Dual-Polarized Stacked Patch Antenna for Wireless Communication Application and Microwave Power Transfer

In this paper, a dual-polarized stacked patch antenna for wireless communication and microwave power transfer is proposed. The stacked antenna consists of four rectangular apertures that are etched on the ground plane and four identical cross-placed coupling strips that are set on the upper layer of the ground plane, which are used to excite the top-layer patches. The presented stacked patch antenna was designed as a completely symmetric structure except for the feeding network, resulting in a simple structure and the same radiation patterns for the two polarized ports. The proposed antenna operates at around 5.8 GHz, and the simulation and measured results show that it has a gain of 8.5 dBi and an isolation of 25 dB. The measured antenna efficiency of the two polarized ports at 5.85 GHz was 89.2% and 88.6%, respectively. Finally, a rectifying circuit was designed, and the maximum measured conversion efficiency of the two polarized rectenna was 63.5% and 62.7%, respectively.

Compact Dual-Band Circularly Polarized Stacked Patch Antenna for Microwave-Radio-Frequency Identification Multiple-Input-Multiple-Output Application

A compact, low-profile, two-port dual-band circularly polarized (CP) stacked patch antenna for radio-frequency identification (RFID) multiple-input-multiple-output (MIMO) readers is proposed, which employs the shared-aperture technique. The proposed antenna adopts a 1.524 mm thickness Rogers Ro4350b substrate with relative permittivity of 3.48. Two pairs of isolated ports are working at two microwave- (MW-) RFID bands (2.4–2.485 GHz and 5.725–5.875 GHz) with high port isolation of 25 dB and 30 dB, respectively. A shared metal slot layer is designed to separate two feeding structures of the lower band and upper band for port isolation enhancement as well as saving space. Corner-truncated square slot and patch configurations have been designed to obtain CP modes. In the lower and upper MW-RFID bands, the relative impedance bandwidths are 12.2% and 5.7%, and the maximum realized gains are higher than 7.3 dBic. Moreover, two-element configurations have been combined for an RFID MIMO system that occupies a dimension of 119 mm × 119 mm × 12.9 mm. The MIMO antenna performance of envelope correlation coefficient (ECC) is lower than 0.03, and diversity gain is close to 10 dB.