Hybrid HMSIW Cavities Antenna With a Half-Pentagon Ring Slot for Bandwidth Enhancement

Abstract

A substrate-integrated waveguide (SIW) antenna is an implementation of a waveguide antenna in a microstrip antenna. The microstrip antenna, as a low-profile antenna, suffers from narrow impedance bandwidth. This paper proposes a novel bandwidth enhancement method for solving a narrow impedance bandwidth. Bandwidth enhancement was achieved by using quad-resonant frequencies. The quad-resonant frequencies are resulted from the hybrid half-mode substrate-integrated waveguide (HMSIW) cavities between the inner and outer cavities. The inner HMSIW cavity has a half-pentagon ring slot that disturbs the TE 101−inner , TE 102−inner , TE 202−inner , and TE 103−inner modes, whereas the outer HMSIW cavity consists of two outer quarter-mode substrate-integrated waveguide (QMSIW) cavities. The outer HMSIW cavity generated the TE 102−outer and TE 202−outer modes. The hybrid cavities were fed simultaneously using a port with a quarter-wavelength feed transmission line. The hybrid HMSIW cavities generated resonant frequencies that were close to each other. Additionally, this method was applied to the X-band frequency with a low-profile substrate. The simulated impedance bandwidth and peak realized gain was 33.86% (8.98 − 12.64 GHz) and 7.97 dBi, while the measured impedance bandwidth and peak gain were 31.83% (9.14 -12.6 GHz) and 7.62 dBi, respectively. Strong agreement was observed between the measurement and simulation results.INDEX TERMS Bandwidth enhancement, hybrid cavities, quad-resonant, a half-pentagon ring slot, halfmode substrate-integrated waveguide antenna.

Bandwidth enhancement for QMSIW antenna by using dual cavity and triangle slot

“…Many researchers proposed bandwidth enhancement methods for solving the narrow bandwidth like coupling techniques [16], [17], modified slot designs [18]- [21], or dual-cavity configurations [22], [23]. The coupling technique occurs between at least two adjacent sub-cavities.…”

“…Ref. [22] and [23] use the dual-cavities SIW method for resulting bandwidth enhancement. The broadband bandwidth enhancement (31.83%) is achieved by using this method.…”

Bandwidth Enhancement for Half Mode Substrate Integrated Wave guide Antenna using Defected Ground Structures

“…Again, the subcavities of SIW with a dominant mode suffer the narrow bandwidth [11]- [13]. Some research is concerned to enhance impedance bandwidth by using fraction mode [14], coupling [15], dual cavity [16], [17], or modified slot [18], [19]. All of this research has succeeded in improving impedance bandwidth by generating hybrid, triple and quad resonance.…”