. The measured results are in good agreement with the simulation.

A Millimeter-Wave Sub-Harmonic Self-Oscillating Mixer Using Dual-Mode Substrate Integrated Waveguide Cavity

This paper presents a novel sub-harmonic self-oscillating mixer (SOM) topology that makes use of the transmission characteristics of two operating modes in a substrate integrated waveguide (SIW) cavity. The SOM circuit consists of a dual-mode SIW bandpass filter, a common source heterojunction field-effect transistor, and a low-pass filter. The fundamental mode ( H 101) of the SIW cavity is used for RF mode operation, while the H 202 mode is used for local oscillation. A K a-band experimental prototype has been designed and fabricated to demonstrate and validate our proposed circuit concept. The measured power levels of the self and second harmonic local oscillator signals are about 8.5 and -3 dBm, respectively. The mixer, implemented as a down-converter, achieves a 12-dB conversion loss and an IF phase noise of -81 dBc/Hz at 100-kHz offset with a 34-GHz RF input.

Development of Millimeter-Wave Planar Diplexers Based on Complementary Characters of Dual-Mode Substrate Integrated Waveguide Filters With Circular and Elliptic Cavities

A novel high-performance millimeter-wave planar diplexer is developed based on the complementary characters of substrate integrated waveguide (SIW) dual-mode filters with circular and elliptic cavities by making the tradeoff between the isolation, insertion loss, and selectivity. The responses of the dual-mode SIW circular and elliptic cavities are first investigated. It can be found that the upper side response of the circular cavity and the lower side response of the elliptic cavity are very steep. The diplexers with high isolation performance are then designed based on the complementary response characters of circular and elliptic cavities. A diplexer with two dual-mode SIW circular and elliptic cavities is designed and fabricated with a normal printed circuit board process. The measured insertion losses are 1.95 and 2.09 dB in the upper and lower passbands centered at 26 and 25 GHz with the fractional bandwidths of 5.2% and 5.4%. The isolation is lower than - 50dB

Symmetric dual-mode filter based on substrate integrated waveguide (SIW)

A planar four-pole dual-mode filter with symmetric transmission response based on substrate integrated waveguide (SIW) is proposed. The filter centered at 10 GHz, consisting of two TE102–TE201 dual-mode SIW cavities, is implemented in a single layer substrate by PCB process. A linear microstrip taper is used to implement the transition between 50 Ω microstrip and SIW. The measured results are in agreement with simulated results.

Substrate integrated waveguide (SIW) asymmetric dual-mode filter and diplexer

Substrate integrated waveguide (SIW) can be used to implement high Q waveguide components with the same easy and low-cost fabrication process as planar circuits. In this paper two inline three-pole dual-mode filters with asymmetric transmission response based on SIW are presented. These two filters, consisting of a TE102-TE301 dual-mode SIW cavity and a TE101 mode SIW cavity, are centred at around 10 GHz with a transmission zero on the left of the passband and the right of the passband, respectively. Based on the two kinds of three-pole deal-mode filters, a diplexer with isolation better than 35 dB is developed. A linear microstrip taper is used to implement the transition between microstrip and SIW. The measured results agree with simulated results.