Seamless exploitation of cell‐phone antennas for near‐field WPT by a frequency‐diplexing approach. Issue 5 (24th January 2017)

• Record Type: Journal Article
• Authors: Del Prete, Massimo; Berra, Francesco; Costanzo, Alessandra; Masotti, Diego
• Is Part Of: IET microwaves, antennas & propagation. Volume 11:Issue 5(2017)
• Page Start: 649
• Page End: 656
• Publication Date: 2017-01-24
• Subjects: near‐field communication -- mobile handsets -- mobile antennas -- radiofrequency power transmission -- inductive power transmission -- directive antennas -- UHF antennas -- monopole antennas -- multifrequency antennas -- microstrip antennas -- antenna feeds -- data communication; cell‐phone antenna seamless exploitations -- near‐field WPT -- frequency‐diplexing approach -- portable devices -- communication antennas -- bidirectional near‐field wireless recharging -- GSM 900/1800 -- far‐field communication -- printed monopole antenna -- dual‐band antenna -- faced antenna -- two‐port network -- full‐wave analysis -- frequency‐selective three‐port network -- data communication -- power transfer efficiency -- far‐field radiation -- RF‐to‐RF power transfer efficiency -- rectifier dc output -- RF‐to‐dc‐link efficiency -- link input power port -- receiving power port -- frequency 433 MHz -- efficiency 15 percent to 40 percent; Microwaves -- Periodicals; Microwave antennas -- Periodicals; Antennas (Electronics) -- Periodicals; Radio wave propagation -- Periodicals; Microwave communication systems -- Periodicals; 621.381305
• DOI: 10.1049/iet-map.2016.0281
• Languages: English
• ISSNs: 1751-8725

Abstract

Abstract : This paper introduces a novel solution for portable devices to exploit their existing communication antennas for bi‐directional near‐field wireless re‐charging, without compromising their far‐field properties. To demonstrate the concept, the radio‐frequencies (RF) 900/1800 MHz and 433 MHz are adopted for the far‐field communication and for the near‐field wireless recharging, respectively. First, a pair of faced, dual‐band, printed monopoles is characterized as a two‐port network over the bands of interest at several distances. Then, each antenna is fed by a frequency‐selective three‐port network, designed to simultaneously ensure data communication at the higher frequencies and wireless re‐charging at the lower one. In this way, the combined far‐field and near‐field operations of the resulting four‐port network can be optimized. A proof‐of‐concept prototype has been characterized, showing ports isolation higher than 20 dB and RF‐to‐RF power transfer efficiency between 15% and 40% for variable faced antennas distance. When a rectifier is connected to the receiving power port, the measured RF‐to‐dc link efficiency varies between 9% and 20%, with portable devices located 1 and 2 centimeters apart, and the transmitted power is 10 dBm. The simultaneous high frequency communication is verified with slightly reduced performance.