JP3246306U - IMPORTANT ANTENNA FOR IOT-BASED HEALTH MONITORING DEVICES - Google Patents

Abstract

An implantable antenna for an IoT-based health monitoring device is provided. The implantable antenna 100 includes a parasitic radiating patch 104, a radiating patch 106, a feed line 108 on the front side of a substrate 102, and a ring-shaped slotted ground 110 on the back side of the substrate. This configuration stabilizes the impedance of the antenna 100, making it suitable for medical applications. (Selected Figure)

Description

The present disclosure relates to the field of antennas for wireless communications. More specifically, the present disclosure relates to an implantable antenna for an IoT-based health monitoring device.

Through the rapid improvement of low-power, miniaturized electronic devices and sensors, implantable medical devices (IMDs) have attracted much interest from researchers. Potential applications of IMDs include neurostimulation, therapeutics, disease diagnosis and treatment, and deep body communication, as well as drug delivery devices with a high level of precision. Antennas are an important part of implantable medical devices for wireless biotelemetry with external monitoring devices. Therefore, implantable devices require antennas with higher gain, lower specific absorption rate, and unidirectional radiation pattern.

However, in the complex and lossy environment of biological tissue, it is difficult to maintain stable radiation characteristics and impedance matching in a compact antenna structure.

There are many prior art techniques that attempt to solve the problems mentioned above. For example, EBGs and reflector surface structures reduce the absorption of EM waves in biological tissue, which increases the cost and complexity of the antenna.

Another conventional technique is to obtain stacks and parasitic patches. Such techniques are used to achieve a wider impedance bandwidth. However, multi-layer structures are required, which increases the surface current losses.

Another conventional technique is pin shorting. Such a technique is used to minimize the size of the antenna, but it narrows the bandwidth frequency spectrum.

Therefore, an alternative is needed to eliminate the aforementioned objectives.

(Device Overview)
The present disclosure discloses an implantable antenna 100 comprising a parasitic radiating patch 104 on the front side of a substrate 102, a radiating patch 106, a feed line 108, and a ring-shaped slotted ground 110 on the back side of the substrate. Such a configuration makes the impedance of the antenna 100 stable and applicable for medical applications.

(Advantageous Effects of the Device)
The present disclosure discloses an embedded antenna having the following advantages:
(1) Very compact size (10 mm × 10 mm) on a thin flexible substrate RO 3010 with a thickness of 0.25 mm.
(2) Triple-band resonance at 0.86 GHz ISM band, 1.43 GHz WMTS band, and upper UWB from 2.6 to 6.0 GHz supports various communication standards with IoT-based health monitoring IoT devices.
(3) Good impedance matching with wide bandwidth of 116 MHz, 120 MHz, and 3.6 GHz for the three operating bands.
(4) Excellent gain of -26 dBi, -23 dBi, and -16 dBi with broadside-like radiation characteristics.
(5) Suitable for internal use.
(6) Low SAR of 0.534 W/Kg., 0.653 W/Kg., and 0.529 W/Kg. for an input power of 10 mW.

A schematic diagram of the front side of the substrate 102 of the embedded antenna 100 is disclosed. A schematic diagram of the backside of the substrate 102 of the embedded antenna 100 is disclosed.

(Description of the embodiment)
FIG. 1 discloses the front side of the substrate 102 of the implantable antenna 100. On the front side, the implantable antenna 100 includes a parasitic radiating patch 104, a radiating patch 106, a feed line 108 on the front side of the substrate 102, and a ring-shaped slotted ground 110 on the back side of the substrate 102. To use the antenna in biological tissue, the radiator and ground are covered with a dielectric material layer (RO 3010). This isolates the conductor part of the antenna from the lossy tissue layer and also helps to lower the resonant frequency. The design evaluation of the proposed structure to achieve broadband is described in three steps. First, the length and width dimensions of the radiator are estimated according to the lowest resonant frequency of the 0.868 GHz ISM band by the antenna design equation in free space. To obtain multiple resonant bands, an asynchronous-meandered radiator and an open-ended square loop ground plane are designed. To obtain resonance in the WMTS band, a three-slot meandered element is added to increase the length of the radiator. Such modifications have a significant impact on the performance of the antenna. The middle band is tuned to the desired range. An inverted U-shaped parasitic resonator is placed around the heat sink. The coupling effect between the parasitic resonator and the heat sink excites the resonance modes at 2.7 GHz and 3.05 GHz. As a result, a compact triple-band antenna with an open-ended square ring ground, a parasitic resonator, and a meandered patch embedded in it establishes the necessary functions for the biotelemetry system.

A numerical tissue model is designed to embed the antenna 100 in muscle tissue at a depth of 7 mm. A prototype for tri-band implantation is designed with a defected ground structure and an unsynchronized serpentine slot. The antenna radiator is modified stepwise to achieve triple resonant frequencies as shown in Figures 1 and 2. A superstrate layer is added to the conductor section to isolate the antenna from body tissue. The simulator obtains the characteristics of the antenna 100 adapted to the biological environment in the 0.86 GHz ISM band, the 1.43 GHz WMTS band, and the 2.6-6.0 GHz upper UWB.

The present disclosure is beneficial for medical applications.

Claims (1)

An embedded antenna 100 comprising a parasitic radiating patch 104, a radiating patch 106, a feed line 108 on a front surface of a substrate 102, and a ring-shaped slotted ground 110 on a rear surface of said substrate 102.