Design of millimeter-wave planar antenna arrays with substrate integrated waveguide feeds
Student thesis: Doctoral Thesis
Related Research Unit(s)
The thesis presents a series of planar antenna arrays for emerging millimeter-wave wireless applications. All proposed antennas, which are excited by coupling apertures etched on the copper-clad surface of the substrate integrated waveguide (SIW), exhibit wide bandwidths and good radiation characteristics. Due to the use of the SIW to compose feed networks, low feed network losses and high-gain performance are obtained forthe designed antenna arrays. Moreover, the feeding scheme of the aperture coupling with a two dimensional geometry is easy to realize at millimeter-wave frequencies, which enables the proposed antenna array to be fabricated conveniently by different manufacturing technologies. First, cavity-backed microstrippatch antenna arrays with full corporate SIW feed networks are demonstrated. A prototype of 16 × 16 radiating elements with a SIW to waveguide transition is fabricated by applying standard printed circuit board (PCB) facilities. A gain up to 30.1 dBi with a 3-dB gain bandwidth of 16.1%, an impedance bandwidth of 15.3% for SWR < 2, and symmetrically broadside radiation patterns with -40 dB cross-polarizations are achieved. The performance of the proposed antenna array is also systematically evaluated. The result serves as a reference for designing large antenna arrays operating at millimeter-wave frequencies. Second, a microstrip patch antenna array with an improved wide bandwidth is studied. A novel wideband SIW-fed dual-aperture-coupled microstrip patch antenna is proposed. A single layered SIW feeding network with wideband T-junctions and the wideband radiating element are employed to achieve high-gain and wideband performance simultaneously. The simulated and measured impedance bandwidths of a 4×4 antenna array are 27.5% and 22.6% for |S11| < -10 dB. A gain up to 19.6 dBi and symmetrical unidirectional radiation patterns with low cross polarization are also achieved. Third, anovel perforated dense dielectric (DD) patch antenna array fed by a single-layered SIW feed network is investigated. The proposed antenna array offers advantages of wide bandwidth and good radiation performance and can be fabricated conveniently by standard PCB technology. A 4 × 4 prototype operated at the 60-GHz band is designed, fabricated and measured to demonstrate the design. An impedance bandwidth of 23% for SWR < 2, a gain up to 17.5 dBi with a 3-dB gain bandwidth of 24%, and symmetrical unidirectional radiation patterns with cross polarizations of less than -20 dB are obtained. Fourth, a series of novel SIW-fed aperture-coupled ME-dipole antennas with linearly, circularly and dual-polarized radiations are developed. Compared with reported designs, the proposed designsmaintain the advantages of the ME-dipole antennas, including wide bandwidth, symmetrical E- and H- plane radiation patterns, low backward radiation and high gain, but are easier to realize at millimeter-wave frequencies. By employing the dual-polarized aperture-coupled ME-dipole antenna, a 2 × 2 wideband antenna array working at the 60-GHz band that can generate two-dimensional multi-beams with dual-polarizations is designed, fabricated and tested. A measured impedance bandwidth wider than 21.9% for |S11| < -10 dB and a gain up to 12.5 dBi are obtained. Owing to the superiority of the ME dipole, the radiation pattern of the array is also stable and nearly identical in two orthogonal planes for both polarizations.
- Microwave antennas, Antenna feeds, Design and construction, Antenna arrays