Dong-Fang Guan

An SIW-Based Large-Scale Corporate-Feed Array Antenna

A 16 × 16 substrate-integrated waveguide (SIW) cavity-backed array antenna is proposed in this paper. The array consists of two layers. The top layer employs novel SIW-based subarrays with a compact size. The bottom layer is an 8 × 8 SIW corporate-feed network to feed the subarrays. The Chebyshev amplitude weighting is employed in the feed network, which substantially reduces the side lobe level (SLL). The array antenna is fabricated using low-cost printed circuit board technology. The experimental results show that the proposed array antenna has a large bandwidth of 15% from 18.5 to 21.5 GHz with a peak gain of 29.1 dBi at 20.5 GHz. Across the entire band, high radiation efficiency above 62% and a low SLL below -17 dB are realized. The design principle can be used as a guidance for largescale planar array antenna design and the proposed antenna can be used as a receiving antenna located on the ground in satellite communication systems.

Novel SIW Cavity-Backed Antenna Array Without Using Individual Feeding Network

Substrate integrated waveguide (SIW) cavity-backed antenna arrays have advantages of low-profile, high-gain and low-cost fabrication. However, traditional SIW cavity-backed antenna arrays usually load with extra feeding networks, which make the whole arrays larger and more complex. A novel 4 × 4 SIW cavity-backed antenna array without using individual feeding network is presented in this letter. The proposed antenna array consists of sixteen SIW cavities connected by inductive windows as feeding network and wide slots on the surface of each cavity as radiating part. Without loading with extra feeding network, the array is compact.

Broadband High-Gain SIW Cavity-Backed Circular-Polarized Array Antenna

A circularly polarized (CP) 4 × 4 array antenna based on substrate integrated waveguide (SIW) technology is presented. Circular polarization is achieved by applying the sequential rotation technique (SRT) with a well-designed sequential feed network and linear-polarized array elements. The proposed 4 × 4 array has a wide axial ratio (AR) bandwidth of 14% from 18.3 to 21.1 GHz with gain >13 dBic. Then, the array is expanded to achieve higher gains. A 16 × 16-element array is designed, fabricated, and tested. Test results show that the 16 × 16 array has an AR bandwidth of 13.8% from 18.5 to 21.25 GHz and a peak gain of 25.9 dBic at 20.5 GHz.

A Hybrid SIW and GCPW Guided-Wave Structure Coupler

Since substrate integrated waveguide (SIW) is not directly compatible with active circuits, additional transitions to planar transmission lines are indispensable. In this letter, a novel hybrid SIW-CPW structure coupler applying an antenna feeding network is presented. SIW is used as the radiating portion while coplanar waveguide (CPW) is the input matching portion that is connected directly to the active circuits. Without any transition structure, the whole system can be more compact. In addition, this hybrid coupler has a relative bandwidth of over 30% with the broadband amplitude and phase balance characteristic of CPW.

Compact SIW Annular Ring Slot Antenna With Multiband Multimode Characteristics

A substrate-integrated waveguide (SIW) cavity-backed annular ring slot antenna with multiband multimode characteristics is proposed in this communication. The antenna consists of an SIW cavity and an annular slot on top surface as the radiator. Two patch-like radiation patterns and one monopolar radiation pattern at three different frequencies are excited by the single fed antenna. Moreover, each operating frequency can be individually adjusted. A prototype is fabricated and measured to validate the theoretical analysis. Good agreement between the simulated and measured results of the input reflection coefficients and radiation patterns is achieved. Compared with other designs, the proposed antenna has features of simple structure, multiband multimode and frequency-tunable characteristics.

High-Gain SIW Cavity-Backed Array Antenna With Wideband and Low Sidelobe Characteristics

A 16 ×16 gain-high substrate integrated waveguide (SIW) cavity-backed slot array antenna with wideband and low sidelobe level (SLL) characteristics is proposed in this letter. The array is fed by an 8 ×8 SIW corporate-feed network in the bottom layer. A series of 2 ×2 compact SIW sub-arrays are employed as radiating elements in the top layer. The 45° linearly polarized technique is used in the design of radiating slots, which can substantially suppress the SLL of the array. Meanwhile, benefiting by the broadband merit of the sub-array and the corporate-feed structure, the proposed array has a broad bandwidth. A prototype is fabricated to verify the array properties. The measured bandwidth is 12% from 19 GHz to 21.5 GHz and the maximal gain can reach up to 29 dBi. Besides, the low sidelobe characteristic is achieved and the measured first SLLs are below -24 dB across the entire work band.

Hybrid SIW-GCPW Narrow-Wall 3 dB Coupler

Abstract In this paper, a novel narrow-wall double-slot 3 dB coupler is proposed. Efficient coupling is achieved between a substrate integrated waveguide (SIW) and a ground coplanar waveguide (GCPW). Such hybrid integrated coupler combines the low-loss property of SIW with the flexibility of CPW. The coupling mechanism between TE10 mode of SIW and TEM mode of GCPW is studied. According to the provided theory, a 3 dB coupler is designed and fabricated operating around 18 GHz and achieves a relative bandwidth of 10%. The measured results are in agreement with the simulated ones.

A forward narrow-wall double-slot 3 dB coupler based on hybrid HSIW/GCPW guided-wave structure

Based on a novel hybrid guided-wave structure of half-mode substrate integrated waveguide (HSIW) and ground coplanar waveguide (GCPW), a forward narrow-wall double-slot 3 dB coupler with the center operating frequency of 18 GHz is proposed. The narrow-wall double-slot coupling mechanism between TE10 mode of SIW and TEM mode of GCPW is studied and efficient coupling is achieved by using triangle-shaped slots. Such coupler takes the advantages of low profile, low insertion loss of HSIW and flexibility of GCPW. The coupler is fabricated and the measured results are in agreement with the simulated ones. A relative bandwidth over 20% is achieved with 0.5 dB amplitude imbalance excited at different ports.

A Novel 2-D Multibeam Antenna Without Beamforming Network

A novel design of multibeam array antenna without feeding network is presented in this communication. This array antenna consists of 3×3 microstrip patches as radiators. In this design, a feeding network is avoided where each patch is fed by a probe. Furthermore, whatever patch is excited, the input power can be coupled to all patches through four microstrip lines located between the radiating elements. In addition, nine radiation beams can be implemented depending on different field distributions that are generated by exciting each patch individually. The proposed antenna has a simple single-layered structure and does not suffer from a complex feeding network compared with traditional multibeam antennas. The experimental results demonstrate that the scanning ranges of the nine beams are ±24° and ±45° in the vertical and horizontal directions, respectively. Moreover, measured gain for the nine beams of the implemented antenna varies from 9.06 to 10.45 dBi.

Hybrid SIW-GCPW Cruciform Directional Coupler

Abstract A novel hybrid SIW-GCPW cruciform coupler is proposed and demonstrated. This coupler consists of a cross-over of substrate integrated waveguide (SIW) and ground coplanar waveguide (GCPW) in a square junction. Efficient coupling is achieved by adding two inductive metallic posts on the diagonal line of the junction. Taking advantages of low profile, low insertion loss of SIW and flexibility of GCPW, this coupler structure can be integrated in microwave and millimetre-wave planar circuits, especially in beam-forming networks. A 3 dB coupler is designed and fabricated operating around 33 GHz. Characteristics of 15 dB isolation between the input port and isolated port are achieved over 18% bandwidth. Design considerations and simulated as well as measured results are presented and discussed.