30 September 2019
A simple guide to impedance matching for RF
6 July 2018
Portable tracking devices are now woven into the fabric of modern life. We have already come to expect them in smart phones and watches: health, food delivery, rideshare and security apps provide just a few examples of the new possibilities tracking devices have opened up. Bags, pets, and even keys have now been fitted with tracking devices to guard against loss. As tracking devices have become more sophisticated, the revolutionary role they can play in analysing physical movement is being harnessed to drive improvement across a wide range of skills, from boxers to concert pianists.
Although consumers and industry have come to expect portable trackers to come in ‘smart’ devices as standard, the difficulties portable trackers pose for designers have not disappeared. In this article we’ll take a quick look at six key things engineers need to keep in mind when it comes to portable trackers, offering solutions along the way.
It may seem obvious, but it’s crucial to remember that portable trackers need to be small enough to be easily carried around and fully integrated into the final product. If their dimensions compromise the aesthetics or ergonomics of a device, users won’t be interested. To ensure satisfactory integration between tracker and device, the antennas that drive portable trackers need to be considered from the very earliest stages of product design.
Although there is a wide range of antennas available, the choice of RF technology (LTE / Bluetooth / WLAN / etc) will determine the number of options. Any decision needs to allow for the ground plane requirements, as these can have a direct impact on the final dimensions of the device.Using Antenova’s intelligent antenna selector from the early stages of design will ensure that your product uses an appropriate antenna: whether that’s flexible or ceramic, MIMO or LTE.
Portable tracker antennas need to be able to send and receive wireless signals from anywhere in their environment: they need to be omnidirectional. This poses a particular difficulty for designers as potential interference needs to be minimised all around the antenna. Choosing the right antenna and the appropriate layout of components within the device therefore becomes particularly important. All too often tracker operations are compromised by the operating environment, so this needs to be thoroughly understood, carefully modelled, and, ultimately, incorporated into product trials. Antenova offers full testing to see how effectively your tracker will send and receive signal, and can provide expert advice on design.
Since portable tracking devices generally tend to be small, the limited space on the PCB means antennas are inevitably placed very close to other components. As a result there is a danger of electrical noise from these interfering with the antenna signal. Some antennas, such as Antenova’s Inversa and Integra, are specifically designed to support co-location, but others have strict ‘keep out’ areas. Designers need to be very aware of this issue, and preempt how the layout of particular components will affect signal transmission. Send Antenova your Gerber files for an expert analysis of potential interference issues based on your needs, and our engineers will provide solutions for antenna choice and PCB layout.
Tracking devices can allow an unprecedented level of insight into all aspects of human movement. Frequently, this depends on close proximity to the body to ensure accurate and reliable information about physical location and specific movements. Unfortunately, the human body reflects and absorbs radio signals, potentially disrupting the RF signals trackers depend upon.
Designers need to consider the environments their trackers will ultimately be operating within, while being particularly attentive to how the trackers will operate with the human body. Ensuring that antennas do not come into contact with skin, using antennas with ceramic housing to isolate interference, or even using flexible antennas that can be mounted within clothing, can all be highly effective ways to ensure trackers cooperate with the body they should be tracking. Antenova’s intelligent antenna selector will help you make the right choice of antenna to ensure your tracker won’t be let down by its working environment.
A tracker system needs to be able to continuously send and receive signals wherever it moves. Maximising range is therefore essential for portable tracking devices. If a tracker can too readily be moved ‘out of range’ it undermines the entire mission of tracking movement.
Guaranteeing range can be tricky for antennas, particularly when they have to be small enough to be easily carried around and integrated with other components in a device. The unpredictability of real-life usage scenarios can often reveal oversights in otherwise theoretically ‘correct’ solutions. Using an extensive range of testing scenarios is the best way to ensure that antennas will ultimately provide desired range: after this kind of testing, Antenova were able to guarantee a tracker designed to trace a boxer’s movements with a real-life range of 10 metres.
Tracking devices need enough power to ensure effective operation. Designers therefore need to pay attention the power draw of the various components. This is particularly important for antennas. Maintaining a good, reliable signal in large, noisy environments will inevitably use more power than devices operating in smaller, more controlled spaces. In addition, the volume and frequency of data transmitted will have a direct bearing on battery life.
To keep a device operating, not only does the battery have to be big enough, the method of recharging it needs to be simple. If the means of providing this power are not user-friendly, it can be frustrating. Failure to take power in to account early on in design stages can lead to cumbersome power supplies or make users regularly charge their tracking device just to ensure basic tracking functionality. In practise though, nobody wants to have to remove and charge their dog’s collar every night when all they were hoping for was an easy way to keep track of their new puppy.
As with all aspects of tracking devices, if power is taken into early account an inclusive solution can be found. Ensuring compatibility with wireless induction chargers, for example, is a good way to minimise the potential frustration of having to keep a tracking device charged.
Although portable trackers offer a very particular set of problems for designers, a range of exciting antennas incorporating ceramic and flexible features help ensure optimal performance. By considering antenna design and placement early on in the design process, there is no reason for any unexpected interference, transmission, or power supply issues to arise. Contact Antenova’s engineers and testers today to see how your antenna design and placement can ensure your portable tracker behaves just as you would hope.