20 May 2022

Crystals For Wildlife Tags and General Tracking

An under the radar application for quartz crystals is transmitter tags used for the tracking of both humans such as medical patients that require lifesaving location monitoring and wildlife including insects, reptiles, mammals, birds and fish.

Rapidly developing technology has completely transformed the capability of wildlife researchers and scientists to track animals of almost any size, in almost any environment. Whether an animal moves through a terrestrial, freshwater, marine or avian habitat, specialist manufacturers are now able to provide systems to track them using satellite, radio, acoustic, and archival monitoring solutions. Technology leaders in this field include companies such as:

• American Wildlife Enterprises
• Holohil Systems
• Lotek Wireless
• SafetyNet Tracking Systems

Small size, low weight and high reliability are key requirements for tracking crystals. The crystals also need to be optimised for high sensitivity at low drive levels, essential for extended battery life and responsiveness. Typical designs are in the 145 to 175MHz range and include 3rd overtone LT5 packages that are manufactured in quantities as low as 3 per channel depending on there being a tight enough channel distribution. Applications also use Fundamental mode 3.2mm x 2.5mm SM packages in quantities as low as one hundred pieces per channel.

The challenge in making such crystals is to make small quantities of each frequency channel economically. At the RFX Group, our Laptech Precision quartz crystal factory has been manufacturing custom crystals for transmitter tags for over 30 years. Laptech get round this challenge of small quantities of each frequency channel by grouping together frequencies in blocks and processing them until after the mounting stage. Individual tuning is then applied to the batch to populate each channel with the correct number of crystals. This method is most efficient and economical if the channels are closely spaced with no large gaps in frequency.

Currently, Laptech are developing a 3rd overtone 6.0 x 3.5mm SMD package that will allow a significant reduction in weight (from 250mg down to 60mg) compared to the LT5 package with the obvious potential benefits for the wildlife tagging and general tracking markets. This new design should be available 3rd quarter this year so please contact us to reserve early samples.