This paper presents design of the novel alternating-phase fed array with linearly slot arrangement for grating lobe suppression. Slots at the center of the broad wall are excited by the inductive wall and the reflection is suppressed by the capacitive wall at each slot. Then, the prototype array with 16 slots on each waveguide is tested at 25 GHz. Good radiation pattern with broadside radiation of the slot array is measured at the design frequency. Validity of the slot array design is confirmed.
Abstract A one‐point back‐feed type circularly polarized microstrip disk antenna is investigated. To establish a design procedure, (1) the operating condition for circular polarization is studied and design formulas and data are presented and (2) the fabrication and radiation characteristics of arrays consisting of the present circularly polarized disk antenna element are discussed. It is demonstrated that this class of antennas can serve as a useful form of circularly polarized array element. Further, in order to analyze the mutual coupling of such antenna elements, the resonance and inter‐element mutual admittance of an array consisting of two disk antennas located on the same plane are determined. The fundamental information on the mutual coupling thus obtained is presented for a design aid. Using these results, a circularly polarized array is realized with good axial ratio and boresight ratio less than 0.5 dB.
A novel CPW fed stacked circular MSA with the DGS slab has been presented. Bandwidth and gain of the multiband planar antenna are enhanced. The DGS slab has a function to separate the typical frequencies of the stacked CMSA and to improve the impedance matching as an impedance transformer. Experiments were carried out to verify the results predicted in the simulation. Good agreement between the measured and simulated data has been confirmed. Thus, the proposed antenna can be considered as an alternative model for a multiband planar antenna.
It is well known that a stacked microstrip antenna enables the construction of a broadband planar antenna. A coplanar waveguide (CPW) is also used as an efficient feeding system for a microstrip antenna (MSA), since it enables the realization of series and shunt connections of active devices without through-holes. For this reason, a stacked microstrip antenna fed by a coplanar waveguide with dogbone slot (stacked CPW-MSA) is proposed, and its design technique and radiation properties are presented. Various experiments were carried out in the C-band to estimate the performance of the antenna. A broadband bandwidth of 21% (VSWR /spl ges/ 2.0) was achieved using the antenna. The simulated results obtained from the IE3D simulator agreed well with the experimental results. Therefore, this type of stacked CPW-MSA is considered to be an effective model for a broadband planar antenna.
This paper demonstrates a novel multiband rhombic microstrip antenna (MSA) with multiple slots printed on a single-layer PTFE substrate. The antenna is fed by a coplanar gap coupled with a V-shaped patch. Three inverted V-shaped slots are assumed on the rhombic patch and hence four resonant frequencies are obtained. Broadside radiation patterns and gain of over 5.0 dBi are also obtained. Experiments were carried out to verify the results estimated by IE3D simulator. Good agreements between simulated and measured results are confirmed. To further evaluate the performance, rhombic MSA with six inverted V-shaped slots is also investigated. Again, this antenna model accomplishes excellent multiband performances over the seven observed frequencies. Thus, the rhombic MSA with multiple slots is well suited as an alternative design for a multiband planar antenna.
