2.45 GHz wearable rectenna array design for microwave energy harvesting

Abstract

This paper presents a design of a wearable textile microstrip patch rectifying antenna (rectenna) array operating for wireless body area network (WBAN) at the center frequency, <em>f<sub>c</sub></em> of 2.45 GHz. Precisely, jeans or denim with the relative permittivity, <sub> </sub>= 1.70 and thickness of 1.00 mm is chosen as a substrate attached to SheildIt Super as a conductive material with the thickness, <em>h</em> of 0.17 mm and conductivity of 6.67 10<sup>5</sup> S/m, respectively. In the first stage, a microstrip patch antenna array layout with the inset fed technique is designed and simulated by using the Keysight Advanced Design System (ADS) software. In the second stage, a wearable textile microstrip patch antenna array is fabricated, integrated, and hidden inside the jeans fabric. In the third stage, the rectifier circuit layout on the flame retardant-4 (FR-4) printed circuit board (PCB) with the dielectric constant, = 4.7, thickness, <em>h</em> = 1.6 mm, and loss tangent, <em>δ</em> = 0.018 that can generate radio frequency-direct current (RF-DC) conversion is designed and simulated using the ADS software Each simulation result and fabrication measurement shows that the designed antenna array characteristics are suitable for an industrial, scientific, and medical radio (ISM) band by having the reflection coefficient, <em>S</em><sub>11</sub> less than -10 decibel (dB) at the respective resonant frequency, <em>f<sub>r</sub>.</em> Moreover, through simulation, the output DC voltage for the bridge rectifier circuit is from 132 mV to 5.01 V with the corresponding power conversion efficiency (PCE) between 3.48% and 50.20% whereas for the voltage doubler rectifier, the output DC voltage is from 417 mV to 2.91 V with the corresponding PCE between 34.78% and 53.56%, respectively.

A new structure of a wide band bridge power limiter

“…However, it is possible to generate the necessary DC biasing current by choosing Zero-Bias diodes [21,22] and using a detector diode as shown in Figure 2. The detector diode will transform a part of incident signal to DC current as used in rectenna systems [23,24]. On the other hand, the return DC current is ensured by an RF Choke or by the limiter diode itself.…”

“…The HSMS286x family data sheet shows that these diodes are optimized for RF applications from 915 MHz to 5.8 GHz. They are used for large signals detection, modulation and rectification of RF signals [20,24]. Since Advanced Design System (ADS) software is suitable for RF design and natively contains the different HSMS286x families in its library, we used it to validate and simulate the proposed circuit.…”

Designs of rectangular-shaped planar Inverted-F antennas at mobile operating frequencies with different ground plane techniques

“…where c, f and are the speed of light, operating frequency and effective relative permittivity of the substrate, respectively. The effective relative permittivity of the substrate, can be determined from (3) [11][12][13][14]:…”

Design of 2.45 GHz High-Efficiency Rectifying Circuit for Wireless RF Energy Collection System

“…A wireless RF energy collection system is the form of collecting RF energy at different frequencies in the natural environment through a receiving antenna first, and then converting into DC energy through a rectifying circuit. As a new energy collection technology, it has great application value in the fields of low-power wireless sensor networks [ 2 ], biomedical sensors [ 3 , 4 ], Internet of Things mobile terminal devices [ 5 , 6 , 7 ], intelligent wearable devices [ 8 , 9 , 10 , 11 , 12 ], and so on. The traditional wireless RF energy collection system mainly includes an RF signal source, transmitting antenna, receiving antenna and rectifying circuit.…”