For most wearable sensors, antennas are critical system components enabling wireless connectivity. For IoT applications, embedding antennas into garments turns the fabric into a smart interface capable of receiving and transmitting information for between the wearer and the network. Antennas used in wearables must be thin, robust, lightweight, resistant to harsh daily usage and, cost-effective to manufacture and commercialize. Some examples of antennas used in wearables are as follows:
- VHF/UHF wearable antennas are most commonly used in professional mobile radio communications for soldiers, emergency operators and law enforcement.
- For soldier vests, police armor, and other law enforcement & emergency personnel, helmet antennas with narrow-band tactical satellite communications operate at 300MHz & wearable antennas for satellite-based search-and-rescue systems operate at 406MHz.
- At higher UHF bands (around 868MHz), wearable antennas have been proposed for remote health monitoring systems, environmental monitoring for rescue operators, security systems, portable short range radars for hazard monitoring, as well for RF energy harvesting systems. Several antenna designs have been proposed for medical applications in the industrial, scientific and medical (ISM) and UHF bands.
- Both printed and textile wearable antennas operating at the UHF RFID 840-960MHz band can be used for remote wireless identification and tracking.
While innovation in wearable technology has taken large strides, there is still much research & development to be desired in this field. Currently, the wearable antennas offered on the market are mostly planar, specifically micro-strip patch antennas, because they radiate perpendicularly to the planar structure and their ground plane efficiently shields the human body. However, the efficiency and the bandwidth of patch antennas are directly proportional to the substrate thickness, and generally thicker is preferable. When antennas are embedded into garments, researchers have noted challenges to overcome such as textile fibers and skin contact affecting the performance of patch antennas, shifting the operating frequency, reducing bandwidth and effectively making the antenna more prone to damage.
Unictron’s embedded, high performance antennas– such as flexible LTE/ wideband antennas and SMT chip antennas– are popular solutions for wearable applications. With the drive to further miniaturize next-generation healthcare sensors and wearables, new alternatives are entering the market that allow the chip antenna to be mounted directly above miniaturized printed circuit boards (PCBs) or alongside coin-cell batteries. Consumer products that could be improved by this development include an array of smart devices such as watches, clothing, eyeglasses, patches, pills, and even adhesive bandages. We currently feature low-profile SMT chip antennas which have successfully been implemented in the design of Bluetooth earphones.
SCA Series- Low profile SMT chip antennas using combo GPS, WiFi dual and tri-band chips